Hayward Natural Gas 400FDN Heater

[jcrompton]

Our heater exchanger was recently replaced after a small leak had started. I usually do the work myself but the pool equipment was being moved so I just had the local pool guy do it. The heater has worked well for a few weeks except for a smell like , in retrospect , would have been burning soot -- but bottom line an odor that permeated the air all around the outside of our house.

Yesterday evening I raised the heater a few degrees in antcipation of the weekend - fortunately I was working outside when I saw the smoke. This is what I found.

Thoughts? I have not looked at the electronics yet - but assuming still functioning should I take the heater apart and look for some sort of soot build up? How is the best way to take apart - do I need to take the heat exchanger back out ??

 

[1poolman1]

Our heater exchanger was recently replaced after a small leak had started. I usually do the work myself but the pool equipment was being moved so I just had the local pool guy do it. The heater has worked well for a few weeks except for a smell like , in retrospect , would have been burning soot -- but bottom line an odor that permeated the air all around the outside of our house.

Yesterday evening I raised the heater a few degrees in antcipation of the weekend - fortunately I was working outside when I saw the smoke. This is what I found.

Thoughts? I have not looked at the electronics yet - but assuming still functioning should I take the heater apart and look for some sort of soot build up? How is the best way to take apart - do I need to take the heat exchanger back out ??

Not sure that heater can be saved. Not the first time I have seen that.

Most likely the refractory material lining the combustion chamber was damaged, possibly by the original leaking heat exchanger getting it very wet. Once the new exchanger was installed and the heater fired the water turns to steam almost instantly and "blows up" the lining. That lets the heat go to places it shouldn't, outside the fire box, and you have that kind of damage.

Also, that metal "cap" below the heat exchanger that is completely rusted may have contributed to the leaking heat. It is part of the "seal" that is supposed to keep the heat where it belongs.

Very good that you caught it early and that it is in a concrete enclosure. Pool heaters are great when they work properly, very dangerous when they don't.

 

[JamesW]

I usually do the work myself but the pool equipment was being moved so I just had the local pool guy do it.

The heater is a total loss.

For an indoor installation, you need a licensed gas contractor.

A pool person is not usually qualified to do indoor venting to a gas appliance.

What sort of air supply is provided for the heater?

What is the elevation of the heater relative to the pool?

What room is the heater in?

 

[JamesW]

What is the gas supply line size, length and pressure?

What is the heater model and age?

 

[jcrompton]

The heater is between 2 and 3 years old - Hayward 400FDN
Gas is 3/4 black pipe, I have not measured pressure recently but has never been an issue before , same line has been used (not at that time) for outdoor fire pit , etc

 

[jcrompton]

What is the gas supply line size, length and pressure?

What is the heater model and age?

There also seems to be some controversy re the vent kit -- Hayward suggests kit UHXPOSHZ14006
The kit on there was recommended by inyopool
I can't see any differnece in them but another person had said "that was the wrong vent kit". I attached a screenshot of the 2 side by side

 

[JamesW]

The heater is between 2 and 3 years old - Hayward 400FDN

Date of Installation?

Who installed it?

Who did the recent installation?

Gas is 3/4 black pipe,

That is not sized correctly for that heater.

It seems like there are several serious errors in installation.

You need a Licensed Gas Contractor to review the installation to advise you why things went wrong and to install the new heater correctly.

 

[JamesW]

What sort of air supply is provided for the heater?

What is the elevation of the heater relative to the pool?

What room is the heater in?

 

[jcrompton]

What sort of air supply is provided for the heater?

What is the elevation of the heater relative to the pool?

What room is the heater in?

Heater about 10 ft below pool level
Main room air supply - room is 28x20 ft with lots of ability for ingress of air
Outdoor garage pool equipment area

 

[jcrompton]

I think I found the issue !
I got home today and was able to open the front and examine the damage. Electronics seen fine. Tested and the only thing not working is the gas valve ….. it was near the heat of the fire and does not respond to the 24v pulse that is coming to it.

The issue was that someone that had last worked in the heater had not replaced the cover over the igniter. So the positive pressure of the fan was not effective for the positive pressure horizontal vent system ….. the air was just rushing out the large hole where the igniter plate was missing! I replaced it. Hoping it will still work!

 

[JamesW]

Heater about 10 ft below pool level

Do you have a flow switch?

At 10 ft below pool level the pressure switch will be triggered with no flow and it can destroy the heater.

That heater is not safe to operate.

I highly recommend that you get a qualified gas contractor to review everything and advise you on the best course of action.

Do NOT operate the heater until it has been approved by a licensed qualified gas contractor!

 

[JamesW]

Can you show this label?

 

[swamprat69]

Has anyone even checked inside the combustion chamber yet? Looks like a total loss that would cost more to repair than replace. Who was it that replaced the heat exchanger without noticing any other red flags? Is the vent piping just taped without any screws? New heater should be installed by a qualified gas contractor.

 

[TinFoilHat]

I wouldn't argue with the pros here. That is a scary proposition for anyone to try and fix. There is just too much that could be wrong now. Cut your almost-total losses and get a new one professionally installed.

 

[JoyfulNoise]

Suggest a new heater with an installation done by a licensed/NATE-certified gas plumber … or else you’re going to have a heck of a time convincing your insurance carrier why your house burning down isn’t your fault.