Recommended heating system pressure
Hi all,
We have a natural gas fired boiler/furnace/whatever-it's-called heating system (i.e. I don't know the exact technical term for this machine. I do know that it boils water only for the heating system - we have a separate water heater for regular hot water use). The system supposed to heat the house by pumping hot water (not steam) to radiators throughout the house.
We've never had real good heat in the attic, because the water pressure was too low to reach that high up, and my father couldn't figure out how to adjust the pressure such that it should stay up - no matter what he did, it always dropped back down to 25 PSI. Now that I've learned a little bit about how the system works, I figured out how to raise the water pressure (by adjusting the pressure reducing valve on the cold water feed, and then tightening the locknut). So my question is: given that the boiler is in the basement, and it's got to handle a total of four floors of height (3 floors aboveground + the basement), how high should I make the pressure? Is there a "danger level" - an amount that I should not exceed?