Cozy Propane Furnace Start up Noise

NJ Gimo

Hello-

We have a small place that is heated by a vented propane furnace. When the furnace comes on, it makes a clanking noise, and the same thing when it goes off, enough to wake you up at night. Is this the cold air contacting the combustion chamber, or just the metal expanding and contracting ?

Any ideas on what might be causing this ?

Thanks.

trollmastergeneral

Does the noise sound like soeone punched the duct work,or does it sound like a explosion.

NJ Gimo

Thanks for the quick reply.
The noise sounds like someone tapping on ductwork with a spoon, it starts out slow then gets a little faster and louder, then stops when the unit is hot and running. This noise sequence is repeated when the unit shuts off, when it does the whole thing again.

acefurnacefixer

Honestly we can guess about all day and night, its not going to make the noise go away and you will still be getting woken up. Since the unit is fired on propane, and propane can be very volitile, I would have the unit service by a pro,and consult with him about the noise while he is servicing the unit.

NJ Gimo

I should mention that the unit is brand new and was replaced once already by the manufacturer, and installed by licensed contractor, and passed all inspections.
The question might also be, is a loud banging noise inherent in the normal operation of these type of units ?
Any other owners out there ?

trollmastergeneral

I got to agree with ace on this one.It sounds like the duct work is expanding and contracting causing your problem. But you should have a profesional contractor look at the furnace , just incase.

NJ Gimo

It's a console type heater, so there is no ductwork. I thought it was a problem with the heat exchanger or something else.

trollmastergeneral

I would request that the contractor recheck the gas presure and be there to show them the noise you are hearing. The service person should be able to then tell you if thats normal.