SPA heater, what would happen?

[Hulaomr]

Hello,
I move to a house where a pool heater was installed for the SPA, including gas pipe line, except that the gas meter it was not connected. At that moment, the owner mentioned he never used the heater and I suspected the gas line got leaked somehow and didn't pass the annual check.
A few months ago, I performed a test pressure from end to end (30 psi for 12 hours) and got positive results.
At this time, I'm performing an inspection of the heater and found many screws and nuts for the plastic case are rusted, the Automatic Gas Shutoff (AGS) terminals broke while extracting the cable connector and the High limit switch (HLS) terminal seems rusted as well. Besides these parts everything else seems acceptable.
Based on your experience, there is another part I need to take care of before performing any test?
It would be possible to use the PEX gas pipe of 3/4 (20mm) with length of ~68.5 meters from the meter area to the heater? Attached some pictures for reference.
Thanks in advance

 

[Hulaomr]

Below an additional picture (limitation on previous post)

 

[1poolman1]

Below an additional picture (limitation on previous post)

View attachment 559621

Given the corroded condition of those switches, thermister, union at the blower, and the lower bolts on the manifold, I would suspect the heat exchanger is damaged and leaking internally. Unless the heater was sitting out with the panels off, all that corrosion of the tub could be from water being pumped out of the blower into the cabinet. The main gas valve also appears to be corroded.

 

[JoyfulNoise]

Disassemble the header (replace all those bolts) and remove the entire manifold. Check the condition of the copper pipes and steel plate. If it’s all corroded and worn down then the heat exchanger is probably shot. You could get the heat exchanger pressure tested but it’s probably not worth it. All the seals on the manifold will need to be replaced too.

 

[Hulaomr]

Hi @1poolman1 and @JoyfulNoise, thanks very much for your feedback.
I took another photos of the main gas valve and disassembled the header.
From my point of view, the heater was sitting out during many years. As manner of fact, a some point, the owner took the pump from the SPA (the one connected to the heater) and moved it to the main pool (filter side) because the original was damaged got damaged. Additionally, the filter pump was set locally (without the EasyTouch at all) neither the SWG.
What do you think? Do you suggest to disassembly the chamber (top screws)?
Thanks






This end cap threaded seems vey rusted and I think it could be changed easily.

 

[oldprophet]

Given the corroded condition of those switches, thermister, union at the blower, and the lower bolts on the manifold, I would suspect the heat exchanger is damaged and leaking internally. Unless the heater was sitting out with the panels off, all that corrosion of the tub could be from water being pumped out of the blower into the cabinet. The main gas valve also appears to be corroded.

Where is the bottom of the heater?

 

[Hulaomr]

Where is the bottom of the heater?

Hi @oldprophet, I removed all the case including the bottom. The device was installed under a roof but due to various restoration jobs, it got dust inside.
Below some pictures of the bottom case.
Almost all the screws and nuts of the plastic case get rusted. I suppose from outside. It something that I will replace.
Thanks!

 

[JoyfulNoise]

The header and manifold don’t look terrible. Every gasket/o-ring should be replaced. The ones on it are shot. I would also replace that drain plug. They sell one made out of zinc. Also, I would test that thermal regulator - it should open up at 120°F which you should be able to get out of your tap water. If it doesn’t fully open under running hot water, it needs to be replaced. You can clean off the rust stains with Bar Keepers Friend cleanser.

 

[JoyfulNoise]

You want to make sure that the green ground wire has a very solid and clean connection to the chassis. The FENWAL uses the current sent to ground from the hot igniter to sense flame. The circuit is very sensitive to any resistance on the ground wire and can cause the FENWAL to not sense a flame which will lock out the ignition.

 

[Hulaomr]

I will need to change all this screws and nuts due to corrosion. I suppose it got water while cleaning the filter.

 

[1poolman1]

Hi @1poolman1 and @JoyfulNoise, thanks very much for your feedback.
I took another photos of the main gas valve and disassembled the header.
From my point of view, the heater was sitting out during many years. As manner of fact, a some point, the owner took the pump from the SPA (the one connected to the heater) and moved it to the main pool (filter side) because the original was damaged got damaged. Additionally, the filter pump was set locally (without the EasyTouch at all) neither the SWG.
What do you think? Do you suggest to disassembly the chamber (top screws)?
Thanks

View attachment 559638View attachment 559639View attachment 559640


View attachment 559641View attachment 559642View attachment 559643View attachment 559644

This end cap threaded seems vey rusted and I think it could be changed easily.

View attachment 559645View attachment 559646



View attachment 559647

A gas valve that corroded should never be put back in use. It is dangerous.

 

[Hulaomr]

The header and manifold don’t look terrible. Every gasket/o-ring should be replaced. The ones on it are shot. I would also replace that drain plug. They sell one made out of zinc. Also, I would test that thermal regulator - it should open up at 120°F which you should be able to get out of your tap water. If it doesn’t fully open under running hot water, it needs to be replaced. You can clean off the rust stains with Bar Keepers Friend cleanser.

Hi @JoyfulNoise,
The thermal regulator was tested as suggested and the results were OK Below a couple of pictures (open and close).
Thank very much!

