Loud Popping Noises - when HVAC is Turned On.

San Fran

Date is 1/1/08. I purchased a new stucco constructed home here in the San Francisco Bay area in May 2005. Late October 2005 when it started to get cold here I turned on the Heating unit and started to hear popping sounds in the masterbedroom, kitchen, great room and the foyer by the front door. The other side of the house where the additional (2) bedrooms are and (1) bath no popping sounds. Only in the rooms I mentioned. It is now Jan. 2008 and I am still hearing these sounds. The sounds, sound like a ballon popping. Very Very Loud. During the summer months when I turn on the A/C I do not hear these sounds. Only when it gets cold here October - March. I have had the builder supertindent and all subs here and they keep telling me they do not know what is causing the problem. I have informed them you built the house, you are the experts not me. I am not in the building business. It has gotten to the point where staying in this house is un-tolerable. The HVAC contractor who installed the unit has been out several times and he keeps saying there is no problem with the HVAC unit. But I am not convienced.

From an expert such as yourself can any one out there tell me what is causing these popping sounds?

Type of Heat - Central Air -
Noises coming from Ceiling.

Thank you - San Fran.
From the San Francisco Bay Area.

5kimprovements

When duct heats up it expands. it expands faster than the screws holding it together...the only fix i know of is removing the screws where possible and taping the joints with a ul approved foil tape......

bigMikeB

Sounds good but not very true. Trunk duts is never screwed together, it's held by slip and drive cleats. Only round or oval pipe would be screwed. The screws don't have to expand. Flue piping is just sheetmetal and always screwed together tightly and never makes a noise as it expands as you suggest and flues gases are a few hundred degrees hotter than hot air temps.