Air Conditioning & Heat Pump Compressor / Condenser Fan or Fan Motor Repair FAQs

Condenser fan won't start, stop, or won't keep runing

Condenser Fan Wiring FAQs

Reader question: Pioneer heat pump fan reversed direction

I'm new to heating and cooling. Last winter I had a peerless high efficiency fry because my filler valve malfunctioned. I ended up replacing with a Navian high efficiency boiler.

Was... interesting to learn. Since then, I bought a mini split pioneer seer 19? I think it is a 13k btu unit.

I installed it following the install instructions to the letter.

I got everything hooked up and my buddy lent me his evacuator. I dried the lines and did the pressure testing and all held perfectly. I then opened the service valve port to charge the line set with freon (whatever the new stuff is called).

I could hear the lines charging and again, no leaks.

The gauges were around 270 (according to my buddy as he read the numbers to me) or so while trying to cool.

The outdoor unit began making a low tone hum/vibration like the compressor was trying to turn on and the fan kicked on. Nothing. No cooling, no heating.

The line sets didn't even get cold or hot by even a degree difference. The reversing valve must be working (im guessing) because when i call for heat, the fan will come to a stop, pause and then reverse direction.

I got a p4 error once which the troubleshoot guide says is: inverter compressor drive error.

I have not got that error since. Any idea what this could be? Is it just as simple as the compressor drive error? Is the drive separate from the compressor? On 2020-09-09 by Bobrosss

Mod reply:

Bob,

Thank you for the helpful diagnostic question about your Pioneer brand Mini Split AC unit. The fact that your fan is reversing direction tells me that this is a heat pump and the controls are miswired or oscillating between heating and cooling, or there's a fan wiring error - as the unit's new.

More subtle would be a mis-adjusted or debris-clogged expansion valve or reversing valve.

Note that Pioneer's mini split units come pre-charged with R410A in a volume sufficient to ccommodate refrigerant line lengths up to 25 ft. per circuit. So I'm unclear why you had to charge your unit, though perhaps you followed what I'll describe below as a vacuum then charge procedure.

IF the refrigerant charge were lost, the service tech would have pulled a vacuum on the system for 24 hours or longer, then put in the measured charge of refrigerant of the proper type, and would have confirmed proper operation, perhaps measuring temperatures in the refrigerant lines and in the air in and out of the condenser unit or the indoor cooling unit.

Below is an example - for other readers, of a Pioneer mini-split AC system.

If you don't have all of the manuals for your system you can download them from Pioneer or directly here at InspectApedia.com at

PIONEER HVAC MANUALS Air Conditioners, Heat Pumps, Split Systems, Inverters

I'd contact Pioneer directly at their tech support department to ask for further help with that P4 error.

Contact Pioneer at (800) 919-0150 Web: pioneerminisplit.com/

Reader follow up:

Yes, I am not familiar with the proper terms. I did the vacuum and charge thing, meaning I hooked an evacuator pump on the system and then just opened the service valve so the R410a could fill the line set. Thank you for your response. I will contact pioneer. ugh, I mean I did those 2 tasks separately hehe.

Reply:

Bob:

I would leave the system OFF entirely until at the very least you're sure that you put in the proper charge of refrigerant. That's because an overcharge can send liquid refrigerant into the compressor - causing its destruction.

 

Reader question: fan is blowing hot air out the sides

I had a new comparator and fan motor put on my Trane compressors/condenser outside. The fan is blowing hot air out the sides and you feel cool air on top Is it running in the right direction On 2020-07-22 by Joanne

Mod reply:

Joanne

On most units that would be backwards

New fan motor gets very hot and stalls - wrong horsepower or fusing or capacitor?

Air conditioner guy changed the fan motor on compressor, and it's getting very hot to where it starting to burn up and stall, I looked at it and it's a 3/4 hp instead of a 1/3hp and a 5.2A I stead of a 5.0A, he also deleted a little transformer and added 2 different capacitors, so is that the problem? On 2021-07-24 by TJ

Reply by inspectapedia.com.moderator

@TJ,

I don't feel safe diagnosing this one from your text alone, but it certainly sounds like there's a wiring error if not a couple of errors.

