Hot water heater furnace not shutting off

[JeffAndPam]

On our first voyage in our (new to us) 05 Fleetwood Flair, we noticed when we ran the hot water heater, after a few hours it started spitting out very hot water.
After doing some testing at home (thinking it was a leak, attaching a valve to the end of the spout) I realized that the gas furnace never shut off after several hours. When I ran the hot water at the sink, the water was extremely hot, almost boiling.

CONCLUSION (TLDR):
Seems like our hot water heater thermostat isn't working (or something related). Is there a rather simple solution for this?
Pictured below is the external panel to the water heater unit. Below that is a close-up of an electrical component.

 

[GTS225]

On our first voyage in our (new to us) 05 Fleetwood Flair, we noticed when we ran the hot water heater, after a few hours it started spitting out very hot water.
After doing some testing at home (thinking it was a leak, attaching a valve to the end of the spout) I realized that the gas furnace never shut off after several hours. When I ran the hot water at the sink, the water was extremely hot, almost boiling.

CONCLUSION (TLDR):
Seems like our hot water heater thermostat isn't working (or something related). Is there a rather simple solution for this?
Pictured below is the external panel to the water heater unit. Below that is a close-up of an electrical component.


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Well, first....get rid of that quarter-turn shut-off valve in the overtemp discharge. That should NEVER be done, as the overtemp blow-off is a safety measure. (Not saying you did it.)

Usually, there's SOME way to adjust the water temp, (even if only a little) and it's typically right where you took those pics. Might be hiding behind that shut off I want you to get rid of.

Roger

 

[Rich W.]

Yes, you want your temp/pressure relief valve to function. Its a safety feature and disabling it could be much worse than a little water leaking out of it, especially in your situation where it appears to be functioning as designed (not faulty) because its actually needed. You can plumb in additional piping so it discharges in a place of your choosing but can’t have a shut off.

Also from the pic it looks like you might you have two wires (red and white) that arent hooked up to anything. Its been too long since I’ve worked on one of these and I don't have one to go look at, but might those be involved with regulating water temp?

Also wondering if temperature control is a function of the board. If so they are available on Amazon for around $60. Might take a little research to find out, but its another possibility. It should have a 5 digit part number like 33488 or 31501.

 

[JeffAndPam]

Well, first....get rid of that quarter-turn shut-off valve in the overtemp discharge. That should NEVER be done, as the overtemp blow-off is a safety measure. (Not saying you did it.)

Usually, there's SOME way to adjust the water temp, (even if only a little) and it's typically right where you took those pics. Might be hiding behind that shut off I want you to get rid of.

Roger

Indeed, that quarter-turn shut-off was my addition, and now realizing what a BIG mistake that was! Will remove it.

 

[JeffAndPam]

Yes, you want your temp/pressure relief valve to function. Its a safety feature and disabling it could be much worse than a little water leaking out of it, especially in your situation where it appears to be functioning as designed (not faulty) because its actually needed. You can plumb in additional piping so it discharges in a place of your choosing but can’t have a shut off.

Also from the pic it looks like you might you have two wires (red and white) that arent hooked up to anything. Its been too long since I’ve worked on one of these and I don't have one to go look at, but might those be involved with regulating water temp?

Also wondering if temperature control is a function of the board. If so they are available on Amazon for around $60. Might take a little research to find out, but its another possibility. It should have a 5 digit part number like 33488 or 31501.

Ok. Next steps (after I return from vacation):
1) Remove that extra shut-off valve I added
2) Check all wiring
3) See if I can find a part number on that board
4) See if I can find a temperature setting (as suggested by GTS225)

 

[AbdRahim]

If you need a new board, check out dinosaur boards

 

[Kevin D Pem]

Indeed, that quarter-turn shut-off was my addition, and now realizing what a BIG mistake that was! Will remove it.

If your asking for ideas what might be wrong! Stop where you stand. You are looking at a boiler. Not just a boiler but a fire tube boiler! The fact you replaced a safety feature with a standard valve is an indication you should seek a professional!!!

 

[Rich W.]

Dinosaur customer service page Used them a couple times for otherwise out of production boards.

 

[JeffAndPam]

If your asking for ideas what might be wrong! Stop where you stand. You are looking at a boiler. Not just a boiler but a fire tube boiler! The fact you replaced a safety feature with a standard valve is an indication you should seek a professional!!!

I admitted my mistake. When I tested after putting that on there, I realized I did need to seek advice from others. That's why I value the insight of people here. Posting that picture helped me learn.

BTW, doing more testing and digging around more, I found a potentially faulty thermal cutoff:

It had some corrosion on the end. Since they are cheap enough, I've ordered a new one and will test again when that arrives.

 

[Okie]

The water coming out of the temperature and pressure relief valve could be as simple as a bad T&P valve, I would start by changing that. Below that is a thick black cardboard cover covering two thermal switches, those are limit switches. Those are sold in pairs and easily changed.