LOCHINVAR BOILER

[steviegee]

I'm an apprentice and today my boss and I installed a 80,000 BTU LOCHINVAR combi boiler, however the problem we are dealing with is that the basement new (aluminum) radiator is not heating up but the 2nd and 3rd floor (cast iron) radiator are working fine. I've purged the air from all radiators but still no heat. The supply in the pipes are hot but the strange thing is that the supply to the aluminum radiator are cold.. We've taken the air out and it'll get hot but after an hour it'll go back to cold.. Would appreciate the help.. It's driving my boss insane

[Porcupinepuffer]

I don't believe that particular model is a combi boiler. All combi models I install are minimum 199kbtu to properly heat the domestic cold water for on demand use.
Without really knowing the piping arrangement of this system in relation to circulators, zones, primary/secondary, it would be very hard to give you an answer for why this basement radiator isn't flowing.
It sounds to me like there's still an air lock. Do you know if this radiator was working fine prior to this install?

[Hgye]

Liquids take the path of least resistance, and it is easier for heat to rise.  You will need to install circuit setter valves to balance the flow so that it goes to the lower radiators.