You might want to call the service manager and ask for an experienced service tech.

In the meantime you want to leave that system turned off to avoid fire.

 

York YCJF42541S1A outside unit was running but the fan blades weren't

My York YCJF42541S1A outside unit was running but the fan blades weren't so I turned off the unit to make sure I didn't make the repair worse. Inside the house is warm and could have been blowing warm air. Tech came out and replaced the fan motor.

Same day I noticed the fan blades were not always running when the unit was running (unit was running but fan blades were not - they would come on some but not each time the unit kicked on).

Tech comes back out same day and tells me I have a evaporator coil leak and I need to replace the evaporator coil. Does this seem reasonable? The unit is 8 years old. Shouldn't the coil last longer than that? I don't want to spend the money if it is a capacitor. Help 2020-06-08 by Denise

Mod reply:

Denise

There is probably something here that we don't understand. I'm not sure how refrigerant leak would make the fan run intermittently.

Seems more likely that it's a wiring or control board or motor capacitor problem there may also be a refrigerant leak and which case we would have The Coincidence of two different problems occurring at the same time.

Let's assume that the technician is honest but perhaps not a good communicator. You might ask for an explanation and let me know what you're told.

Follow up:

Ok, I am not sure about the model number of my unit either. The tech's writing is hard to read. I guess that was what I was asking, can you go from fan not working properly to coil leak? I am not convinced the fan was fixed either the first or second visit.

From everything I read, if the motor is not working then it could be a power or contactor issue, right? The unit cooled fine until late last week when we noticed it being extra warm but we have had a mild spring until the last couple of weeks.

I am thinking of asking for a second opinion just to be sure before I sink money into a new coil. Anything else you can think of to ask about this situation? I really appreciate your help!

Condenser fan wiring nicked by a fan blade

Wire of my AC outside the house has been knicked by the fan. AC does not work. How to repair the damage. Thanks. (June 16, 2014) Nick

Reply:

Nick

If the wire didn't short out (which would damage equipment or trip a breaker) it can be spliced & waterproof-taped, or replaced completely.

WATCH OUT: for fatal shock hazards. Don't try working on live equipment. Hire a trained professional if you are not qualified to make this repair.

 

Refrigeration condenser unit fan not working - changed from 12V to 220V fan motor

I have a Samsung refrigerator model RS22FLMR that has a problem.

First the condenser fan (12 volts) is not working I replaced but it is still not working ,

I replaced it with a 220 volt fan. It works good but the compressor started once when I powered the refrigerator on then it would not start again until I un-pluged and re-pluged in the power cable

What should I do?

Is it because of DC 12 V fan not connected to board so compressor wont start again? or board problem or what u think about that . - On 2019-05-21 by Farid -

Reply by (mod) - high head pressure: compressor can't start

Farid

When a compressor motor has trouble starting in the manner you describe I suspect a refrigerant metering device clog - such as a clogged cap tube.

If the compressor is facing high head pressure on its outlet side it can have trouble starting.

Watch out: I'm very concerned about your switching fan motor types going from 12V to 220V. Start by reviewing the manual and wiring diagram for your Samsun refrigerator. I'm doubtful that you can simply change a fan or fan motor between those voltages.

For example, if controls in a refrigerator expect to be switching on and off a 12-Volt motor, they may not work with a 220V motor, and worse you could be risking shock or an electrical fire.

