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bypassing circuit board on hot tub

Posted by daljaz (My Page) on
Thu, Dec 17, 09 at 12:44

I have an 8 year old Leisure Bay hot tub that had a lighting strike, frying the circuit board and control panel. The parts to repair were costly and we did not think the spa was worth this cost. I opened up the access panel and studied the wiring and found that all the 4 components were 110 volt. The blower, main motor, jet motor and heater were all fed out of the circuit board by heavy 110 3 wires cable. I asked an electrician friend of mine if I could use 4 switches and control each component seperately and completly bypass the circuit board. He said it could be done, so I went to work. I bought a 4 pole plastic box, and 4, 20 amp heavy duty toggle switches and wired each component seperately. The result is I now have a perfectly functioning hot tub spending less than $50 for the repair. I broke the hot feed at the switches rather than using the common, this way when the switches are off there is no power on the system. The only problem is that I could not figure out how to wire in the original heater thermostat, so consequently I use a floating pool temperature gauge and when the water reaches my comfort zone, I just switch off the heater. I retained the heavy copper ground going from each one of the units and of course have a GFI plug at the power source. Everything works fine so far, and my wife and I can now enjoy our hot tub again. Everything is fully grounded as before, so we do not worry about shock. If anyone else would like to try this simply "fix" I will be glad to send more detailed instructions.


Follow-Up Postings:

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RE: bypassing circuit board on hot tub

Sounds like you defeated every safety in the system. You are treading very dangerous ground, very dangerous ground indeed.

Scott


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RE: bypassing circuit board on hot tub

The control panel has several safety switchs in it. I would be very cautious about doing this.


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RE: bypassing circuit board on hot tub

Not sure but feel the safety devices can be wired in bypassing controller. I once did the same thing, but didn't rewire switches in which how they were wired.


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RE: bypassing circuit board on hot tub

WOW!
Grab a couple of drinks and fire up that heater.

Make sure you have all of your affairs in order first:0

Do you get the feeling the profesionals on this forum are not behind your engineering feat.


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RE: bypassing circuit board on hot tub

I don't have a problem with the pumps being wired into switches, but the heater needs to have a functioning high limit, pressure (or flow) switch, and thermostat.


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RE: bypassing circuit board on hot tub-

I guess that was my point as well racket.


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RE: bypassing circuit board on hot tub

I'm not going to knock what you did, but the others here are offering some very valuable intel on the potential risks.
I've seen much more dangerous electrical repairs by homeowners to save money than yours.
If you only energize the heater when your in the tub the high temp limiter and t-stat aren't nearly as important as a flow switch. However, if your running the heater on your daily filtration time you really need them too.
Quite honesly I'm shocked that your spa is 120 volt. The ones we install require a 60 amp 240volt GFCI breaker.
Are you sure that you weren't looking at individual power wires which combined offer 240 volt. If so, and you wish to continue with your homemade fix you should swap out the 120 switches for 240 switches, and I'll bet you could find a flow switch that you could plumb into your return line rather easily.

See ya,
Kelly


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RE: bypassing circuit board on hot tub

Kelly Many spas are 120v, but they have 1.4 KW heaters, and the heaters shut off while the jets are on.


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RE: bypassing circuit board on hot tub

WOW!!!
This quote has me puzzled;

"""the heaters shut off while the jets are on."""

I don't ever remember ever seeing heater which energizes when the flow is off.
But, I'm no expert in heaters or self contained spa's.
All my work is new and renovation construction. I don't have a service and repair division.

I just find that strange.

See ya,
Kelly


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RE: bypassing circuit board on hot tub

Most (more than 95%) spas that are connected to a 240VAC 50 amp GFCI circuit or better can heat at the same time.

120VAC units can't because of the current draw when the pump is on High. Many that are connected to 120 can be U/Ged to 240 but not all.

Most spa pack covers have a schematic that will show if the unit will allow it.

Scott


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RE: bypassing circuit board on hot tub

I would think even in a 120vac hot tub, the heater needs some flow. Couldn't the pump be in a slow speed mode just to force the heater not to over heat, but not to draw more then the amps which a 120vac could power.


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RE: bypassing circuit board on hot tub

Spas at 120VAC and a two speed do exactly that. Switch to high and the heater element shuts off.

Scott


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RE: bypassing circuit board on hot tub

I think the OP is only running the heater for a short time beforehand and while actively using the spa. However, when wintertime rolls around and the water wont stay heated for a full day between uses, I have a solution.

Mount a standard $10 lower element water heater thermostat set at 104 degrees inside a watertight Lexan container, such as those made by GSI or Pelican, and float it on the water surface. Pass a right angle liquid-tight fitting thru a 7/8" hole drilled in the top of the container, run two 12 gauge wires thru liquid-tight flexible conduit from the thermostat to any point between your toggle switch and the heater. If you wish, you could bond a third wire between the mounting ear of the thermostat and the grounding system of your spa, taking care to bend the mounting ear in a manner that allows the thermostats sensor to remain flush against the bottom of the container. Run the flexible conduit from the floating container, across the water surface, out from under the spa cover, thru the spa cabinet, and to the heater wiring. Pack the container full of insulation to keep the thermostat pressed firmly against the container bottom to ensure good thermal conductivity. A second identical thermostat could also be placed in the container in series with the first and set at 119 degrees to serve as a high limit switch. When youre ready to soak, you can take the container out of the spa, and supply power to the heater sans thermostat the way the OP is currently doing. This would require a fifth switch which would, once again, supply power directly to the heater.

