Air conditioner shutdown noise

[achenier7]

Whenever the air conditioner shuts down, there is a 'clang' noise. as if a metal flap was closing shut. Is this normal?

The unit is 10 month old.

[HayZee518]

that clank or clunk is just piston slap and valve operation within the compressor. at one point it was compressing gas then not and pressures are equalizing. the vibration dampeners [springs] may be loose.

[achenier7]

Thanks for the information. I will have the company check it out...

[jnaas2]

If they installed a new unit they may of changed the fan speed for the a/c unit and air flow needed for the amount of cooling, you need 400 cf minute for each ton of a/c. The sound \you hear may be the ductwork flexing

[achenier7]

It is not really a 'duct' kind of sound. It is more like a slap immediately upon the cessation of the cooling cycle, like a flap closing (a flap slap???) . My concern is not the sound per se (you get to tune it out), but the wear factor that could be associated with the noise.

By the way, happy to report that here in Naples Florida the unit has been quiet these last few days, with only the swish of warm air coming from the heating cycle of the said unit!!

[handyman4life]

Actually, I had a small unit that made a clank noise when it shut down. Now, at first I wasn't concerned but after a while I thought that it might start taking a toll on the longevity of my system. I call the company and had them check it out (under the warranty) and it turns out that the machine was ready to break at any time. I don't recall exactly what it was (this was a few years ago) but it you might consider getting someone to look at it soon. My unit was less than a year old at the time as well.

[achenier7]

Thank you for the input re your experience. I will definitely call the company.