Return to the Pools & Spas Forum | Post a Follow-Up

 o
Pentair Minimax NT Problems?

Posted by slicerbbqer (My Page) on
Mon, Mar 3, 08 at 23:48

I am having problems with my Pentair Minimax NT. After sitting idle for several months I decided to fire up the heater. It will heat up for about 30 minutes, then just shut off. It tries to heat up again but just shuts off. After several cycles, the service light goes on and it shows a E05 or E04 code.

This happened about 2 years ago and the service guy replaced the DDTC, ignition module, gas burner etc. It worked fine for one season now this.

Any suggestions?


Follow-Up Postings:

 o
RE: Pentair Minimax NT Problems?

Which one is it? E05 or E04? Two different issues.

If you are firing, and then going off and getting an E05, your igniter is to blame. It may be glowing but it's getting weak. The diagnostic goes further but that is usually the fix. with inactivity, the igniter is always to blame. You really need to fire it off weekly to make it reliable.

E04 is a fan issue. If the fan is running and you get that code, you have a switch or tube issue. If the fan is running and the fan light is on at the back of the board, you have gas pressure issues.


 o
RE: Pentair Minimax NT Problems?

Actually E05 and E04 can be caused by the same problem.

Gas pressure problems likely cause the heater not to rectify (e05), and sometimes explosive combustion upon ignition (e04).

The air flow could be enough to close the switch but upon ignition it bounces the air flow switch out, and shuts the heater down w/ an e04 message.


If the heater starts up and immediately goes into e04 then it is an airflow issue or detection of airflow issue.

These problems can be very tricky to diagnose without the proper instrumentation.

I would say it would be one of the 3 problem. And I would check them in this order.

1. Ignitor (about the only problem most homeowners can solve themselves).
2. Gas Pressure.
3. Combustion air flow. (indoor only)

A modification to the airflow path could be required. This should be done by a trained technician. I have had to do this on several heaters in order to get them to work reliably. They can work with the pentair factory or local reps to execute this.


 o
RE: Pentair Minimax NT Problems?

Thanks for the replies. How do I increase the gas pressure?


 o
RE: Pentair Minimax NT Problems?

I replied to your e-mail. The gas valve pressure adjust is rarely a fix. Sometimes though. I would not direct you do that through a message board. I suggested in my e-mail that the usual suspects need to be checked first. Igniter, then the igniter and finally the igniter....

You said it ran 10 minutes and then dropped out. Need the answer to the current appliance usage at time of drop out and meter size along with pipe diameter on gas, distance from meter to heater and the amount in inches of 3/4 pipe on the meter and heater side.


 o
RE: Pentair Minimax NT Problems?

Repair-guy,
Just read your email and responded. Meter size is either 400 or 425. It is running a 1 1/2 inch pipe to the heater then reduced to 3/4 inch. Approximately 65' from the meter.

I ohmed out the igniter at 2000 ohm setting reads:044 at 200 ohm setting reads 51.8. New igniter? Would clening the igniter help?

Thanks again.


 o
RE: Pentair Minimax NT Problems?

Was that 51 cold or hot?


 o
RE: Pentair Minimax NT Problems?

Repair-guy,

That was 51 hot or warm. I just metered it again cold 69.7.

Thanks.


 o
RE: Pentair Minimax NT Problems?

That's a pretty good reading. I'd say you're going to have to get a guy out there at this point. for that thing to be running for 10 minutes and shutting off is an indicator of something real ticky tacky. I'm guessing a vac switch on the way to going bad. You really need to jump a few things out of the circuit and stare at it now. The only thing I have not seen posted by you is the length of 3/4 on both side of the main line. What is it in inches and how many fittings and what type? Your way within the gas line specs but you can't have much more than 18" of the 3/4 on either end.

What type of work was done in the past? Possibly a blower? You may have the wrong blower on there and it's actually sucking the gas off the igniter. There are fixes to the air mix that you might need too but that needs a tech. And, you really need a static and manifold gas reading to see what's up.


 o
RE: Pentair Minimax NT Problems?

Repair-Guy,
From the gas meter it is a straight 1 1/2" pipe into the ground from the heater there is a union 3/4 union and then a 90degree elbow into the heater, no longer than 18".

They changed the old temperature controller to a new DDTC, changed the ignition module, changed the air pressure switch,and the gas manifold assembly. Do you suggest a pool tech or the gas company?

Thanks again


 o
RE: Pentair Minimax NT Problems?

Was this a model that had the two igniter system? I'm wondering why all of that hardware was replaced. There is still a chance the ignition control is bad. Get a pool tech there. He can check incoming gas pressure. The key is the heater ran for awhile. If it fires and goes off and then locks out, that is pretty east to fine. You're in territory that requires clamping onto wires and watching running volts at the gas valve, etc and running gas pressures at the valve. I've seen this type of thing a few times and it can be a sticky gas valve, voltage drag to ground somewhere, sticky hi-limit, etc.


 o
RE: Pentair Minimax NT Problems?

