Boiler Help Please

Henrynagel

I have installed an IBC HC-33-160 boiler and basically I am having problems keeping just the boiler pressure up when the system is not calling for heat. The system pressure is staying up just fine its just the boiler pressure that drops. As soon as the pumps kick on and start calling for heat then the boiler pressure goes back to normal operating pressure, and as soon as everything is to temp the pressure in the boiler slowly drops. I have bled the system and the all 4 zones (3 heating and an indirect fire water heater) but I am still having the same problem. My original though was that I had air in the system that was slowly causing the pressure to drop but it doesn't matter how much I bleed it the problem doesn't go away.

Zman

How is your system piped?
Specifically where is the expansion tank located in relation to the circulator?
Some picture would be helpful.

EBEBRATT-Ed

need pictures. sounds like an expansion tank issue as @Zman mentioned

Paul48

Can you point us to the piping diagram you followed when installing the boiler? http://ibcboiler.com/wp-content/themes/ibc/pdf/HC_Series_Installation.pdf

kcopp

What is the range of pressure readings? What do you have for a system? cast iron rads? Fin tube?