speratic heat problems

spyderco

I recently worked in a house where they were getting no heat or speratic heat to their radiators. They had an old gravity hot water system, and recently replaced their old 200,000 btu boiler with a new 200,000 btu boiler, and now they are havig problems. I checked the boiler and it is running fine, pumps running with around 30 lbs. static pressure. Any advice.

Mike T., Swampeast MO

30# static is very high. Barring outrageously high ceilings, 12# is sufficient for three floors above a basement boiler.

The compression tank may be waterlogged (if the old plain tank) or improperly charged/defective if new bladder tank(s). With a waterlogged plain tank, you pretty well have to drain and re-fill properly. If the new boiler has a built-in air separator, make sure it's being used. If you rig the radiator system pump to run continually for a couple days, you can hasten the removal of dissolved air.

If the old plain tank is still in use, install a Bell & Gosset Air-Trol fitting on the tank--air problems will disappear. Make sure you follow the filling instructions.

Once filled, the pressure will usually rise 2-5# as the system heats.

jeff_51

sounds like you are air bound

and yes, 30psi usually will cause the relief valve to go. I run at about 22lbs when the system is a full temp. If the runs are air bound then the circ will of course not circulate any water. Try opening and closing the system valves a couple of times to "shock" the system. Sometimes that will cause a momentary change in pressure which is great enough to break an air bubble free. We use Spirovents even on radiator systems. May be a little overkill, but if it saves even one call back, it has paid for itself