What repair guy is really trying to say is "too complicated to fix over the internet, and make sure that the company you call sends out a tech that know what the hell he is doing"..

I hope you don't mind me putting words into your mouth =).


 o
RE: Pentair Minimax NT Problems?

Yeah, this is way beyond a message board. The NT is pretty much beyond a field tech too. The best tool to fix that monster is a saw!!!

Granted, we make a ton on fixing those. It's pretty much the ONLY heater that breaks down now. Guess that is why they stopped making it. It was a red headed step child from day one. But, it was a huge learning process for Pentair that actually produced good heaters as they addressed all of the problems. You're totally screwed if you have a model from 2001-2002. Those were the worst, aside from the first model year that were pretty much loaded up on trucks for a total redo.


 o
RE: Pentair Minimax NT Problems?

Yahoo. I finally fixed the problem. I called Pentair and they gave me a few tips to fix what they call a computer hiccup. I shut of all the power including the breaker box. Wait 15 minutes then turn everything back on starting with the breaker box. Wala the heater works again. Hope this helps others having problems with their Pentair Minmax.


 o
RE: Pentair Minimax NT Problems?

I'm guessing that's not a fix. Maybe a momentary lapse in the failure. If properly wired, the heater would be powered down every time the pump is off. ie, no voltage to heater. If the heater is wired to a direct power source, you should correct that.


 o
RE: Pentair Minimax NT Problems?

I have a similar problem. I turned on my Minimax NT last night for the 1st time this season. It ran fine for about 6 hours, but then my pool timer turned everything off including the pump and heater. Now today, when I try to restart the heater I get the E05 error code and no heat. The heater fan does turn on for a few minutes, but then I get the E05 code and the red service LED turns on.

Did I fry the ignitor when the timer turned off abruptly? (no water flow through heater while the burner is RED hot)? I assume the heater has failsafes to prevent against damage during a quick shutoff, but then again...

I should have turned that pool timer off when I ran the heater yesterday...uggggghhhhh.

Any feedback welcome. THANKS!


 o
RE: Pentair Minimax NT Problems?

Abrupt shut off would have triggered a high limit error. And no, they don't have a protection for what happened unless you have a fireman's switch installed (yeah right) or are on automation (and have the delay active).

The result is usually a lot of melted plumbing and a few header leaks. The igniter would usually not be affected by the shut off as that area cools immediately when ti goes off. It's the exchanger up top that takes the hit.

You may just have a bad igniter and if this unit is a standard, quite possibly the flame sensor got too hot or a burner ground melted.

You should have it checked out by a technician.


 o
RE: Pentair Minimax NT Problems?

my display reads 'HI' on start-up. Newer manuals say this means hi limit switch is dropped out due to 114 F I've tried all the basic stuff i.e electrical resets etc. whats next ?


 o
RE: Pentair Minimax NT Problems?

Do you have solar? A non-charged panel system will dump super heated water into the heater and trigger the HI error. Once primed with cooler pool water, the display should read the actual temp. If it continues to read HI, you have a bad temp sensor. Th high limit code is not HI.


 o
Pentair Minimax NT Problems?

I've had mine since Summer 2004. Today, went out to check water, noticed it had the "service" light on and the display showed ERR. Any thoughts? Was thinking about going to my local Leslies, but not sure if the chain is good with this type of problem. Anybody have any experience with them on something like this? Thanks, Bismarck53


 o
RE: Pentair Minimax NT Problems?

99% of the time it's a bad thermistor.


 o
RE: Pentair Minimax NT Problems?

Moved into house with Mini Max NT heater for pool - tried to fire it up and it gets as far as the heating light (water pressure and thermistat first) coming on and a click sound, but no flame. The service light comes on after it times out. Could it be a bad ignitor - the error message is E004, but the fan seems to be functioning well. Can I jump the contacts on the vacumn switch to determine if that's the problem? The ignitor has a short prong and a longer one - should they be the same length? Could there be air in the gas line - my understanding is that while it hasn't run in months, it worked well this Spring.


 o
RE: Pentair Minimax NT Problems?

It could be air if the gas was off. That will clear in about 5-6 tries to ignite. You'll have to switch off and on after 3 as it locks out.

Do you smell gas after the click? If you do , it's an igniter issue. If you don't and you know the line is not air locked, it could be a fan switch or a bad fan tube. Rats love the tube.


 o
RE: Pentair Minimax NT Problems?

There's a little click then a very short pop that occurs when it sounds like it's trying to ignite, and (if I'm not imagining it) a faint whiff of gas. I think the fan function is working as it should (the tube looks good too). I'll clear the gas line at the union coupling and try again. If it doesn't ignite should I buy a new ignitor? It sounds like that's the most probable cause (and the easiest fix).


 o
RE: Pentair Minimax NT Problems?

In most cases, yes an igniter would be next.


 o
RE: Pentair Minimax NT Problems?

