Pressure release valve (PRV) leak

[Mikibh]

I have a burnham alpine 105 heater and when it gets hot the pressure release valve starts leaking, plumber tried to replace the valve and it didn't help.
I think the issue is that the expansion tank is located after the calculator pump and it should be moved to before the pump. is it correct that you should pump away from expansion tank. My current config is Boiler\Pump\Air Scrubber\Expansion tank house. and i think it needs to be Boiler\Air Scrubber\Expansion tank\ Pump\House is this correct?

Thank you

 

[johnjh2o]

The location of the tank doesn't make any difference. The tank may need to be replaced. The bladders in the tanks are known to fail.

 

[Mikibh]

IF the Expansion tank is bad would it not be full of water, when the problem happens it seems like the expansion tank is empty, full of air?

 

[johnjh2o]

When the PRV opens what is the pressure gauge reading?

 

[Mikibh]

When the PRV opens what is the pressure gauge reading?

It's showing 20 psi and the Prv drips slowly, only happens when boiler is at max temp 175

 

[johnjh2o]

The PRV shouldn't open below 30 PSI. You may have a bad PRV.

 

[Mikibh]

This is the third Prv the plumber has installed

 

[klee181438]

Are you speaking of the T&P or the pressure reducing valve? The T&P relief valve (temperature and pressure) is the valve coming out of the water heater (shown in the first picture) and the Pressure reducing valve (PRV) is shown in the second. If the T&P has been replaced, check the pressure inside the home. If its over 80 PSI, the PRV could be bad, causing the T&P to leak. If both are good, there is a thermal expansion problem. Hope this helps

 

[johnjh2o]

Are you speaking of the T&P or the pressure reducing valve? The T&P relief valve (temperature and pressure) is the valve coming out of the water heater (shown in the first picture) and the Pressure reducing valve (PRV) is shown in the second. If the T&P has been replaced, check the pressure inside the home. If its over 80 PSI, the PRV could be bad, causing the T&P to leak. If both are good, there is a thermal expansion problem. Hope this helps

I think he is talking about a boiler not a domestic water heater.

 

[Mikibh]

I am talking about a furnace for radiator heat.

And I believe the problem is an expansion issue but expansion tank seems to be good. in the expansion tanks instructions it says it need to be installed on the supply side of the system and on the suction side of the circulator pump I am asking if the fact the expansion tank is installed after the pump could be causing this problem.

The valve leaking is a pressure release valve coming out of the furnace. that should only unload at 30 psi.

Thank you
Miki

 

[paulplumb]

You have now had 3 PRV's installed. Has this been happening since the system was installed? Perhaps the expansion tank is undersized?