AFTER HOT WATER (open):


WITH COLD WATER (close):

 

[Hulaomr]

A gas valve that corroded should never be put back in use. It is dangerous.

Hi @1poolman1,
Beside the exterior thread pipe, the small plate surface and the pipe fitting union, which other part you consider is corroded and could be dangerous?
Thanks in advance!

 

[Hulaomr]

Hello!
The chamber was disassembled and below some photos of the heat exchanger.
May we conclude that the heater was seated for long time and not used? In fact, would it have been used only a few times?
Thanks!

 

[1poolman1]

Hi @1poolman1,
Beside the exterior thread pipe, the small plate surface and the pipe fitting union, which other part you consider is corroded and could be dangerous?
Thanks in advance!

View attachment 559911

View attachment 559912

The main valve in a pool heater should never be in contact with that much water. Some condensation is normal.
Every school that I ever attended has taught, early in the class, that a valve that is subjected to water can "stick" and the heater should be taken out of service, even if that means disabling it. You document what was done and move on. Yes, the customer will get angry, and I only had to do it once.
If it sticks closed, no fire, no harm.
If it sticks open, the heater will continue to fire after the waterflow has stopped. The internal temperature of the firebox (combustion chamber) is upwards of 1500 - 2000 degrees. You don't want uncontrolled flame like that.
As the pool owner, you can do what you wish.
As a service tech, the minute I touch a heater to do a repair I become liable for any damage, or harm to people, that might occur. I've seen, twice, what a runaway pool heater can do. Fortunately, it was only property damage (once to the tune of about $2,000,000 in classic cars).
Since many pool heaters are positioned near the home, the risk is too much for me.

 

[JoyfulNoise]

Honestly, that heat exchanger and flame holder is in very good shape. It barely looks like the heater was ever fired up or maybe it was replaced at one point.

If it were me, I would put it all back together plumbing-wise and leave the lid off the tub. Then I’d run pool water through it for 24 hours to see if there is a leak. If the combustion stays dry, then the heat exchanger at least is good.

As for firing the heater back up, only you can decide if you feel comfortable going ahead with the old valve. Sadly they are very expensive to replace but, for the peace of mind, installing a new one may be worth it. If you do decide to go ahead with firing it up, you should at least do the test procedures for measuring the static and dynamic gas pressure at the valve. You need to run through a full commissioning process to make sure the heater is operating optimally. Again, it all depends on your comfort level in working with gas equipment and you acceptance of liability. If you don’t feel comfortable doing it, then you need to seek out a qualified gas plumber to do the startup and commissioning and pay them for it. Again, it’s money well spent if you can find a qualified plumber and they’re willing to do a thorough commissioning job.

 

[Hulaomr]

Hi @1poolman1, @JoyfulNoise,
Thanks again for your feedback. Appreciated.
I cannot agree more with you guys.
Once the sensors arrive, I will proceed as suggested in order to test for water leaking.
My plan its to have a functional heater with most of the parts tested (at least individually) in order to look for a qualified gas plumber and evaluate the whole system.
Once the whole setup is ready and test passed, I will change other parts, for example, the gas valve as you suggested. Do you think is a good plan?
Thanks!

 

[JoyfulNoise]

Hi @1poolman1, @JoyfulNoise,
Thanks again for your feedback. Appreciated.
I cannot agree more with you guys.
Once the sensors arrive, I will proceed as suggested in order to test for water leaking.
My plan its to have a functional heater with most of the parts tested (at least individually) in order to look for a qualified gas plumber and evaluate the whole system.
Once the whole setup is ready and test passed, I will change other parts, for example, the gas valve as you suggested. Do you think is a good plan?
Thanks!

Sounds good to me … the only downside is that parts are expensive. Sensors are cheap. But all the critical parts like the gas valve, ICM (Fenwal), blower motor, etc, are hundreds of dollars a piece easily. If you start down the rabbit trail of replacing one part and then having the next one fail (cascade failure), you have to either go all in and rebuild what you have or buy new. The cost of replacing parts can get so high that you’ve basically bought yourself a new heater.

It’s just a matter of how much money you’re willing to throw at this thing versus buying a new one and not having the hassle or anxiety of waiting for the next failure.

 

[Hulaomr]

Following with the individual testing, the igniter was evaluated, resulting in 82 ohms.

Do you think is will be OK or is too high?

In the blog it suggest 50 ohm but I saw many people reporting others values (like 75 ohms).

 

[Hulaomr]

Sounds good to me … the only downside is that parts are expensive. Sensors are cheap. But all the critical parts like the gas valve, ICM (Fenwal), blower motor, etc, are hundreds of dollars a piece easily. If you start down the rabbit trail of replacing one part and then having the next one fail (cascade failure), you have to either go all in and rebuild what you have or buy new. The cost of replacing parts can get so high that you’ve basically bought yourself a new heater.

It’s just a matter of how much money you’re willing to throw at this thing versus buying a new one and not having the hassle or anxiety of waiting for the next failure.

Considering the heater seems to be seated for long time and the previous owner never worry about it, It could means that the pipe line or gas installation could be the reason and I would like to be sure if it even possible before investing more on the heater. However, for that gas installation it will probably be required an operational heater for testing. May be wrong.