In follow-up to my Jun 5th Pentair MiniMax NT posting above, I didn't run the heater all summer since I didn't need it. Yesterday, for kicks, I turned it on and it fired up just fine. No E05 error and it ran fine for a few hours. Tonight, I tried again and got the E05 error but minutes later tried again and it turned on and worked fine until I shut it down after a few hours. Is this still an ignitor problem on the edge of not working sometimes and working other times? Just wondering...


 o
RE: Pentair Minimax NT Problems?

Just put the new ignitor in my NT TSI - no change in symptoms - LED flashes triple - E04 error. The heating light comes on for maybe a second and I hear the clunk of the gas valve opening - but it won't ignite. The fan sounds like it's running at the appropriate speeds - the sheet metal inside has sealant around the seams - did it come this way? How critical is the condition of the gasket on the top grill? There was a lizard living inside the fan housing - turning it on blew him out. I did open the union coupling and bled out the air. What next? Thanks.


 o
RE: Pentair Minimax NT Problems?

Probably a plugged orifice. Do you smell gas after the click?


 o
RE: Pentair Minimax NT Problems?

When I turn my unit on, the fan starts up as normal. I never feel hot air coming out of it though. After several minutes, the fan turns off ... a few more minutes and it turns back on. After about 10 minutes or so, I get an error code E04. During the process, I'm smelling gas off and on.

Any suggestions?


 o
RE: Pentair Minimax NT Problems?

Bad ignitor or plugged burner


 o
RE: Pentair Minimax NT Problems?

Or a melted/cracked burner. These TSI heater are plague with problems like that.


 o
RE: Pentair Minimax NT Problems?

Is there a way that we can check and/or service this ourselves?


 o
RE: Pentair Minimax NT Problems?

If you are comfortable working w/ the gas train on the heater you can move it out of the way, and unscrew the burners then slide them out.


 o
RE: Pentair Minimax NT Problems?

Reading this post this could have been written by me. My mini max NT was bought in 2004. Two years ago had the problem of the heater would fire up then shut down. First after 10 or 15 minutes then gradually closer and closer together. The tech replaced the ignition and it worked fine for over a year. Now same thing is happening. It now fires up, you feel warm air then it shuts off. We changed the ignition module and it did not help.

Per the manual E04 could be the hi low limit switch. Is that hard to replace or should I just give up and call a tech when I have the money?


 o
RE: Pentair Minimax NT Problems?

E04 Is a tricky code, since many things besides the fan and airflow itself can cause the heater to give this error.

Is this an NT TSI model (it will say on the door) or just a regular nt model.

If its a regular nt model you could try opening the door and see if it fires. These heaters were plauged with airflow problems.

I would suggest having a technician look at it.

E02 is the high limit switch code.


 o
RE: Pentair Minimax NT Problems?

Thanks. Yes it is the NT TSI model. It does fire and you can feel heat then about 5 seconds or so the heat shuts off. I guess I'll have to spend the money on a tech. The weather is perfect for the hot tub and it is driving me nuts not being able to use it.


 o
RE: Pentair Minimax NT Problems?

We suffered a large power surge recently, all breakers on pool equipment electrical panel shut off. I didn't notice until this past weekend the LED panel on the Minimax was completely dark. I have turned the Minimax off & on using it's own internal power switch and reset the breaker on electrical panel but all still dark. In my research I think it might be the Minimax transformer. Any help appreciated.


 o
RE: Pentair Minimax NT Problems?

If you have a multimeter, check the power coming off the transformer. This is the lead w/ the white/orange plug.

It should read ~24vac


 o
RE: Pentair Minimax NT Problems?

We fixed ours this weekend!!

Our problem turned out to be the flame sensor. Took about 2 minutes and only cost $20.

Thanks for all your help, appreciate it.

Patty


 o
RE: Pentair Minimax NT Problems error codes

Also by the way, even though the manual says E04 is a fan issue it is not. When you open the unit behind where the temp displays there is a list of what the error codes really mean. I don't know why Pentair has not fixed the error in the manual regarding wrong error codes.

Good luck.


 o
RE: Pentair Minimax NT Problems?

Thanks Racket


 o
RE: Pentair Minimax NT Problems?

E04 is an airflow issue. Sometimes combustion issues can cause airflow issues.

It's odd that a flame sensor would give you E04 and not E05.


 o
RE: Pentair Minimax NT Problems?

I find it best to not rely on the err codes. They are only a sign of a problem and rarely point to the problem. For example, you can get an igniter failure but that failure may be due to a hard start which is a gas flow issue and not an igniter issue at the root.

The best way to diagnose is to know what it's doing. Does the fan kick on? Do you hear a click at the valve when it tries to ignite? Do you smell gas after that? Those are key elements to starting a diagnosis that will stick.


 o
RE: Pentair Minimax NT Problems?

I have a 2007 minimax NT that was installed with the pump and other equipment, but never connected to the gas line about two years ago.

I do have the oversided meter on the house, everything looks like it was engineered properly to support the 400k btu heater.

