Heating, Air Conditioning, Fridge, HVAC/Ticking sound from vents


We just turned our furnace on for the winter. It is only about 7 years old and before has usually been fairly quiet. However, now during the mornings when it first kicks on I'll hear a ticking or rattling sound. It wakes me up and for a split second I'll think it's raining outside.I only hear the ticking while it's on and about 5-10 minutes after it has shut off. All the ducts are metal, and I've vacuumed out all of the vents already. I've looked at other people's questions about this same problem online, and it seems it's probably from the metal expanding and contracting. How do I fix this problem? My vents are in the floor.

It is somewhat normal for metal ducts to make some noise.  As the metal heats up, it expands.  Checking the system for anything loose is a start. You may even consider having flex joints installed to give the ducts a bit of room to expand, which might help.  Replacing metal ducts with flex/fiberglass will take all of the expansion out of the system, removing the noise.


Heating, Air Conditioning, Fridge, HVAC

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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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