With winter coming I am trying to get a resolution to this. When the heat kicks on it sometimes makes a loud boom. It might do it once or twice a night. What causes this and how do I fix it?
what is happening to your furnace is a condition called rollout which is very dangerous. This happens when you have a clogged heat exchanger of a blockage of some sort in your chimney. Since the flames from the burners need air for combustion and there is a blockage the flames rolls out of the furnace and cause a loud boom. First of all do not use this furnace until you have it properly serviced and do not operate it without the burner compartment door on cause as I said the flame rolls out and can catch things in the room on fire.Also each time this happens it burns the electrical wiring in the furnace itself and after a few startups like that it will evenetually burn off the insulation on the wires which would mean you would need to replace the furnace.
roll-out is usually not a boom ....more like a WHOOF. I have to agree with the other poster. It sounds like your heating system is oil canning either the heat causing ducts to expand and change the stress in a certain area or when the fan comes on it is pressurizing in the supply or pulling vac in the return system. try to narrow the location down and often a smart hit with your fist will set it right permanently. (not kidding)
Agree with Wayne, your burners are not lighting like they should and you need to get it serviced to see why. Could be just dirt in the burners, but this is very dangerous. Gas is building up in the furnace and then when it hits the pilot light it explodes, hence the boom.
It could be heat ducts sucking in and out. If this is the case, you could fasten straps to the affected area and stuff a sponge in between.