I connected the gas with 3/4 pipe as it was stubbed out in the pool area, and turned it on, with the pump running of course. I have the information from teh gas company to set the pressure on the valve with a manometer, but haven't done that yet or touched anything other than to turn the knob on the gas valve to on.

The fan turns on for a minute, then I hear a click/buz/hum that sounds like the gas switch is turning on for about two seconds then it stops, then the fan turns off and it does it all again several times until I get error E04.

I bled gas from the union, I can smell the gas there. There are other gas appliances in the house that are running. But when the gas valve appears to be turning on, I don't small gas from the jets, or if I put my finger in the path of a jet, I don't feel any air/gas coming out at all.

Could it be a bad gas valve? Any other ideas?


 o
RE: Pentair Minimax NT Problems?

If you smell gas, it is quite possibly a broken ignitor or plugged burner. If it has sat for some time, the burner is the prime suspect. When it clicks to turn on and then turns off, feel the sheet metal near the ignitor. If it is hot, you are good and probably have a web in the burners. If it is not hot, you have a bad ignitor to start with the diagnosis.


 o
RE: Pentair Minimax NT Problems?

You can also check for voltage on the blue gas valve wire. It should get ~24VAC when the heater tries to fire. Since you have the manometer, hook it to the manifold (right hand) side of the gas valve and see if you ever get a reading which would indicate an opening gas valve.


 o
RE: Pentair Minimax NT Problems?

Repairguy, Why not just look for the glow?


 o
RE: Pentair Minimax NT Problems?

Thanks for all the comments!

I did some further debuging, I did look for the glow of the ignitor, it was working. The hum definitely came from the gas valve trying to actuate after the ignitor was on.

I started by tracing the voltage 24vac on the blue and white wire going to the gas valve and it was there as expected. There is a red wire also on the connector, but there was no tab on the gas valve receptacle for it, so the gas valve was only using the blue and white wire.

There is an ignition control box behind a metal shield, mounted approximately behind the temperature controls on the door, that was blinking three times when the gas valve connector was unplugged, stating there was an ignition error.

I put the blue/white/red connector back on the gas valve and tried it again and it lit and ran fine.

I suspect the gas valve was just stuck for some reason, it was new and had never been used before and had been sitting for two years without gas connected to it.


 o
RE: Pentair Minimax NT Problems?

I have a Minimax NT TSI....I get the ERR code and inside 1 LED flash. I have replaced the thermistor and the flame sensor(old one was rusted). I still get the ERR code. I checked the voltage and it reads ~24 from the transformer. I called pentair and they said if I have already replaced the thermistor then it is the DDTC board.I am reluctant to fork over that kind of money without knowing for sure. Any help or advice would be apprerciated.


 o
RE: Pentair Minimax NT Problems?

Because of a faulty pool pump I have not used the MiniMax NT for 4 weeks. Right before I turned it on a little lizard crawled into the air vent and when it turned on there was a nasty sound and the poor creature was blown out in a couple of pieces.
After this incident I have an ignition issue since I do hear the click and do smell gas for a short period. Once the error code E06 popped up but not anymore. Is it difficult for a handyman like myself to replace the ignitor (if this is the case)? Or could it also be a clogged burner. The little lizard do drop eggs everywhere.
Appreciate the help.


 o
RE: Pentair Minimax NT Problems?

More info on my ignition problem.

My problem as stated above, it did light once, but then it did not light again. Same problem where the gas valve would hum/buzz for about two seconds each time, after the ignitor activated and glowed for about 8 seconds.

I called pentair and they said it was likely too high of pressure on the input of the gas valve. Further investigation showed that I had a maxitrol 325-5A gas regulator to the line that ran the house, but no regulator on the line that ran to the pool mechanical room. I have a 2lb gas meter, and 1lb is equal to about 26" wc pressure, so I had likely around 50" wc pressure on the gas valve, and pentair said it should be 6 to 10" wc.

I thought I would turn off the gas line to the minimax but I had the same problem. Without something to bleed off the pressure, even though the gas valve was off, there was still enough pressure in the line to keep the valve from opening. I released the pressure at the union and then the gas valve would click on, and then I quickly turned the gas back on, and it would ignite and start running. So that convinced me that I needed another pressure regulator for the minimax.

I put another maxitrol 325-5A gas pressure regulator just before the input to the minimax and now everything works fine. I used that regulator because there was one already on the house, and it was rated for an output of 6 to 10" wc which was what I needed. There may be a better part to use with the minimax, but that is what I used. I still need to set the pressure with a manometer to get the best burn efficiency from the gas, but the ignition problem and the buzzing gas valve is now resolved. Now when it turns on, it makes a quiet click noise and then I can hear the gas running to the burners.


 o
RE: Pentair Minimax NT Problems?