Compressor / condenser unit fan wiring: the hvac tech left wires sticking up out of my fan unit

I just had a new fan motor installed....$569.98! Also is it standard procedure to have wires sticking up from the top,,,,? These were told to me to be so he could reverse the motor if need be? - Vicky Cummins 6/18/12

I have a red and white wire coming into my house for the thermostat from the AC unit. in the furnace I have red, white, green and yellow. which wires should I connect the red and white wires from the air conditioner to? (Apr 28, 2015) Anonymous

Reply:

Vicky,

No not in my opinion. It is a poor and dangerous practice to leave live electrical wires protruding out of any appliance - it's a shock and electrocution hazard. Perhaps the tech intended this as a temporary measure to be sure s/he could correct a wiring error. But electrical wires should not be left exposed.

Anon: see

THERMOSTAT WIRING COLOR CODES

at inspectapedia.com/heat/Thermostat-Wire-Color-Codes.php

New condenser fan motor, cap, but compressor hums

Condenser fan motor, new, all capacitors, new, Works fine cools house for 1/2 hour then new fan motor shuts off and compresses hums, wait 1/2 hour and it does it all over again. help - Mike Nichols 5/2/12

my unit outside will not come on but it does inside what can be wrong - Larry 5/21/12

Reply:

Mike it sounds as if you are describing a bad compressor motor, bad starting capacitor, or wiring error, not a bad condenser unit fan motor, especially if you are dead certain the start/run caps are OK.

See COMPRESSOR / CONDENSER REPAIR where we list diagnostic articles.

Larry: same advice as for Mike. If you are sure the controls are calling for the equipment to run and voltage is present, start by checking the diagnostic articles in the order listed at LOST COOLING CAPACITY.

 

Question: risks associated with running the inside and outside A/C units to the same electrical line?

What are the risks accociated with running the inside and outside A/C units to the same electrical line in the inside breaker panel? Just had an older unit replaced by a new 3.5 ton inside air handler and outside condenser. Thanks. On 2020-08-31 by Andrew R.

Reply:

Electrical overload, loss of cooling.

 

Heat pump fan outside is not working after water leaks

My heat pump fan outside is not working after a man put a water pump in the roof before he came water run down the wall in side. 2020-01-25 by joyce

Reply:

Joyce

From the very little we know about that situation that you described it would make sense to leave the circuit off completely for safety. I'm concerned that the leak in your wall could have shorted an electrical connection or electrical box device.

 

 

Compressor / Condenser Unit Fan Runs Backwards FAQs

These questions and answers pertain to the outdoor air conditioner or heat pump compressor/condenser unit fan and fan motor.

If your concern is the rotation direction of the indoor air handler or split system indoor blower unit fan see AIR HANDLER / BLOWER FAN RUNS BACKWARDS FAQs

Condenser Unit Fan Motor Runs Backwards

Older Bryant A/C. The condenser fan finally failed. Found a replacement Motor and Capacitor from NA and installed. Motor fan is running backwards (pulling air in top, thru the coils and out the sides.

Motor was equipped with stacons on the orange and yellow wires and you are supposed to disconnect them and connect both orange to yellow to reverse rotation. Reversed wires, still rotates the same direction.

The capacitor is a 3 wire (one each end, one in middle). Installed the cap in same orientation. Tried swapping the power leads (black/white), motor wouldnt turn (just a brief pulse, sounded like a 3 phase motor being single phased), switched them back.

The Cap is an exact replacement, but should I try putting the old one in? Motor-Emerson K55HXSSM-7146, Cap is a Cera-Mite 305CIS 5uf... Thanks 2018-08-08 by JJ Smith

Mod reply:

When a fan runs backwards it's mis-wired (or has been struck by lightning); It sounds as if you are perfectly on top of the wiring directions to reverse fan direction.

If that's not working but the fan ran fine in the wrong direction I don't suspect the capacitor I suspect a wiring error such as an inadvertent short or internal damage in the motor. Sure it won't hurt to try the old cap.

See the diagnosis and repair advice

at ELECTRIC MOTOR RUN DIRECTION 

Watch out: as you may know, making a mistake can shock you or kill you.

Can a condenser fan running backwards cause evap coil to freeze?

