Hi I am new to this. my mclain furance cp1304954 is about 20 years old. Heat works find but when heat goes on a loud noise comes on for a while then stops and starts evrey once in a while. Furance in basemwnt and can hear noise up in bedroom. Is there a fan in furnace. That is the kind of noise it sounds like.

hello. after an extended absence, i am back for some more valuable advice. i've had alot of questions in the past you have helped with. i have an evacuatated tube solar array that shares a boiler loop. i cannot have both the array and the boiler running at the same time because the boiler will then heat the solar array. so, watching these work together, i want to automate the hand off from the boiler to the solar array. i want to stop the boiler from firing,( ie now i just pull the gas valve power wire) when the array reaches 100 degrees, but let the pump run until the array reaches 134. the array starts pumping at 135. i can program this stuff to happen via a pc, but i am wondering how to turn off just the gas valve. Would i do this via a 24 v ice cube relay? i have a valant boiler, for now until either i have the cash to buy a more efficient one, or i have to buy it because of boiler problems. you have warned me about condensation in the stack and about putting cold water into the boiler. the way this is set up right now, i have neither problem and it has been running now for 3 years. thanks for your help.