I have a 400 TSI, installed in 2005 and has worked for 2-1/2 years without trouble. Last fall, it died. Pentair Authorized Warranty Repair company has tried 3 times since November to fix and at a loss. The have replaced ignitor, ignitor module, and thermistor multipe times. Replaced PC board once. $1,500 to date. It works for a few days after each visit then gives E04.

Unit is within 20' of meter with either 1-1/4" or 2" pipe from meter to within a few inches of heater. When turned on, fan comes on for about 10 seconds, then about 10 secs later HEATING light comes on, hear a click and smell gas, then HEATING light goes off. Repeats twice before giving E04 code.

Any help appreciated.


 o
RE: Pentair Minimax NT Problems?

If it doesn't light but the glowing hot surface igniter gets hot and ignites the gas then the system shuts down and starts over, it's like to be be the flame sensor.


 o
RE: Pentair Minimax NT Problems?

TSI heaters are really problematic.

It's probably not that flame sensor, E04 is an air flow problem which can be caused by violent combustion blowing the air pressure switch open.

If I was looking at this heater I'd pull out the burners and inspect them for cracks. At the same time I would inspect the heat exchanger for soot.


 o
RE: Pentair Minimax NT Problems?

I was lazy and didn't pull my book out.


 o
RE: Pentair Minimax NT Problems?

Neither did =).


 o
RE: Pentair Minimax NT Problems?

But you could have written it :-)


 o
RE: Pentair Minimax NT Problems?

Not if you want anyone but me to understand it.


 o
RE: Pentair Minimax NT Problems?

Does anyone have installation instructions for replacing the hot surface ignitor on a Pentair MiniMax NT TSI? I am a very capable mechanic and home improvement person. I am not afraid of taking on any project.

Any help or guidance that you could provide me to find the instructions on the web or if you could email me the instructions, it would ba very much appreciated.

Thank you in advance.


 o
RE: Pentair Minimax NT Problems?

Disconnect wires at quick connects, undo the screw holding the ignitor and remove. Carefully place the new one in and secure, reconnect wires.


 o
RE: Pentair Minimax NT Problems?

Don't let anything touch the hot surface. Skin oils and other contaminants will cause it to shatter. As you know, they aren't cheap.


 o
RE: Pentair Minimax NT Problems?

Thank you very much! Is there anything else that should be replaced as a standard service when I replace the ignitor?


 o
RE: Pentair Minimax NT Problems?

I have a MiniMax NT gas heater, HTR-400-NT-STD-PH. It was installed August 2005. On the DDTC, only the power and pressure sw led's work. Everything else is blank and not responding to inputs. I reset the circuit breaker. No luck. Any other ideas or suggestions for trouble shooting?
Thanks.


 o
RE: Pentair Minimax NT Problems?

I have a Minimax NT. It works, but last night I turned on the heater and it only heated up to 80, but it was set to 101. I went out to the unit itself and it displayed a temp of "101" but it was not that hot. I then kinda played with it and it kicked on. Then it kicked off and the display showed "---". My guess is that the thermostat is bad, but I'm not sure what part to replace.

Thanks for any help.


 o
RE: Pentair Minimax NT Problems?

This is a pretty old post now, but when I saw NT I had to read some of the post. Repair guy and racket pretty much sum it up.

When you call Pentair's tech line and tell them your working on a NT, there is usually a pause, then a sigh.
Not a good sign. The only worse reaction is if you tell them it's a NT TSI.
Allot of people have been happy with replacing them with Mastertemps.
Good luck.


 o
RE: Pentair Minimax NT Problems?

I have a lot of NT parts in stock. This is because Pentair tech support sends some parts just to get you off the phone or perhaps doesnt have a clue what is wrong. The joke is NT stands for new technology. It should have been called the POS.


 o
RE: Pentair Minimax NT Problems?

OK i think it is the thermostat. Before the Unit was saying it was hotter then it really was, now saying "HI". What part should I replace, the "Thermistor Probe"? I have the polly header, and i believe the part number is "471566"

mikethepoolguy, you say you have a lot of parts, how do you have this part and how do i order?

My herter info:
Model 400DV
HTR-400-NT-LN-N H


 o
RE: Pentair Minimax NT Problems?

I agree with mikethepoolguy...The NT is a POS. We switched to the Hayward Universal H Series heaters last year and have not had ONE service call on them. Great product. Not like the old H Series.


 o
RE: Pentair Minimax NT Problems?

Nathan, I admit I was being a bit facetious, but let me tell you my latest NT adventure.

A member of my A-team goes on a service call, multiple issues including heater not woking. He finds the igniter not working, so replaces it. He turns on the heater and the new igniter explodes. He only has 1 igniter left and the job is 25 miles from the shop, so he calls pentair tech support in hopes he can fix it the same day or at least have the parts when he goes back. Pentair says it's the ignition control module, and give us the #'s to order. I check, dont have one in stock, so I order. All good so far, right? But noooo; tech makes another trip, 25 miles, only to call and say it was not the correct part. He calls back PTS and they say "oh no, thats not the right one" well no s--t. So I ordered the part again.

