It has been one of the hottest summers with never ending 95+ degree days forcing my central air conditioning unit to work overtime. Although my unit is over 16+ years old, I have maintained it regularly so it is still in good working condition.
But one night, my son woke me up at 3am to complain that his room was freezing. True enough, his room thermometer indicated 71 degrees, which is much too cold while sleeping. So I trudged downstairs and checked on my Honeywell thermostat.
Maybe because I was still groggy, but I was confused as to why the air conditioner was running (I could hear both furnace blower and condenser fans running) when my thermostat was set to 76 degrees and the current room temperature was showing up as 71 degrees.
Thinking my thermostat was confused, I overrode the setting controls and turned off the air conditioner from the thermostat. But that action turned off only the blower fan and I could still hear the condenser fan running so I manually tripped the corresponding circuit breaker (dedicated to my heating and cooling system) and went back to bed.
Next morning, I switched on the circuit breaker again and hearing nothing, turned on my AC from the thermostat. It seemed to work fine all day but at the end of the day, the condenser fan had a mind of its own so cut the power off to the entire AC system again.
I called several HVAC places and they all wanted $300+ just to come out and take a look. For that kind of money, I thought I’d try to troubleshoot myself first.
REQUIRED PARTS / TOOLS
- Socket + Ratchet
- Can of compressed air (I use Dust-Off Compressed Gas Duster – 4 Pack – DPSXL4)
- Plastic coffee stirrer (get some at 7-Eleven or QuikcChek) in case your air can nozzle breaks off
- Pancake Compressor
ALLTHUMBS DIY – WHAT I DID
Based on the fact that my thermostat was able to control the blower fan, I guessed the problem was caused either by tan HVAC controller unit (located in the blower fan unit) or from s failed component inside the condenser.
If you are interested in learning about HVAC condenser component names, Inspectapedia.com has an excellent article.
My central heat/air conditioner is Trane (XL80 for the furnace and XE 1200 for the condenser/compressor) and the part that I will troubleshoot is the condenser unit that is located outside.
Step 1 – Turned off the circuit breaker at the main panel
Step 2– Removed the quick disconnect connector
Step 3 – Removed the access panel on the condenser unit
Step 4 – Removed the cover panel inside the condenser unit
Step 5 – Take a can of compressed air and blow out all debris. Most air cans come with a skinny but sturdy plastic nozzle that can get into small crevices. DO NOT USE compressed air from a a pancake compressor as the air from it is TOO strong.
Step 6 – Make sure to blow out dust and other particles between contactor plates by using the plastic nozzle because a contactor’s CLOSED or OPEN position turns on or off the condenser.
Step 7 – While the panel is removed, check the metal cooling fins and remove large debris as well as any accumulated dirt on the bottom. I used my Porter Cable pancake compressor for this purpose.
Most times when I am troubleshooting, I get very frustrated because it’s like opening a can of worms. But this time, I got lucky because simple cleaning solved my problem.
I will be posting a follow up article when I replace the contactor and two capacitors soon.
Well that’s it for this part of the article. I hope it helped you at least a little bit in solving your Trane condenser/compressor problem.
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Thanks and good luck!
11 thoughts on “Troubleshooting a Condenser Fan That Will Not Turn Off”
Soooo, just blowing out the debris unlatched the relay? Wow, very doubtful from here… Good luck with your next “Mr. Fix it Project”!
Who knows, maybe when I was taking off the cover, something jarred loose or I just got lucky?
Since these relays are cheap, I will probably just replace it in spring.
Did you have a similar problem with your condenser?
THANKS TO THIS THREAD ON DIY, I JUST FIXED MY TRANE 1200 AIR CONDITIONER. I AM A 53 YEAR OLD, FEMALE BANKER AND RECENTLY DIVORCED! NO MONEY FOR REPAIRS. I REPLACE THE CAPACITOR AND RESET THE CONTRACTOR! I FEEL LIKE I CAN DO ANYTHING NOW. THIS ISN’T THE FIRST TIME I HAVE MADE REPAIRS THROUGH THE INSTRUCTIONS ON DIY AND I REALLY LOVE THIS SITE. THANK YOU!
awesome! thank you for your kind words. I hope to provide more useful content in the near future…
should power or phase should be on L1 and L2 and nothing else. That T1 and T2 will have the other end power for fan and compressor?
I think you need to first read the support manual for your thermostat control to figure that out.
What Brand js that fuse box, I am looking for the disconnect tab and there is no label anywhere on the box
Mine is Cutler Hammer (Eaton) DP0222R which is no longer made. I think the newest equivalent model is DPU222R (product link here). According to reviews, this newer model also comes with a pullout disconnect. For safety reasons, I would personally NOT interchange disconnect tabs, even for similar models.
How did the banker lady replace the capacitor with instructions from this DIY? I don’t recall seeing that.
you are correct, i do not have instructions on replacing the capacitors. fortunately or unfortunately, i will have to replace them, as well as the contactor relay, so i will post my results soon!
Hi everybody, I have this weird case where the condenser unit fan won’t shut off running when the night comes this right about 9pm I have to be checking outside so that the fan wont run for long periods of time and I have to pull out the disconnect from the box to shut it down then power it back on from the thermostat again and also will do it the same if it rains at any time of the day. my system the infamous Rheem 3 ton 2 stage UARL-036JEZ from 2010 I bought it new back in 2018 so is just 4 years used, if anybody has some ideas or have come across with this issue let me know what steps you took to solved.