Gas and Oil Home Heating Furnaces - Ticking sound coming from vents

I just moved into a new house in KC, MO about a month ago. The heating system is a Lennox heatpump with a gas furnace back up.

Sometimes when the furnace kicks on, there is a ticking sound that comes through the two vents in the master beadroom. When this ticking noise is not present when the furnace kicks on, it always starts right after the furnace blower stops. The ticking noise continues for about 5-10 minutes and then stop but always comes back.

We have had the builder come out twice in the mornings and he says he has been at the house for over 30 minutes and the furnace has cycled on and off serveral times and he has not heard the noise.

After researching this, the answer seems to be that it is common noise from the expansion and contraction of the duct work. Does this seem right? Would this cause the noise to only come through two vents in the entire house? Any fixes?

Thanks in advance.

i would suggest that you have the duct sealed and insulated well. temp change may be causing this.

hvac4u,

What do I seal the duct with?

Thanks in advance