Can a condenser fan running backwards cause evap coil to freeze up? 2017-08-08 by Anonymous

Mod reply: condenser unit fan runs backwards?

Anon:

If a backwards running fan means that the proper CFM of air flow across a coil does not occur, in a CONDENSER in cooling mode (air conditioning mode if it's a heat pump) then the condenser will be too hot, the high pressure gas will not adequately cool to liquid form, but none of that would cause icing of the outdoor coil.

An indoor evaporator coil will freeze up if air flow is reduced or cut off for any reason: backwards fan or dirt or dirty filter.

See the diagnosis and repair advice found

at ELECTRIC MOTOR RUN DIRECTION

Condenser Unit Fan Speed FAQs

Helpful diagnostics

• CONDENSER FAN RUNS SLOWLY

Slow Condenser Fan Problem Diagnosis & Repair

I have had this problem with my AC unit for some years now. techs have been out several times for free inspections, and nobody seems to see anything wrong other then try to sell me a new unit.

That costs $1000's. So here is the weird thing. When the condenser fan started to go out slowly but surely, for some reason the AC was working better then ever!

Cooled on the hottest days. I know the condenser fan was running slower until the tech came to replace it.

But now that he replaced it, here we are again with warm air. Or shall I say cool air, but not really cold.

Someone told me maybe the RPM rating of the condenser fan is too high, and over cooling the coils. I never heard of that. Or theoretically how is this possible?

But one tech guy told me that the outside condenser coils needed to get warm enough for efficient cooling to occur.

Over cooling them won't allow the exchange to happen properly. Is this why we have been living with the cooling efficiency AC unit? On 2012-06-17 by Anon

Reply by (mod) - Condenser RPM and Condensing coil warmth - Illogical claims?

Condenser RPM question:

Thanks that's an interesting question and not a hypothesis I've come across. At least part of it makes no sense to me whatsoever, in particular, and reading your comment to refer to the outdoor condenser FAN unit not the compressor motor itself:

"But one tech guy told me that the outside condenser coils needed to get warm enough for efficient cooling to occur."

Think about what is happening in the outdoor compressor/condenser unit: the compressor condenses low pressure refrigerant gas into a high pressure high temperature refrigerant gas. That high pressure high temp gas enters the condensing coil.

The outdoor fan blowing air across the coil transfers the heat of the high temp high pressure gas to outdoor air, AND in the process condenses the gas back to a liquid refrigerant that is then sent over to the indoor cooling coil.

Making the outdoor condensing coil hotter would not improve its performance, it would harm it, in general.

There could be something else, odd, going on, and it doesn't sound as if you've had a clear onsite diagnosis.

Some fans can run at more than one speed or even variable - but usually at the indoor air handler not the outdoor unit.

A bad motor, voltage, or control can cause the outdoor condensing fan to run at the wrong speed however.

It may be worth looking further for a problem with refrigerant metering equipment at the indoor air handler/cooling coil, or the system could have an improper quantity of refrigerant charge;

I am SPECULATING that artificially slowing the delivery of liquid refrigerant back into the indoor equipment (slow outdoor condenser processing) might mask an indoor refriterant metering problem. Keep us posted, what you learn will certainly help others.

 

Outside condenser fan funs slowly

The outside motor fan funs slowly but all the time ( even though the thermostat is off) and the a/c unit will not turn on when the thermostat is turned on - the compressor sounds like it is starting, but 30 seconds later it sounds as if it is bogging down, then shuts off.

Any ideas? Thanks On 2012-05-01 by Mike

by (mod) -

Slow fan could be a bad start capacitor or a bad motor run capacitor.

See our diagnosis and repair advice

at CONDENSER FAN RUNS SLOWLY

Condenser unit fan spins too slowly after I replaced the condenser motor and capacitor

I replaced the condenser motor and capacitor; now the fan spins slow what could be causing this. 2018-08-17 by valleyworld25

Mod reply:

VW

Some possibilities include a loose connection, a bad capacitor or wrong value capacitor, for the fan motor (not the condenser motor), low voltage, or fa ailing fan motor.

