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

 o
Hayward Heater Heat exchanger failures

Posted by ksc12c (My Page) on
Thu, Dec 4, 08 at 16:39

We had a salt water pool built three years ago. In those 3 years we've had the heat exchanger fail 4 times. All 4 times times it's been replaced under warranty. The last time if failed was less then 2 years ago. The fourth time the replaced the entire unit. Now that heat exchanger has failed again and it's not covered under warranty now.

The frustrating thing is nobody can tell me why it keeps happening. We keep the water chemistry correct checking the Chlorine,PH and Acidity. I've had to pool companies and the Hayward Rep out and everything checks out fine.

It's a saltwater pool. Could that be causing the problem?
Anybody suggestions?


Follow-Up Postings:

 o
RE: Hayward Heater Heat exchanger failures

Show us some pix of the equipment pad.
What are you using to lower the pH?


 o
RE: Hayward Heater Heat exchanger failures

Most exchangers are designed to withstand up to 6k in salinity. I doubt the SWG is the issue. I'll take a shot a blame a poorly installed tablet feeder that is siphoning back into the exchanger. That is the typical cause but you would think Hayward would have picked that up after the first failure.


 o
RE: Hayward Heater Heat exchanger failures

If the all of the chemical values are in line, really the only things it could be are; too much water flow or electrolysis.

I have seen stray current destroy a heat exchanger in a matter of months.

This problem can be however too hard to diagnose over the internet.

Most heat exchangers aren't really designed to withstand salt at all, they didnt change the copper alloys when salt systems became common place. They will shorten the life of an exchanger of my estimates of 10-15%.

You can use cupro-nickel heat exchangers to make them more chemical/salt resistant. I though Hayward switched their whole line-up to cupro-nickel.


 o
RE: Hayward Heater Heat exchanger failures

IF they are adding muratic or bisulfate through a skimmer, that could do it too.


 o
RE: Hayward Heater Heat exchanger failures

Jandy claims their heaters are rated to 6k in salinity.


 o
RE: Hayward Heater Heat exchanger failures

If they didn't chlormatic, I'd bet they'd void their warranties if salt was used.


 o
RE: Hayward Heater Heat exchanger failures

Make sure you have a chemical resistent check valve between the salt cell and heater. The check valve will keep gases from the salt cell from getting into the exchanger and ruining it. We have had some exchangers fail on salt pools. so far since installing the chemical resistant check valve we have not had any repeat offenders.


 o
RE: Hayward Heater Heat exchanger failures

A couple of updates:
The installed gas line from the meter to the heater is currently 1 inch. The installation guidelines for a 400k heater call for it to be 1.25 inches. Everybody missed that. Would that cause heat exchange failures? Hayward technical manager wants me to replace the gas line. We are using Muriatic acid to lower the PH. WE pour it into the deep end. I'm not aware of a chemical resistant check valve installed either.


 o
RE: Hayward Heater Heat exchanger failures

Are all the bond wires tied to the same ground? They should be. Verify that there is no stray voltage by checking with a volt meter from the house's main ground to the heater, pump, etc. with all devices running and when turned off.


 o
RE: Hayward Heater Heat exchanger failures

Additional Information:

The Chemical resistant check valve is installed. I didn't know what it looked like. I also included links pad site pictures. Hayward cover the repair under warranty, they just want me to upgrade the gas line to 1.25 inches.

Here is a link that might be useful: Pad Site Pictures


 o
RE: Hayward Heater Heat exchanger failures

I have had the same heater and SWG going on 3 1/2 years now without any issue.

It is probably one of the problems mentioned above, either chemistry or electrical currents.

I doubt that the gas line would have any impact other than flame outs if it were too small. That shouldn't affect corrosion though.

Can you post what your PH, TA, CH & salt levels are usually at? How far do you let them deviate over the course of the year?

Also, check to make sure the heater is properly grounded. I think I can see the wire attached to the side of the unit but you need to do a continuity check to ground to make sure.

Also, I do not have a check valve between the SWG and heater but when the pump is off, the water tends to drain in the other direction towards the returns.


 o
RE: Hayward Heater Heat exchanger failures

The photos help. The link is missing the h in http though.

Whoever plumbed this was incompetent. 1st 90 after the heater is too close to the heater. The check valve should have come before the TurboCell. The valve directing return water isn't centered,The return lines are not evenly spaced and too high off the ground. The lack of extra pipe between fitting is not conducive to repairs.

