Hi, There are a couple of possibilites...not sure about good solutions though. The most likely is that the heater when it lights expands the metal inside, after a few minutes this metals springs or snaps from the built up tension of the expansion. This is harmless, except for the noise. The other possible cause would be more serious. That would that the gas could be not lighting immediately and building up till it all litles at once causing a bang...I really think you would know it if this was happening though. So.... I think my first scenario is the most plausible... The metal expands and contracts many times... the metal "grows" just a bit from the heating and cooling and now it just has no plase to go but POP out or in.... Not really much you can do about it, but I would get the covers off and make sure that you do not have a cracked heat exchanger, That could be very dangerous.....
Answers & Comments
Hi,
There are a couple of possibilites...not sure about good solutions though.
The most likely is that the heater when it lights expands the metal inside, after a few minutes this metals springs or snaps from the built up tension of the expansion. This is harmless, except for the noise.
The other possible cause would be more serious.
That would that the gas could be not lighting immediately and building up till it all litles at once causing a bang...I really think you would know it if this was happening though.
So.... I think my first scenario is the most plausible...
The metal expands and contracts many times... the metal "grows" just a bit from the heating and cooling and now it just has no plase to go but POP out or in....
Not really much you can do about it, but I would get the covers off and make sure that you do not have a cracked heat exchanger, That could be very dangerous.....
Heatman101
Yes,
Changing it would help ...but check on the price of a new one first because
it may be cheaper to replace the whole furnace.
Heatman101