Loud banging from the AC compressor when drizzly outside?

[mpire]

I have a brand new AC system. Its been running just fine. Brand new lines, new system, levels look just fine, etc.

Turned it on when it was a little drizzly out and its got a loud banging noise, every time the piston moves you hear the bang. I don't know what causes this, but its the second time I have heard it and both times it was drizzly outside.

Today its about 50 degrees outside and I fired up the heat pump to do some heating and its banging like crazy. Two weeks ago I kicked on the AC and it did the same thing. In between I have run it pretty regular and its been smooth with no issues or loud noises.

Anyone seen this before? Its probably 9 months old, never had an issue before.

Video so you can hear the sound.

 

[Chevy-SS]

"Brand new"???? Who installed it? Sounds like bad compressor, but could simply be fan blade hitting somewhere. I'd call installer.

Maybe take cover off and look. But don't take anything apart prior to calling installer. If you dis-assemble it you may void a warranty.

 

[mpire]

Its not the fan blade. The fan spins up first and silent like, then the compressor fires up and starts banging.

 

[nsula_country]

Scroll compressors don't have a piston.

CT

 

[u3b3rg33k]

if this is brand new it should still be under the labor part of the warranty. call the installing contractor.

 

[bonneyman]

Could be the defrost control. The circuit boards don't really like being in the outside arena, and go screwy. If the thing is initiating and then immediately terminating defrost - when the unit doesn't need it - you could be hearing the reversing valve piston banging.

 

[walta]

Anyone got a logical reason it only happens in the rain?

If it is under warranty pick up the phone.

If not turn the hose on it bit by bit until you can make it happen over and over again.

Wild guess is one if the sensors gets wet and sends the wrong signal to the computer in the outdoor unit assuming it is a hi tech variable speed units.


Walta

 

[The Cobbler]

I'd be calling the contractor. that does not sound healthy

 

[mpire]

"Brand new"???? Who installed it? Sounds like bad compressor, but could simply be fan blade hitting somewhere. I'd call installer.

Well, I think you were right all along.

So the system fires up just fine today. No issues, no loud noises.

I go out and am looking at it. I bump it, and then it starts banging.

I think its the fan blade hitting the shroud, but it only happens when its chilly out.

There is over 1/2" of clearance on one side and less than 1/16" on the side that is making contact.

Also, the unit is about a quarter inch low on the side of the contact, I'm guessing it settled.

So... now I have to see if I can adjust the clearance on the fan shroud.

Apparently the fan starts up fine and when the compressor kicks in its just enough vibration to make it hit the shroud and then it just continues banging away.

Thanks to all the calmer heads for suggesting logical solutions.

 

[fitter30]

Could have a broken internal mounting spring. Compressor internals would be touching the case.

 

[nsula_country]

Could have a broken internal mounting spring. Compressor internals would be touching the case.

There are no "springs" in a Copeland Scroll, other than a flat spring in an undisclosed location inside.

If another mfg compressor, unsure.

I suspected fan hitting sheet metal, but you had ruled that out... Glad you found it.

CT

 

[mpire]

I had assumed it was the compressor because the fan kicks on and a few minutes later the compressor kicks on and the banging starts after that.

However, it appears to be an issue with vibration.

https://pascalliedcdnep.azureedge.net/concord/Concord_4HP15L_Tech_Spec_0919.pdf

This is the manual, I don't think it has a scroll compressor, idk. Its concord made by Lennox.

The fan shroud is plastic held on with 4 screws, I removed the shroud and reinstalled pulling it towards the side.

Looks like I got almost 3/8 inch now. Its running quiet again.

I put a couple plastic window shims under it to level it out better, I will jam some more dirt under the slab at a later date and reinstall the other two tie downs.

Closer inspection of the panels shows lots of bent parts on the side making contact, now I'm assuming my ******* neighbor kicked it.

 

[nsula_country]

I had assumed it was the compressor because the fan kicks on and a few minutes later the compressor kicks on and the banging starts after that.

However, it appears to be an issue with vibration.

https://pascalliedcdnep.azureedge.net/concord/Concord_4HP15L_Tech_Spec_0919.pdf

This is the manual, I don't think it has a scroll compressor, idk. Its concord made by Lennox.

The fan shroud is plastic held on with 4 screws, I removed the shroud and reinstalled pulling it towards the side.

Looks like I got almost 3/8 inch now. Its running quiet again.

I put a couple plastic window shims under it to level it out better, I will jam some more dirt under the slab at a later date and reinstall the other two tie downs.

Closer inspection of the panels shows lots of bent parts on the side making contact, now I'm assuming my ******* neighbor kicked it.

Sounds like a friendly guy.

Looked up Concord. All their Heat Pumps have a scroll. If you look down inside the unit a scroll will be a tall, narrow cylindrical shape.

CT

 

[mpire]

Looked up Concord. All their Heat Pumps have a scroll. If you look down inside the unit a scroll will be a tall, narrow cylindrical shape.

I didn't know that. I looked it up, I learned something new today.

 

[SGKent]

Closer inspection of the panels shows lots of bent parts on the side making contact, now I'm assuming my ******* neighbor kicked it.

It was the big homeless street rat that set up shop on cold wet days. His tent poles were banging into things.

 

[TRWham]

Could have a broken internal mounting spring. Compressor internals would be touching the case.

There are no "springs" in a Copeland Scroll, other than a flat spring in an undisclosed location inside.

If another mfg compressor, unsure.

I suspected fan hitting sheet metal, but you had ruled that out... Glad you found it.

CT

Yes, for Copeland the stator is pressed into the shell, so it is definitely touching. It's one of the first assembly operations.

 

[nsula_country]

Yes, for Copeland the stator is pressed into the shell, so it is definitely touching. It's one of the first assembly operations.

I am well aware of how they are constructed. We built 1.8M of them last year at our site alone.

LG presses their stator in the shell also.

CT

 

[TRWham]

You must be at Alliance. Had not connected those dots before. I was at Sidney and Welkenraedt.

 

[nsula_country]

You must be at Alliance. Had not connected those dots before. I was at Sidney and Welkenraedt.

Correct. Glad to meet you. Have to make a trip to Sidney this spring.

To the OP. Concord = Lennox = 95% sure we built your compressor in Louisiana. Not the unit, the compressor. Glad you found the interference with the fan contacting the shroud.

CT

 

[monkeyspanners]

Have heard of fan blades being porous, water gets into the porous bit in rainy weather and throws it off balance.