Less likely a loose fan blade

Condenser Unit Fan Won't Keep Running FAQs

Also see these related COMPRESSOR / CONDENSER UNIT FAN WON'T START, WON'T RUN FAQs

Reader question: AC turns off outside and doesn't come back on until I switch the AC off

My heat pump has a similar issue only in reverse. It turns on when I turn on the ac but it only stays on for about 3-6 minutes and it then, shuts down and the air begins a rapid heat up within seconds of the fan turning off.

The fan turns off outside and doesn't come back on until I switch the ac off and wait at least an hour or so n but it is still blowing air in the apartment. 2020-07-13 by Jon Christian

Mod reply:

Jon

I think you are describing the case in which the outdoor compressor condenser unit is shutting down shortly after startup. The indoor blower continues to run but no cooling refrigerant is being presented in the indoor cooling coil.

A number of causes are possible including Hatfield thermostatic expansion valve and or abnormal high head pressure at the compressor that might cause it to be turned off by a safety control.

Do let me know what your service repair technician says

Fan on outside condenser unit stops running

My Unit is cooling fine except sometimes the fan on the outside unit will stop.

I can cut the thermostat off and back on and it will run. sometimes it runs for 2-8 hours before cutting off.

Any ideas what is going on? On 2012-05-04 by fan on

by (mod) -

Fan unit stops: You are describing a problem with the cooling fan on the outdoor condenser/compressor unit of an A/C system. If the fan motor is not running or won't keep running I'd check for a bad start/run capacitor or a bad fan relay.

Other fan troubles include a loose wire, or a worn fan motor shaft bushing that is binding (see if the blades spin freely when power is OFF), or a bad fan motor (binding or overheating).

Air conditioner runs for a couple of hours then the condenser fan will suddenly stop

I have a nordyne model js3bd-030k that after been running for couple of hours the fan will suddenly stop even when you still feel the air circulating and out of the vents any body would know what is causing the fun to act this way any help will be greatly appreciated. thanks for any help

Reply:

Mario, the air conditioner or heat pump diagnostics on this page apply to the outdoor fan found on the condensing unit.

But as you are talking about stoppage of air coming out of your indoor supply registers, you will want to take a look at the diagnostic notes on the indoor air handler or blower fans (the indoor unit that circulates air in the building) -

see BLOWER FAN OPERATION & TESTING.

 

Question: Compressor / Condenser fan stops working in hot weather - replacement motor also failed

I have an ongoing problem with my A/C unit. It is working until it gets very hot (over 100 degress here in Texas) and stop blow the cold air.

I called a tech last year and he replaced the fan motor twice, once with a same model and next with a larger fan. Again this year I'm having the same problem. Any idea what could be the soulation? - Abby

Abby I am having this problem and I can wait untill the late evening when the temp drops or the unit becomes shaded I can reset a swithch and it turns it back on and it will blow cool air untill the next day when it does the same again. I suspect it is the overheat switch because mine is always popped - Ernie

Reply:

If a fan motor is replaced repeatedly I'd ask the service tech and service manager to do some further investigating as something else may be destroying the fan motor.

Examples of other problems that can ruin the blower fan or condenser fan motor include:

- an improperly-sized start/run capacitor that fails to drop the start capacitor out of the circuit once the fan is running can burn up the fan motor start windings

- consistent abnormally low supply voltage

- a mechanical problem stressing the motor such as a blower assembly bearing or shaft problem or improper fan/blower connections or mounting

Condenser/Compressor fan gets very hot and won't keep running

compressor fan motor was vary hot and not running turned off system and let it cool down turned it back on and the fan motor would not start just got hot quick to the touch could the fan motor be shot or could it be something else? On 2011-07-28 by awisewon

by (mod) -

Awisewon

if the fan motor is very hot it sounds like an overheat condition - the motor might go off on thermal reset, it may need replacement; the fan motor and compressor motor are physically independent, though even a compressor that runs normally might heat up and shut down if it's partner, the condenser fan, does not run.