Today the customer comes, in person, to our office wanting toknow the status of the heater. I tell him the part is on order,but I can see thats not what he wants to hear. So I order the part again, this time next day air. By the way Pentair said they would not pay the shipping.

In a nutshell, I will either lose money on this job or will have to charge the cust. an arm and a leg to fix what will still be a POS. Remember I am aready out an igniter and have now ordered 3 ignition controls.

The part that really gets me is that this is NOT,by a longshot the first time this has happened.

Service people: Get the name of the person you talk to at any mfgr. so that if they are wrong you can tell the manager. Im not trying to get anyone in trouble, just get them trained properly or moved elsewhere.

Good luck to all POS owners.


 o
RE: Pentair Minimax NT Problems?

Maybe one of you experts can help. I am working on a Minimax NT and do pretty well on them but this one some former pool guy got smart and cut the water temp sensor wires, why I don't know but in order to get a call back! At any rate, don't need the sensor since it's run by an AQ master control anyway so I need to add a resistor to the board to bypass the temp sensor. Anyone know what the resistance reading from the water temp sensor is, thought it was about 160 ohms but don't recall. thanks if you know...


 o
RE: Pentair Minimax NT Problems?

Well I have a similar issue E04. Actually replaced the ignitor and checked the pressue valve, went as fas as by passing the pressure valve to see if that was the issue. One lead to the ignitor has 120V going to it, one has none. What should the voltage be to ground on each lead?


 o
RE: Pentair Minimax NT Problems?

I had some mice living inside the unit. I cleaned them out and the unit ran fine for 2 days. After shuting it down for a few days of rain I tried to restart the unit and I receive error code E04. The chart inside the unit says the code is ignition failure.

When I start the unit the fan blows but I do not hear the click and release of gas. Any Ideas?


 o
RE: Pentair Minimax NT Problems?

I have a pentair minimaxi nt 250 dv propane. I just got it was a unit that was never used but sat outside for years. I hooked it up plumbed, wires, and connected to gas. made sure it was hooked up for 120v originaly had a err code found out the thermister wire was broke fixed that reset heater by turning power off at unit then breaker let sit for 6 houra turned on breaker turned on unit comes on with water temp of pool set temp to heat to 100 the preasure light comes on then the thermastat light fan is on but no clicking sound or gas sound and no heat or heating light this unit was never lit ever any ideas or fix tips?


 o
Pentair Minimax NT Problems?

Pentair minimax nt, Have replaced the flame sensor and ingitor, The unit will start the blower heat up the ignitor, no click on the gas valve no 24 volts to the valve, there is gas before the valve, the it throws a EO5 code. Any Ideas? Thanks for the help


 o
RE: Pentair Minimax NT Problems?

No 24V to the gas valve, after the ignitor glows typically means that you have a bad ignition module.


 o
RE: Pentair Minimax NT Problems?

Reading these posts is definitely not giving me hope!!

I recently moved to a house that has an inground pool with a Pentair Minimax heater. THe pool itself was not closed by the previous folks who lived there and we had a foot of leaves and black water... (took me over a month of working on it every day to get it clear!).

I have a clear pool, but cold! I had a tank delivered and filled and was all set to go! I fired up the heater, it worked for a few minutes, (hot air coming out the vent, warm water going into the pool) then we heard some banging noises and it shut down with E04.

I tried to turn it back on, and it comes on, reads the temp but the fan doesn't come in and it goes back to E04 after a few minutes.

Is it hard to replace the fan?

No pool place will come out and fix it for a couple weeks and we have family coming to stay with us for the long weekend. (Murphys law right?). I was told by one place to take the fan out and clean it that a mouse might have gotten caught inside? Anyone else heard of that?

Thanks!

Cheryl


 o
Pentair Minimax NT Heater Err Code

I had a flood the other day by my pool equipment while the filter pump was running. The pump zapped and broke. I replaced the pump and now the Heater is showing Err code. I called Pentair. The tech had me check the thermistor and that was fine. He said it's probably my DDTC board. Before I spend $250+ I wanted to know if there was a way to test that or any other suggestions. Thanks in advance.


 o
RE: Pentair Minimax NT Problems?

How did you check the thermistor? Did you do the trick where you lick your finger hold it on the pins while the heater resets?

I probably have an extra, or used control board I would be willing to sell for cheap.


 o
RE: Pentair Minimax NT Problems?

Yes. And also checked the ohms while the system was on. How much for the board?


 o
RE: Pentair Minimax NT Problems?

Cheap, click on "my page" next to my name, then "send me an E-mail".


 o
RE: Pentair Minimax NT Problems?

I have had my 200 model for 3 seasons and just this year I found the thermostat faulty and replaced it, it worked for a while then I got the service light and it stopped working. After some work done by the pool company (they gave up and wanted to charge me $2700 for a new master temp), I now get all green lights, pressure, thermostat (no service light)ect but it will not fire and yes I have plenty of propane. the flame sensor was replaced and also a new fenwall (but without the new wiring harness. I did notice that the white wire was not landed anywhere.


 o
Follow up to Pentair Minimax NT Problems?

