Relief valve leaking on boiler

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CTDIYER

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The relief valve on my boiler is leaking. I changed it and it continues to leak. I looked at the operating pressure and it's running at about 35 psi which explains why my 30 psi relief valve is leaking. I turn down the upper limit on the aquastat control to about 205°. It's still continues to leak. Any thoughts on what else can be causing this
 

johnjh2o

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If you have a expansion tank it needs to be drained and refilled. If you have a extrol tank it needs to be replaced.
 

Diehard

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John mentions one possible cause of an over pressurized boiler. Namely an expansion tank that has lost it's air cushion and has lost all or some of the space that would typically allow the heated water to expand to.

Another cause could be a faulty PRV(Pressure Reducing Valve) on the automatic water feed system, which is typically set down around 12 to 15 psi.

@John...Out of curiosity, why do you say, "If you have a extrol tank it needs to be replaced."?
 

johnjh2o

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If he has a extrol tank and the balder has failed there is no way to repair it other then replacing it. I also agree it could be the PRV valve. That can be conformed by turning the valve off on the feed.
 

Diehard

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If he has a extrol tank and the balder has failed there is no way to repair it other then replacing it. I also agree it could be the PRV valve. That can be conformed by turning the valve off on the feed.
Oh I see. You are assuming the bladder has failed but that may not be the case.
You made it sound like if they have an Extrol tank, get rid of it. Period!
Could be needing air due to an uncapped, leaky schrader valve. ???

I never had a bladder tank. I still have my original bladder less expansion tank. Well over 43 years now.:)
 

johnjh2o

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Oh I see. You are assuming the bladder has failed but that may not be the case.
You made it sound like if they have an Extrol tank, get rid of it. Period!
Could be needing air due to an uncapped, leaky schrader valve. ???

I never had a bladder tank. I still have my original bladder less expansion tank. Well over 43 years now.:)
Sorry for the misunderstanding. Extrol tanks are the new norm and they require less maintenance then expansion tanks. Although years ago I installed may expansion tank.
 

CTDIYER

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Thanks everyone for the feedback I'll check the expansion tank and the PRV.

I always thought the upper temp limit should be set at 210 or less
 

Diehard

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205F is well above the typical recommended average.
180F I believe is the average.
There are variables that could favor a slightly higher or lower setting.
 

Diehard

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Without getting into it, as I'm not that familiar with this stuff, but isn't more efficient to have it based on ambient temperatures. I believe there are system that automatically regulate based on exterior temps.
I change mind from summer to winter but I have a tankless water heater on my boiler.
I would also think that the amount of radiation you have in a house could justify a change from the average setting.
Edit: just realized you were saying that 180F should be MAX. Yeah I believe I've seen 140 to 180F as the recommended limits.
 
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