Recommendations: Starting from the return side of the heater, extend that line about a foot then drop the line to the pad with the 1st 90. Then a stub and the check valve and another stub and then the TurboCell. Dig up the return lines at the pad and make them evenly spaced. Move the pool sweep ine to the other side of the return lines to be cloer to the booster pump. I hope they used flex as it will make this easier. Replumb as needed to make it look neat. Don't reuse the valve. Use clear glue. Looks nicer. Blue is really for underground plumbing where moisture contact is more prevalent.

Check for stray voltage as I mentioned in my earlier post.

This should cure the heater core issues and make your equipment pad less of an eyesore.


 o
RE: Hayward Heater Heat exchanger failures

The 90 being too close to the heater is not an issue. The check valve that you see is not for protecting the heater, but to keep the spa from draining (odd way to do it teeing off the pool like like that). The Tee valve not being centered is splitting hairs, and it's elevation is insignificant.

I won't let people use clear glue above grade, because it's easy to forget joints. I expect people that do the pipe assembly do a nice neat job with a gray glue. But a clean job looks good regardless of the color of glue used. People tend to overuse clear glue have it run all over the pipes.

I think you are silly to suggest that they "Dig up the return lines at the pad and make them evenly spaced." This is incredibly not an issue, while being a pet peeve of your's nobody else really cares.

Besides the easiest way to resolve this it to tip the tee valve vertically and then looping it over to the right line.

I digress.....

Hayward does not require a check valve between the heater, and Salt cell. A salt cell only generates about 2-3 ppm at average flow rate (some commercial units more). So when the pump turns off, there isn't and incredibly high concentration of chlorine in the cell unless the flow switch is stuck closed and continues to create chlorine while the pump is off.

Personally, I would have to examine the exchanger and look at the erosion, or corrosion to make a better determination. Your Hayward rep should be capable of making this diagnosis.


 o
RE: Hayward Heater Heat exchanger failures

If the spa is raised, the shown check valve is correct ly placed.The spa has a pool return in it which would siphon off water thru that return to eith the pool's water level or until the water level in the spa drops below the return and lets air in.

If the heater core shows erosion, the internal bypass in the heater is malfunctioning.

The amount of pipe after the heater does matter. The water in the pipe will sink the heat that remains in the event the heater doesn't get a cool down cycle, like in a power failure.

Pet peeve or not, it's ugly and doesn't allow for future service. Home owners paid a good deal of money. Why shouldn't they accept it done neatly versus the it works mentality?

Good techs wipe any excess glue off.

Given the number of heat exchanger failures this forum member has experienced, stray voltage is my #1 guess. It may be coming from either a noisy ground or the cell.


 o
RE: Hayward Heater Heat exchanger failures

"The amount of pipe after the heater does matter. The water in the pipe will sink the heat that remains in the event the heater doesn't get a cool down cycle, like in a power failure."

When heaters had firebrick Heatsinks were essential. Since heaters now have insulation, or sometimes nothing. (master temp). They do not retain as much heat as they used to.

"Pet peeve or not, it's ugly and doesn't allow for future service. "

Yes, but why replace it after the fact. Make it right when is requires attention.


 o
RE: Hayward Heater Heat exchanger failures

Would the 1 inch gas line contributed to the Heat Exchange failures? The installation calls for a gas line of 1.25 inches


 o
RE: Hayward Heater Heat exchanger failures

Not ones that will cause it to leak.


 o
RE: Hayward Heater Heat exchanger failures

The salt cell was replaced in the middle of the Summer. Bottom Line is Hayward Technical Manager is telling me it's the 1 inch gas line that's the problem. He insists that the heat exchanger is sooting up. They won't authorize repair until the gas line is repaired. The builder is balking at me asking him to pay to install the correct gas line.


 o
RE: Hayward Heater Heat exchanger failures

What size heater is it, and how many feet is the gas line.

I would also ask Hayward, how a sooting exchanger would cause leaking.


 o
RE: Hayward Heater Heat exchanger failures

400k BTU heater roughly 8-10 feet of gas line. Flex tube at the heat side. Please explain Leaking? Hayward's theory is that a 1 inch gas line does not deliver the correct volume to the heater. This incorrect volume is causing the heater to burn incorrectly and soot up. I looked at the vent fan and don't notice any soot.


 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.
  • Please review our Rules of Play before posting.
  • 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