Just a note the fan does not turn on at all and I do not smell propane


 o
RE: Pentair Minimax NT Problems?

I was getting the code E04 ignition lockout. 2 different "repair" companies thought that they had fixed it, but the issue recurred shortly after. Finally a competent repair person seems to have solved the issue.

He made 2 adjustments. First was a possible gas pressure issue, as mentioned above. He adjusted the regulator feeding the heater to slightly increase pressure. Second was debris in the burners. He indicated that the burners have a fair amount of rust/debris in them, but they are sealed so he couldn't just clean them out. He cleaned off all of the rust/debris that he could from the exterior and then tilted them to force the debris stuck inside to the rear before reinstalling them. The heater fires on first attempt now, and has been working flawlessly.


 o
RE: Pentair Minimax NT Problems?

I first started having problems when the heater would only stay on for about 30 minutes and then shut off and back on. The winter came so I didn't worry about it. My neighbor is my maintenance guy and I asked him to look at why the heater stopped working all together. The service light was on and the error code was ERR. He called Pentair and he was told to replace the motherboard. Very expensive. He replaced it and he said it fired right up, but I wasn't there to witness it and I had no reason to not trust him. Well, he has replaced other things at a very high cost. I told him that I didn't need him to clean my pool anymore and I checked the heater before I told him that and it didn't work. I told him that he needed to fix the heater or replace the mother board. He now thinks that it is the thermostat. I have read the entire manual, but I'm new to this and I'm tired of getting ripped off! I hired him because two other companies ripped me off. Any suggestions?


 o
RE: Pentair Minimax NT Problems?

1) Start a new thread. Scrolling through 83 msgs is a PITA.
2) Tell us in the new thread the exact model number, age, symptoms, and any possibly relevant facts.

Thank You.

Scott


 o
RE: Pentair Minimax NT Problems?

Is the control board still saying ERR?


 o
RE: Pentair Minimax NT Problems?

installed new in 2005 ... worked fine for years
now suddenly after trying to crank it up all lights flash for a while and then i get the service light and err message come on but no code.
any suggestion?
thank you


 o
RE: Pentair Minimax NT Problems?

Err = 3 things

In order of likelyness.

1. Temperature Sensor
2. Control board,
3. Voltage, or transformer issue

The temperature sensor is easy to diagnose. Find the 2 small yellow wires coming from the side of the heater. It should be the only 2 pin plug on the back of the control board.

Remove the plug, shut the power off to the heater.

Lick your finger, thumb etc. press it on the 2 pins on the control board that you removed the temperature sensor plug from. Turn on the power, if the led say LOW you need to replace the temperature sensor.


 o
Pentair Minimax NT ER04

When I started up my five year old Pentair Minimax NT this morning, the blower worked but I received an "ER04" error message. I took off the front cover and there it was, a rat's nest! Sure enough, I examined the silicon tube and it had been chewed completely through (I had heard that rats love the silicon tube). After a quick trip to the hardware store for a $4 replacement tube and 10 minute install my heater is working perfectly!


 o
RE: Pentair Minimax NT Problems?

This thread started over 3 years ago. Amazing.

Scott


 o
RE: Pentair Minimax NT Problems?

My NT 400 will start to click. I smell gas then a loud bang. The blower works I looked at the igniter and it looks new. I checked the burners and they are a little rusty but no cracks. I cleaned the gas inserts with a clothes hanger. They were pretty clear to begin with. Please help.


 o
RE: Pentair Minimax NT Problems?

FYI to all reading this. The above "repairguy" is posting lots of inaccurate information. I would not listen to anything posted by him


 o
RE: Pentair Minimax NT Problems?

LP Sooting Up - Removed cleaned burners / heat exchanger and inducer motor. Checked LP gas pressure In: 11" Out: 10" Tried to adjust pressure up, but would not go above 10", would go down, but not any higher than 10". Ran for 8 hours, and then starting to soot up. Flames at burner outlet are blue (1/4", then yellow/ornage (2") ANy help?


 o
RE: Pentair Minimax NT Problems?

Too much pressure.

Scott


 o
RE: Pentair Minimax NT Problems?

mi displey marca HI COMO SOLUCIONO ESTO GRACIAS SE LOS AGRADESCO


 o
RE: Pentair Minimax NT Problems?

Like everyone here, i've hated this unit practically since installation. after spending about $1K repairing, was working well. Then it sat over the summer and when I tried to start it up, it would never fire. took off the front side and found an ignitor wire chewed in half. Fixed it and it started right up. I noticed the repair guy left the face plate loose, so I reinstalled it. Now it won't stay lit. Cycles through 3 times (fires, 8 seconds later shuts down). Get an E3 code. Take off the face plate...fires right up. What would cause this? It does not seem safe to run it without the face plate.


 o
RE: Pentair Minimax NT Problems?

