Strange sound coming from the outside unit on Trane Heat Pump

berr3555

The past few days I've noticed that the outside unit has developed a humming/irregular sound, it sounds to me like a bearing is going bad. While running I listen around the unit and it seems like the noise comes from the upper part of the unit. When I put my ear close to the bottom the compressor seems to sound normal. But with all the different noises going at the same time is hard to isolate exactly where is coming from. I replaced the original fan like 3 years ago with a GE fan that I got from Locke. That fan failed within the 1 year warranty and I got it replaced. The current fan has around 2 years in the a/c. I was thinking of disconnecting the compressor wire out of the capacitor so the fan will run by itself to verify if is actually the fan what is going bad. I want to make sure that I do not harm any other component of the unit by taking this troubleshooting approach. Any help is greatly appreciated, thanks.

Fairview

-------------------------------------------------------------------


Sometimes a good fan motor DIY diagnosis is to watch the motor coast down. After a good reasonable coast down time I like to see the fan blade rock back in the opposite direction just a bit. With a bearing that's failing rock backs are uncommon.

That many motor failures aren't very normal so unless you didn't remove the drain plug a professional may need to determine why all the failures.

biggles

quick check shut the disconnect out at the condenser and free spin the condenser blade backward see if you hear rumbling or slight grinding..or it break stops real fast in either direction...for now spritz down the shaft some WD40 it will work into the top bearing.if you were in a winter snow area i would tell you to cover the top to keep the snow melt off the motor and i know the rain situation out there.does it mount up under the top of the condenser cover.did the old unit have a plastic rain guard on it between the motor and the blade?

berr3555

I came back to the computer to post that as it got warmer outside the strange sound went away, that is when I found the message by Fairview pointing out the drain plug. I went outside took the unit apart and bingo there was this little black cap installed at the bottom of the fan. I went ahead and remove the cap. I will post again if the issue returns. I want to thank of all you experts out there for giving me a hand in keeping my house in working order through out the years.

berr3555

Biggles I will get some wd40 and spray the shaft as suggested, as for the rain cap, if you are referring to the small (about 1/4") cap in the bottom I just removed it. Thanks.

biggles

na....the rain guard cap slides onto the fan shaft before the blade goes on if the motor is mounted facing up into the grill..if your looking at the back of the motor view into the top of the condenser forget the rain cap... the guard is usually made of plastic and is the diameter of the motor diameter..just throwing it out there to see if it ws there

berr3555

Well the sound returned, I will take it apart and see what is going on. It seems that the nose is only present when it gets colder outside. Please let me know if you got any suggestions.