Hayward H250IDL2 Overheating

[G-man1]

Hi All, Here's my first post on this forum. My vintage Hayward H250IDL2 heater top started getting way too hot and the water is now taking way too long to heat up. I could smell something was not quite right...smells like a chemical burning smell which I attribute to the unit overheating. I pulled the header off first and put in a new thermostat. All good in there, but the the same overheating problem persists. I dug a little deeper today to get a look at the heat exchanger. It looks weird. Any thoughts on my next steps?

Kind regards!!
Greg

 

[ajw22]

Welcome to TFP.

@1poolman1 @swamprat69 may have ideas.

 

[1poolman1]

Welcome to TFP.

@1poolman1 @swamprat69 may have ideas.

An awful lot of soot build-up on that exchanger. That will definitely cause the overheating and warping seen. Need to check for proper gas pressure. Is the heater fed by a 3/4" pipe or a flex line? Is there anything on the burners, especially below the area at the bottom of the picture with the most soot? How old is the heater? It is called "vintage. Sometimes the actual burners on a Hayward heater will have burned themselves to the point that the flame is too large and will cause this as well.

 

[G-man1]

Thank you for the response. Its fed by a 3/4" galvanized pipe and its not been adjusted at long as I've been in this house. I think the heater is at least 15 years old. I've been in this house for 10 years...keeping this alive. I cleaned the burners last year and they were not too bad compared to other pics I've seen on the web but they did need a scrub with a wirebrush. The unit was just beginning to overheating then. I can take the heat exchanger out tomorrow and take a look at the burners. Your suggestion about flame size is interesting. Is there a good way to check? I looked through the viewing port before I dissassmbled the unit and the flame was all yellow. Does the warping mean the heat exchanger needs to be replaced? Thanks again.

 

[1poolman1]

Thank you for the response. Its fed by a 3/4" galvanized pipe and its not been adjusted at long as I've been in this house. I think the heater is at least 15 years old. I've been in this house for 10 years...keeping this alive. I cleaned the burners last year and they were not too bad compared to other pics I've seen on the web but they did need a scrub with a wirebrush. The unit was just beginning to overheating then. I can take the heat exchanger out tomorrow and take a look at the burners. Your suggestion about flame size is interesting. Is there a good way to check? I looked through the viewing port before I dissassmbled the unit and the flame was all yellow. Does the warping mean the heat exchanger needs to be replaced? Thanks again.

Heat exchanger can be cleaned, but generally requires that it be removed from the heater to do the job properly. You can try a vacuum with a brush attachment, but that won't get it of the underside. DO NOT use a wire brush. Soot is flammable in the right conditions.
Yellow flame is a soot producing flame. Should be a blue flame for proper operation. Likely cause is the burners are "burned" through, the slots are either too large now or there are areas that the slots have broken out and the flame is too large. Fifteen years is a good life for a pool heater, especially if it is used regularly.

 

[ajw22]

the flame was all yellow.

Flame should be blue not yellow.

Yellow flame indicates too little air or too much gas. It is burning rich which is the reason for the sooting.

 

[G-man1]

Sage advice. I appreciate it. I'd like to try a few more things before I send this one to the bin, but that might happen soon.

1. Could the unit be burning rich because the combustion fan is not "pulling" enough air in? Any way to check air flow in?
2. I will pull out the heat exchanger to see the bottom side and check/clean the burners.
3. I will check natural gas pressure.
4. Is there anything else I should check to improve fuel mixture?

Greg

 

[1poolman1]

Sage advice. I appreciate it. I'd like to try a few more things before I send this one to the bin, but that might happen soon.

1. Could the unit be burning rich because the combustion fan is not "pulling" enough air in? Any way to check air flow in?
2. I will pull out the heat exchanger to see the bottom side and check/clean the burners.
3. I will check natural gas pressure.
4. Is there anything else I should check to improve fuel mixture?

Greg

There is an air-flow switch that will allow the heater to fire when proper flow is reached. If flow is not good, the heater won't light. Hayward heaters have very thin burner tubes with hundreds of slots in them. When they are burned through you get that yellow flame. The slots near the ends, especially the end closest to the front of the heater cabinet, are usually still a good reference for how large they should be. Its the ones toward the middle and back of the burners that usually wear out the most.

 

[G-man1]

Right...should've thought of that. I will strip the unit down further and post pics.

 

[G-man1]

Here's what I found today. The burners and the underneath side of the heat exchanger. What do you think?

 

[JamesW]

Looks like the amount of gas was probably too much possibly due to excessive pressure.

Maybe the input pressure has been too high and damaged the gas valve or maybe the gas valve has failed.

I suspect that you are probably due for a new heater.

 

[1poolman1]

Here's what I found today. The burners and the underneath side of the heat exchanger. What do you think? View attachment 548853View attachment 548854

You could try to remove the burners and gently clean them, but the one at the igniter looks to be cracked or that may be a build-up off soot.
That is an awful lot of soot in the combustion chamber. This has been a long-time issue. Whether you can clean the burners or get a new heater (which may be the only good option), check your incoming gas pressure as that is the first thing to look for with the type of flame and sooting you have. Your heat exchanger also looks like it may be leaking as well (green deposits on the flange and tubes/fins).

 

[G-man1]

Excellent. Will check gas pressure. I brushed some burners a few times with a some fine grit sandpaper. The features that looked like cracks are gone, but the tops of the burners seem to be coated with copper and many of the nozzles seem clogged.