When you turned off the system and let it cool and the fan wouldn't start, and the fan motor got hot, that's a compelling indicator of either a bad fan motor or a bad start/run capacitor.

Heat pump is not blowing cool air - the condenser fan won't keep running

have a heat pump not blowing cool air. The condensor fan will run for about 1 minute then shut off and not start again for a few mins.

Once it starts up the same thing every time. This unit says it should be at 300 psig for both high and low pressure but when i put the gauges on it im only getting 155 on both sides. what could be causing this.

I suspect that the unit has a low charge and is causing the fan to trip or the compressor may not be pumping, im not sure. all i know is that when my gauges are on it they do not change in pressure when i engage the contactor - Cox HVAC 5/26/12

Reply:

Your system compressor is not continuing to run, nor is the fan. Check the start/run cap and the control board as well as the relay.

Question: Common causes of a fan motor intermittently cutting off

I have a trane heat pump. The fan motor and capacitor have been replaced.

The fan is still cutting off and not cutting back on. Got up this morning and it was off, but the unit was still running. It had gotten down to 62 degrees. Had to turn the unit off for about an hour. When I turned it back on the fan came on. What else could be wrong with it? 2019-11-25 by Chris

Reply:

Chris

Common causes of a fan motor intermittently cutting off include

- loose or bad electrical connection

- defective fan control relay or control board

- overloaded motor, including possibly low voltage supply that could affect even a new motor

- improper installation, binding motor or fan assembly (also overloading the motor)

You might also find by searching this website our article on ELECTRIC MOTOR DIAGNOSIS

Question: condenser fan will run for a few hours and then stop

My condenser fan will run for a few hours and then stop. It runs and starts intermittently. When it stops there is a buzzing noise coming from the unit. The capacitor has been changed. Does this mean the motor is bad? 2019-06-04 by Caleb

Moderator reply:

Quite possibly or a bad starter relay or bad electrical connection or low voltage

Question: fairly new heat pump will run well for 5 hours then shut off and not do anything

our fairly new heat pump will turn on and run well for 5 hours. Then it will shut off and not do anything. If kept off or on for several days, it will come on without notice or necessary need. It has been doing that for 7 years. always think it is broke, but it will start working for 5 hours or a month. then it will shut of for maybe 3 or 7 days and do it again. have had HVAC people check it. nothing fixes it. 2019-04-20 by hey

Reply:

Hey Hey, I"m just guessing but if the compressor motor (or fan motor) is overheating it may be shutting down on thermal overload; when the motor cools off it will re-start.

It's time to ask for some diagnostic help from a trained service tech; she might include measuring the current draw of the motors for signs of excessive draw - a sign of a failing motor or bearing (or other problems), as well as checking for a sticking refrigerant metering valve and high head pressures.

Follow up:

It could be over heating. But, i can reset everything. And wait. It might come back on in 5 minutes. Or it might not come back on in 7 days. it does not matter if the unit has been setting for many days after shutting off. For example it shut off about 5 days ago. I reset everything that I could reset. circuit breaker etc.

And it came back on 1 day ago. it was about 60 degrees outside and 73 degrees inside. it just came on. It can do that when it is very hot outside or cold. It will run fine even on pleasant days. But it will just shut off. And it might not start running, the fan running and everything, for 1 to 14 days. it is as if it has a mind of its own. I have called people out to check on it. And nothing. it works. Then does the same thing. it has been happening for years now.

Reply:

I guess if a thorough review of all of the connectors does not find a loose or corroded connection and we are looking at a bad control board or relay

Condenser Fan Won't Stop FAQs

Moved to

CONDENSER FAN WON'T STOP RUNNING FAQs

Condenser Unit Fan Won't Start FAQs

Moved to

COMPRESSOR / CONDENSER UNIT FAN WON'T START or WON'T RUN