I have a question about my heater.
Its a relatively new (within the last 3 years) 200,000 BTU Modine heater that is suspended in the greenhouse from the ceiling. It has electric ignition for the pilot light.
It replaced an older model heater that had the old inefficient manual light pilot light that burned 24/7.
When it was installed, it was connected to the existing system that vents to the outside. The chimney/flue was very tall and pretty big diameter.
Hurricane Irma knocked my flue off, and I had a new one installed. The new one is a smaller diameter and not as tall.
My issue is this.
I have started to hear a kind of bang or pop (its a loud noise) whenever the heater goes is on.
Before I had the new flue/vent put on, I never heard this noise. For 3 years.
I read on the internet that when a 'furnace' makes this noise as the heater STARTS, it can mean 'delayed ignition' of the gas, and that isn't good.
I also read that if it happens when the heater has been going and turns OFF, it is usually just the metal in the duct and flue work contracting because it expanded when it heated up.
I tried to test my system to see if I could tell when it was happening in the on/off cycle. But I have to stand outside the greenhouse, manipulate the thermostat, and hear from there. Not from in by the heater. As near as I can tell, it happens only sometimes when the heater comes on. But not every time it starts.
Are there any heater pros here who can advise me?
