Boiler pressure

JR_2

Help,

I have a Crown boiler awi 195 with a 40 gallon mega water tank....

My pressure reads 14-15 when the boiler is not running and 20 when it is heating water....Are these settings ok?

Thanks all!!

Dale

Probably yes

They sound typical. 12 psi cold fill is the industry standard and the pressure will rise when the water gets hot, how much depends on how hot assuming room in the expansion tank. The idea is to watch the trend and track the pressures. If the high side slips up time for checking the expansion tank, or potable water inlets. Low side falls and where is the leak.

Fred Harwood

pressure

The volume of water in a closed heating system increases with temperature, hence the need for an expansion tank, and a pressure relief valve. The expansion tank should have sufficient capacity to receive and return the changing water volume, without exceeding the relief valve setting of about 30 psi.
The pressure swings you see result from cold water in the heating zones warming (and expanding) to boiler temperature on heating calls, then cooling (and contracting) between calls.
A difficulty can arise when the volume swings exceed the capacity of the expansion tank and the pressure drops enough to draw water from the boiler water feed valve but then blows the relief valve on a call for heat. Vicious cycle, so to speak, and a sign that you need a larger expansion tank, or that it has failed.

Unknown

yes

yes , all is normal