HVAC system banging after repair visit
Homeowner here with typical central townhouse system- Electric AC / Gas Furnace.
Last week had Carrier evaporator coil replaced (under warranty). They also added kick start, replaced external leaking plastic compressor valves with brass, cleaned blower wheel.
Since then, the system has been banging, but they want to charge me $ for another diagnostic call, until they can confirm banging is result of service.
Banging is heard most cleary at night, from bedrooms via the return air vent in the hall. However it occurs at all hours. (It doesn't seem to have anything to do with when blower goes on or off.) Last week heard about 30 bangs when the system was "off" at thermostat, and hadn't been on for many hours.
It sounds like banging is located at the basement interior unit and echoing throughout the ductwork? Banging is every second or so for 25 - 40 times then stops. And not heard again for hours. (Reminds me of bang heard before furnace would go in in my childhood home).
I can't imagine it's the delayed ignition I read about, as it happened when system is off.
Any thoughts on possible causes would be appreciated!
Thermal expansion or contraction of the ductwork maybe? It didn't do this at all before the repair?
"kickstart"? I prefer electic start myself. I'm trying to picture a folding level on the outside of a condenser. You'd need a good grab rail to keep your balance. Chrome would add extra style points.
I'll tell customers that a service/diagnostic may or may not apply depending on what we find. Any good company will stand behind there work and not charge you if its related to what they did.
They are trying to be up front and letting you know that if its not related there would be a charge. I changed a stat for a lady one time and a week or two later she had no cooling, she thought we should come out at no charge and fix the problem because it had to be the stat, the unit ran great for years until we changed it.
It wasn't the stat
If you like and trust them just let them find the problem, if its related to there work you should be fine
While I agree that any unrelated repairs should be billable, I'm not so sure about a "diagnostic" charge, immediately after they were out there doing major surgery to the system.
Why not? If its not related, then I just spent time diagnosing and traveling to the site for something that is new. If it is related then there is no diagnostic charge.
Originally Posted by sktn77a