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Hydronic Boiler relief valve problem?

Releif valve is lifting when temp is up, but not when cold ?
Where should I first look to solve problem?

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  • Gio123 Nov 09, 2008

    My pressure relief valve keeps leaking when system pressure is above 20 PSI. I tried lifting it quikly and releasing it to clean it but I can't get to stop leaking.

    Should I change the pressure relief valve? or should I change my old expansion tank to a more modern pre-pressurized tank?

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Check the pressure guage. Typically the pressure in a water boiler should not be more than 20 psi. If you are approaching 30, the relief valve is doing it's job. I would replace or adjust the automatic water feed if the pressure is high. Always replace the boiler relief valve. Tap on the expansion tank, it should sound hollow. Replace it if it is full of water. If you have one of the old expansion tank that has no bladder in it, drain it.

Posted on Dec 04, 2007

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Posted on Jan 02, 2017

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