Hydronic Boiler is at 180 degrees but exceeds 30 PSI

KillaDilla97

I have a hydronic boiler when I set the hot water at 180 degrees my boiler goes past 30 PSI. What is the right HI and LO temperature water setting for a two-family house for Brooklyn New York.

SuperTech

High 180, low 160 is normally what I see. If you are at 30 PSI and your pressure relief valve is leaking then the issue is usually a failed expansion tank. 

EdTheHeaterMan

Can you show a picture of your expansion tank? It may be an older compression tank, or a newer diaphragm type tank with an air valve on one end and a pipe connection on the other. There are different ways to solve a waterlogged tank depending on what type you have.

When my techs found a leaking relief valve, with a 30 PSI pressure reading, I would instruct them to offer the triple repair of all three possible failed components, The Pressure Reducing Valve (AKA auto feed), the Diaphragm Expansion Tank and the Relief Valve. That would guarantee the problem was solved. If the customer was on a tight budget I would do a little more diagnostic to determine if all three were defective or if only one or two of them needed to be replaced.

If you show some pics here I can help you with how to determine what your next step might be. You may not even need any parts.

Mr. Ed