Solution to Heat Pump defrost cycle noise for Carrier and Bryant

[ricklab]

I purchased a Bryant Heat Pump in July of 2003. That fall I noticed a loud wooshing/moaning sound whenever the unit went in/out of defrost cycle. I contacted my dealer and worked with Carrier tech support for over a year on this. They even gave me a new unit which made the exact same noise. Finally they told me they would take my old unit and run it in a tesing facility to isolate what was making this noise. They called it the "moose call". They determined it was the reversing valve and would replace mine as soon as they found a replacement that worked. The new valve was installed on 11/26/2004 and it seems to be fixed. My dealer ran the unit through multiple defrost cycles and it sounds completely different. The woosh is much quieter and the "moose call" is gone. So far so good. Hopefully it lasts. I give credit to the persistance of my dealer and Carriers tech support person, Kurt Peterson. He works for Carrier Northeast at 860-635-6500 ext 5.

[Ed Imeduc]

All heatpumps will make some noise from the 4 way valve
in the outdoor unit. When it goes to defrost the valve works cause the unit is going into the AC set up. Some old units the valve would work when you went to heat. but they found out if the valve stoped then you didnt have any heat just AC. So now when the unit is off the heatpump is set for heat anytime . This way should the valve go out on you in winter you will still have heat but no AC or defrost.


ED ;)

[brent1]

Our newly installed Carrier Infinity heat pump makes a loud snorting noise, like an elephant call, or a tool box scraping on a cement floor. This noise lasts a second or two and only occurs in cooler weather near and below the freezing mark. Otherwise, it works fine. For the entire winter season on the coast, whenever the temperatures dips to freezing or below, we have been wakened during the night by this loud trumpet burst noise just prior to the unit going into its defrosting cycle. The unit goes into auxiliary heat to help defrost the outside coils outside and we see the steam rising.

Several visits by the installer and several calls to Carrier have been made but despite adjustments to dip switches and whatever else (no new parts) the noise persists.

It appears from the previous post that this noise problem has been around at least since 2004 and the fix required replacing the reversing valve which Carrier appears reluctant to do without putting the consumer to a lot of trouble.

Has anyone else experienced this problem?

[anitaj71]

My Carrier Heat pump is just one month old. It has started to get very cold - freezing temps and my heat pump also makes that loud Moose Call sound every once in a while. . . NOt impressed. It was supposed to be a quiet unit. I will call the installer and see if the noise can be repaired.

[zoneout]

Alot of units come from the factory with the default settings on the defrost circuit board. These circuit boards are not set for use with newer scroll compressors by default. There should be a jumper on the board to set a delay of about 30 seconds before going into defrost so that the pressure can rebalance. With the delay set the unit will run quieter.