Unfortunately, I dont have an economical flow switch solution; as that is something Ive never put much thought into, being the direct immersion element sort of fellow that I am. Thats pretty far off topic here though.

Here is a link that might be useful: GSI Lexan container


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RE: bypassing circuit board on hot tub

Remind me to throw away the invitation to your hot tub party.

Why not just buy a cheap thermostat with a dry well, and call it a day. A pressure switch can be had for less than $35.


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RE: bypassing circuit board on hot tub

Im assuming you would decline my party invitation out of fear that, due to my frugal nature, I would have cheap beer and no-name pretzels. It surely couldnt be a safety concern, as both you and I both know that a GFCI breaker makes electric shock a non-issue. Being a farmer, I take a hit 3 or 4 times a year from an electric fence and imagine that it probably hurts far worse than the few milliamps you would get before a GFCI trips. Then again, Ive never been wet and naked when it happened.

I think the installation of my system would be just as quick and easy as yours, is far more universally adaptable, would be better within the capabilities of the OP, and would cost about a third of what you would have to spend on even the cheapest thermowell, thermostat, and high limit switch. To me, my fix just seems to be more in the spirit of the OPs project. If you were complaining about all the liquid-tight conduit, I only put that into the mix as overkill to alleviate any objections as to the safety of the set-up; but that got questioned anyway. In actuality, I would simply pass a length of 3 conductor 14 gauge SJT cord thru a watertight strain relief fitting in the Lexan box and bring it across the water and out from under the cover.

You are correct; a cheap pressure switch would be the way to go to prevent heater element burnout. I didnt realize pressure switches were so much cheaper than flow switches, and until just now looking, thought that all flow and pressure switches were low amperage, therefore requiring a contactor (the very type of thing the OP was trying to get away from in the first place). Thank you; youve taught me something without even meaning to.


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RE: bypassing circuit board on hot tub

GFCIs are not that fast. It's not a few milliamps @ 120 or 240. Its the potential 1-10 amp + blast that a sudden failure from shorted heater element a can cause. THAT can kill you and anyone else in the tub.

Its the excess heat that can cook you when the high limits are bypassed.

Its the law suits adding to the missery of being miserly and short sighted.

That and the cheap beer and doesn't help.

Scott


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RE: bypassing circuit board on hot tub

That's almost like saying, "you can use vinyl tube for the break lines on your car, because you can use your emergency brake to stop if it fails"

I have no problem with being frugal, but rigging up a pelican type box to hold high voltage electricity for a hot tub that you will be sitting in, is foolish.


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RE: bypassing circuit board on hot tub

And even if a GFCI breaker would clear fast enough, would you really trust your life to something assembled in the Dominican Republic (that's what it says on one I looked at)or some such place? I'm all for inventiveness and frugality, I just draw the line at sitting in water with a control circuit that has been modified. And stay away from those fences, your hair will end up looking like Carrot top's.


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RE: bypassing circuit board on hot tub

Yes, GFCIs are that fast. GFCIs made to United States specifications trip in 25 milli-seconds (1/40th of a second), which is more than quick enough to prevent the heart from going into arrhythmia (the US Navy did a bunch of research on the effects of electric shock back in the 1940s; anyone whos read the NEC codebook should remember this section). It wouldnt surprise me if in the state of NJ, where portable air tanks and hollow point bullets are outlawed in the interest of public safety, the mandated GFCI response time wasnt even quicker. Besides, when it comes to preventing shock from shorted heater elements; what safety mechanism beyond the GFCI and electrically grounded components does a new hot tub offer that mine does not? Residential water heaters are never GFCI protected; yet, whens the last time you heard of someone being electrocuted in the shower by a shorted water heater element?

I didnt bypass the high limit. My setup is even better:
-you test the water before getting in
-119 degrees, holy crap thats hot as dishwater
-aha you say; the thermostat must have gone bad since we last used the tub
-note to self: fix thermostat tomorrow
-turn off the heater, add some cold water to the hot tub, get in and enjoy
-observation to self: isnt this better than coming out to a tripped high limit switch and a frozen hot tub?

Cheap is subjective: Ill be serving Budweiser in bottles and Schneiders of Wherever.

Who wants a box floating around with them in the water? The Pelican box goes out of the tub before people get in; you then use the OPs method of regulating the heat while youre in the tub. Its impossible for the thermostat to get wet anyway, as the waterline never even gets close to the level of the seal on the Pelican box.


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RE: bypassing circuit board on hot tub

I sure hope that you don't have any young children around.


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RE: bypassing circuit board on hot tub

Indeed, no children. No one here but autonomous, freethinking adults.


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RE: bypassing circuit board on hot tub

If that's what you want to call it. I'll let it be.


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RE: bypassing circuit board on hot tub

quote" That's almost like saying, "you can use vinyl tube for the break lines on your car, because you can use your emergency brake to stop if it fails"
I have no problem with being frugal, but rigging up a pelican type box to hold high voltage electricity for a hot tub that you will be sitting in, is foolish. "quote

I'll second this reply.

I call myself practical while my wife calls me cheap. However, even in an effort to save money I will never do anything less than code compliant work at my house too.

See ya,
Kelly



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RE: bypassing circuit board on hot tub

This sounds like a great way to boil water the wrong way! Remember a car battery can kill you. A HID headlight controller can kill you! Both work off 12 volts and 120 amps.


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RE: bypassing circuit board on hot tub

Hey can you tell me how you did it my email is haskinsg1@gmail.com thanks


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