Heat pump fan capacitor intermittent ?

[01rangerxl]

It has just started getting hot here (90F+) in the last week or so. Yesterday I was out of the house for most of the day. I came back in the mid afternoon to find the house at 88F, the compressor on the heat pump making a lot of noise, and the fan not spinning at all. I was able to push on the fan blades with a screwdriver through the grate and get it started. It has been running fine since. Temps got down into the 70s last night and the heat pump cycled on and off and this time the fan was able to start on its own. I went outside and checked whenever I heard it cycle on. I don't know much about electrical things, but I always sort of thought either a capacitor worked or it didn't. This one seems to be intermittent, unless something else could be causing the issue. Could the heat be having an affect on it?

 

[jstutz]

They can be intermittent. Mine did that exact same thing for a while and i found a replacement cap on ebay for 15 dollars and it ran fine for about two years after that. Then the compressor blew and i got a new unit. Find a replacement cap and just replace it. Its an easy job but if your not comfortable around electric be very careful or let someone help you.

 

[friendly_jacek]

capacitors and contactors are wear items in AC/heat pumps. Replace when in doubt. When I did my first repair, I replaced fan motor, as it didn't run. Well, the new one didn't run either. It was a cap, even though it looked OK. I replaced one more cap and 2 contractors since. I have 2 heat pumps that are now in great shape, even though they are 15-16 year old.

 

[01rangerxl]

I know how to cut the power to it and do minor electrical repairs, but I can't see where the capacitor is located inside of it. I've replaced them on air compressor motors and such before and they were just mounted to the motor. I guess this one is further down inside somewhere. It's a Lennox "Value Series" (tract house special) by the way.

 

[friendly_jacek]

I have lennox too. The caps are inside the control box in a corner of the unit. You need to shot down power for the external unit with compressor as well as the air handler indoors (2 separate fuses).

 

[edwardh1]

either cap or fan bearing

 

[SrDriver]

My guess is that it is the fan bearing. Does it have any fittings for oil or is it sealed? If you can oil it use a non detergent oil. HVAC supply shops sell oilers for that purpose.

 

[01rangerxl]

Originally Posted By: SrDriver
My guess is that it is the fan bearing. Does it have any fittings for oil or is it sealed? If you can oil it use a non detergent oil. HVAC supply shops sell oilers for that purpose.



Not that I can see, but I'm not sure. When the fan is running it's very quiet and it turns very smoothly with the screwdriver.

Originally Posted By: friendly_jacek
I have lennox too. The caps are inside the control box in a corner of the unit. You need to shot down power for the external unit with compressor as well as the air handler indoors (2 separate fuses).

Thanks for the heads up on shutting down the power on both.

 

[sleddriver]

I dealt with a faulty condensor fan motor last Dec when my HP stopped working. I checked the motor caps with a meter that measures capacitance and it was ~ 35% low, so I replaced it. The motor had been in there 20 yrs, running a lot, so she was due.

Pull the electrical disconnect outdoors before going in. Short the terminals of the cap with a screwdriver before checking it with a meter, if you have one.

Over time a cap going bad or losing capacitance can cause the fan and/or compressor motor to run hotter and pull more current upon starting. Checking these periodically can save you lots of $$$$ as they're much cheaper than a compressor!

Also, the fan motor itself could be stalling because of a dried bushing/bearing. You can check both motors with a current test, but this may be out of your league if you don't work with electricity.

If you hire someone to do this, be sure they check your caps and measure the current draws on all your motors, indoors & out.