Question: can anyone explain how the flow valve on the Minimax heater works? This is the valve with the spring and the "thermostat" looking element on the tip. It lives in the manifold tube where the inlet/outlets are.

Is there a way to test it? Thanks!


 o
RE: Pentair Minimax NT Problems?

After enough water is flowing through the heat exchanger, any excess flow is bypassed by pushing on the spring loaded plunger, allowing water to skip past the exchanger. This prevents excessive pressure and friction erosion of the heat exchanger.

Scott


 o
Pentair Minimax NT Problems?

I have a Minimax NT. it heats just fine, can run 24 hours no poblem. I turn spa heat on and it heats the spa and pool just fine, even if only the spa is on. found out valve was in the the pool suction position, which explains the week long spa heating process ive been having. turned valve to suction from spa, returning heated water to spa, and i get E04 error msg. when i return water suction valve from pool suction, the error goess away and heater lights off again.

any help?
thanks
dave


 o
RE: Pentair Minimax NT Problems?

Same question but different results. Already replaced ingnitor on my Pentair NT TSI. Still get Err04 code. Starts up w fire, when fan starts, it blows the flame out. After 3 cycles, it locks out.Been running for 8 years w Minor problems, ignitor.Possibly the Temp. sensor?


 o
RE: Pentair Minimax NT Problems?

Flow stack sensor is my guess....


 o
RE: Pentair Minimax NT Problems?

thanks will check it out.


 o
RE: Pentair Minimax NT Problems?

crazy turned it on last night and it works, WTf


 o
RE: Pentair Minimax NT Problems?

Great but if it works for awhile and never hits the set temp check that sensor..


 o
RE: Pentair Minimax NT Problems?

I have a Pentair Minimax NT LN problem. It was working just fine. Went out to turn it on a few days ago and it was displaying an Err. I shut it off to reset and it would work again. I had to do this for a couple of days. Yesterday, I went to turn it on and again it was still displaying the err. I shut it down to reset but no success. Same err code. Err. I shut it down, checked the thermistor. Cleaned it as well as the High limit thermostat. Put it back together, turned it on and again it fired back on. Great it was working. I then ckecked it a few hours later and it had shut down. Now it was displaying an E04. I tried to reset, but again no success. The unit comes on as if to be working. The display shows temp. The fan kicks on, I hear clicking, but it never fires up. This last about 5 min. Thn it shuts down and the display again shows E04.
Anyone have any idea what is going on?


 o
RE: Pentair Minimax NT Problems?

Ok, I put a new igniter in and a new thermister on the heater as well as cleaned out the Burner and gas manifold. Still getting the same E04 code. The blower is still working just cool air coming out the top. I did notice that I don't smell any gas when I turn it on


 o
RE: Pentair Minimax NT Problems?

Believe it or not, I must have the last MiniMax NT still functioning. Or at least I did. Mine was installed in 2002, so it is likely one of the earliest/most problematic ones. That said, it's run almost daily for 10 years with only occasional problems. I can't complain _that_ much.

Anyway, my heater is firing, sometimes, heating, then cutting out. The curious part is that the bank of 4 LEDs on the left side of the control panel (see pic) comes and goes. When they are on, the unit seems to run fine. When they turn off, the blower stays on, but the burner cuts out. The failure is intermittent - it seems like maybe by jostling the wires I can get it to work, but other times no amount of jostling helps.

Any ideas where to start debugging? My recollection is that ALL of the LEDs are normally on when the unit is running correctly.

We just had a lot of rain recently, though I don't know if that might be related.

Thanks!


 o
RE: Pentair Minimax NT Problems?

I'm a late-arrival to the Pentair Minimax NT Problem Party. Bought my unit from pool installer who probably sold me obsolete, problematic heater. Just acquired 2008. When did Pentair stop making Minimax NT's ? Unsure if it's a TSI, how would one tell ? In summary, my problem, now, late last season, neighbors can smell the gas smell when unit is firing up, 4 neighbors away. Neighbors have called gas company and 911 on me. Pentair Tech, not pool installer came out, Tech said "All appears to be working correctly. He surprised my unit has lasted so long. (It's only 4 yrs old ???) And, it's time for a new one ! (What ?!?!)" What's the opinion of the Forum/Blog here, buy a different Pentair ? Switch to Raypack Rheem ? or Hayward Universal Heater ? Need a reliable heater, outdoors Chicago, 400,000 BTU for 2014


 o
RE: Pentair Minimax NT Problems?

I have a pentair minimax nt 400. all I get is a power light. nothing happens when switching to pool/spa. Have new propane and installed new oem board but didn't help. Ideas


 o
RE: Pentair Minimax NT Problems?

My Minimax NT TSI w/DDTC does not start. The green power button is lit up on the DDTC but the display only shows "OFF". No error code is shown, but the heater never starts. Is it possible that the thermistor probe (part number 471566) is bad ? But if so, shouldn't there be some error code?


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Pools & Spas Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here