Payne AC terrible noise

Pequod · 09-06-2012, 09:10 PM

I have a Payne PH13NA030-B. Manufactured in 2010 (in Mexico). When the unit is running and I turn it off at the thermostat, the unit makes a horrible, almost grinding noise. However, when the unit is running and I select a higher temperature, the unit cycles off normally (no terrible noise). Unless it's the compressor, my warranty is up and I'm SOL. Anyone have any ideas about what is making that sound? We called the installer and he said over the phone it was the "booster." I have no idea what that is.

I'm going to try and upload a video that includes the sound...

http://youtu.be/RVFOSqqAnac

Thanks in advance

Nick

**beenthere** · 09-06-2012, 10:05 PM

Links says. this video is private, sorry about that.

Pequod · 09-06-2012, 10:10 PM

Link should be public now. Thanks.

Doc Holliday · 09-06-2012, 10:19 PM

That only happens when the system shuts down such as by the thermostat? Or is it shutting down when it's supposed to be on?

Pequod · 09-06-2012, 10:23 PM

Hi Doc,

That sound only happens when the unit is manually turned off at the thermostat. It does not make that sound during normal temperature regulation i.e. when the temperature is moved up above the current temp displayed at the thermostat. It regulates the set temperature normally - no shutting off when it's supposed to run.

Apparently this started to happen after the thermostat was mistakenly switched from "Cool" directly to "Heat" although I don't see how this could damage the system...

Thanks

**beenthere** · 09-06-2012, 10:37 PM

Reversing valve is de energized when you turn the stat to off. With the unit running, pull the outside disconnect, and see if it sounds ok when it shuts off. if so, its just the RV being de energized at the same time as the compressor shutting off that is causing the noise.

Pequod · 09-06-2012, 11:49 PM

Thanks for your reply beenthere. For my understanding, the Reducing valve does not become de-energized during normal operation? This is a new sound. The unit has been good for 1.5 years then this sound appeared. I will do as you suggested and post back. Thanks for your help.

Nick

Doc Holliday · 09-07-2012, 12:01 AM

I'd like to tear into that unit to find out what that is. What a racket!

Sounds like a bearing maybe from the fan motor almost..?

If you are really handy and after you do what BT has suggested and if that is not it you can always disconnect one component at a time to pinpoint the problem.

You can turn the breaker off (pull out the disconnect), pull the fan motor wires off (making sure none of the metal plug ends are touching any electrical component, don't want to pop anything) and with the stat in the "Cool" position turn the breaker on/put the disconnect in. Now only the compressor should start up. After maybe 5-10 seconds, pull the disconnect. If that noise is not there upon shutting off than you know it's in the fan.

Then you can simply wire the fan back in and unwire the compressor and try again. This time the fan will spin without the compressor coming on. 5-10 seconds, pull the disconnect.

Which one had the noise, with the fan only running or with the compressor only running?

Pequod · 09-07-2012, 12:19 AM

Doc, Great explanation. I've replaced a contactor before so (I think) I'm up to your very detailed instructions. I'll give it a go. Thanks again for your problem solving tips. If I don't post back, I've been electrocuted! Hehe.

Nick

HVACDave · 09-07-2012, 09:01 AM

Sounds more like a pressure equalization taking place in the compressor. Can't explain the difference in how it is shut off though, should happen all the time if it's a valve problem.

Pequod · 09-07-2012, 02:07 PM

Perhaps the valve remains energized when the unit is in the cool mode and maintaining a set temperature? So when the unit is turned "off" at the thermostat (or by pulling the disconnect), the valve becomes de-energized as was suggested by a post above?

Thanks for your input.

Doc Holliday · 09-07-2012, 02:48 PM

If I'm not mistaken a reversing valve is energized on the low voltage circuit of 24 volts (thermostat control voltage and signal) while the disconnect breaks the high 240 volts. One has nothing to do with the other.

**beenthere** · 09-09-2012, 06:39 AM

See how many low voltage wires are ran to the outdoor unit. If only 2, then you need to run another one if you want to keep the RV energized when the stat isn't calling for cooling.