Heat Pump Compressor Fan turning very slowly


  #1  
Old 05-09-14, 07:19 AM
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Heat Pump Compressor Fan turning very slowly

My heat pump compressor fan is spinning at about 1-3 rotations per second, and that’s only after I nudge it to get it started. I've watched it trying to get up to speed for about 5 minutes, but then I turned the unit off to avoid possibly allowing further damage.

Before I call someone out for a repair I'd like to try and troubleshoot the problem and hopefully just replace as few parts as required.

Details:

1. It just started doing this the first day it was put into Cool mode, after a couple days of no heat pump activity at all due to comfortable weather.

2. It is a Tempstar unit about 8 years old.

3. The fan blade will spin, but only very slowly, after being given a nudge to start it spinning.

4. There is a buzzing noise that lasts a second or less that repeats about every 30 seconds or less while in Heat mode. This noise seems to cycle faster while in Heat mode than in Cool mode.

5. The air handler seems to be operating normally, just not blowing warm or cold air when requested.

I'm willing to try additional troubleshooting in order to possibly narrow down what parts are working and which ones aren't but I'm not sure what else to try.

Thanks

Adam
 
  #2  
Old 05-09-14, 09:58 AM
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Sounds like you have a duel start capacitor that's failed. Can you post the model number of the unit?
 
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Old 05-09-14, 12:58 PM
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Model number T2H336GKA100

Sorry. I should have posted this originally.

The outside placard says Tempstar TX-5300 (or maybe 5330). It's weathered.

The sticker says it's a:

Model number T2H336GKA100

Thanks
 
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Old 05-09-14, 03:44 PM
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I found the Installation Instructions for the outside unit (331823-701 R-22 Split System Heat Pump).

The unit has a 'Comfort Alert' Diagnostics device attached to the control box. (LED lights).

The lights I see (when set to "Off" at the thermostat) are:

1. Constant Green. Module has power. Supply voltage is present at module terminals.

2. Flashing Yellow (six flashes) "Open Start Circuit". Current only in Run circuit. Troubleshoot:

a. Run capacitor has failed.
b. Open circuit in compressor start wiring or connections.
c. Compressor start winding is damaged.

The unit was installed seven years ago, to the month, and has a ten year limited compressor warranty. The parts and coil warranty was for 5 years.

Hope this helps.

Adam
 

Last edited by adam500; 05-09-14 at 04:20 PM.
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Old 05-09-14, 06:09 PM
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I tried a couple more things before it got dark outside and started raining.

I was curious to see what LED error codes came up while the thermo was set to 'Cool' and cool air was requested. I had cleared the prior codes by turning off the power, then turning the power back on (at the breaker box).

1. I turned the power back on then waited at the unit for it to kick on. When the unit kicked on I was surprised to see a single pretty bright spark I THINK where the white power wire connects to the Contactor just after the wires enter into the Control Box (at the very bottom of the panel). If I'm reading my diagram correctly, this would be the Bottom Left-White Wire connection to the Contactor.

The wire looked a little burned near this connection, not terribly, but a little.

2. After the spark, the LED's game me the same Green LED (Power received) and the six flashing yellow LED's.

Also however there was a constant red LED, indicating "Trip"- Thermostat demand signal Y1 is present, but the compressor is not running.

Troubleshoot:

1-Compressor protector is open.
2-Outdoor unit power disconnect is open.
3-Compressor circuit breaker or fuse is open.
4-Broken wire or connector is not making contact.
5-Low pressure switch open if present in system. (Not sure if there is one).
6-Compressor contactor has failed open.

That's all I can do with it today.

Hopefully that might help a little.
 
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Old 05-10-14, 02:43 PM
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The buzzing is usually the contactor, either loose wire on the 24 V connection to the contactor or the contacts are pitted. I would also replace the capacitor.
 
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Old 05-10-14, 03:17 PM
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Thanks.

Just to be clear, the buzzing only lasts a second or less and repeats every 15 to 30 seconds or so. Neither the fan or the compressor runs, although the fan will spin once pushed, it just never gets any real speed at all.

I can see where they may be a 'not-so-great' connection from the 24V to the contactor. I also took a close look at the capacitor (hoping it was bad and the simplest of all things to repair). I'll try to attach it's photo. I didn't see any bulging but the top did look corroded and kind of oily, although the terminals looked to be clean with no corrosion.
 
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Old 05-11-14, 09:27 AM
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Cap looks bad to me. Replace it first.
 
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Old 05-11-14, 10:03 AM
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That brief humming is the sound of your compressor cutting out on thermal overload.

I agree.... that cap looks popped.

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Old 05-13-14, 08:33 AM
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I finally watched some videos about capacitors and contactors. I'm hoping my contactor is ok and that I just need a new cap.

I've figured out how to test the cap but testing the contactor I'm not really clear on yet.

I'd like to test it while it's still connected. I'll keep looking for info about how do it. Every source of info seems to be just unclear enough to keep me from thinking I really know how to do it (test the contactor).

Now I have to find where I can get a cap locally. You'd think an electrical supply house would have them. Local HVAC suppliers don't want to sell me one.
 
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Old 05-13-14, 08:47 AM
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Your contactor is electrically working or your compressor wouldn't have come on. So you probably wont need a meter to check it but look at the contacts.... if they are blackened or discolored.... it will be time to replace it soon.

Disconnect the capacitor. NOTE the wiring connections. Take it to a local supply house and say I need this capacitor replaced.
 
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Old 05-15-14, 05:11 PM
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Smile It was a bad capacitor. Woking good now.

I put the new capacitor in today and it seems to be working fine, both Heating and Cooling.

I'm so glad it wasn't anything more involved. I might have tried putting in a new Contactor (I bought one anyway) but not sure about going much further...although I must say, there is a tremendous amount of Heat Pump DIY info on the internet now.

I'm just glad I didn't have to 1) decide who to call and 2) deal with them trying to oversell the fix. When I started this project I was hoping to at least diagnose the problem before calling in the pros.

Thanks everyone for all the information and ideas.
 
 

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