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Photograph of the outdoor safety switch for an air conditioning residential systemAir Conditioning & Heat Pump Controls FAQs 3

  • POST a QUESTION or COMMENT about how to find, identify, & use or troubleshoot each control or switch found on air conditioners or heat pumps.

HVAC system control & switch Questions & Answers:

This article series explains where to find and how to use the switches and controls for air conditioning and heat pump systems.

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Air Conditioner Switch & Control FAQs

A/C Compressor control board © D Friedman at InspectApedia.com These questions and answers abour air conditioner and heat pump controls and switches were posted originally at CONTROLS & SWITCHES, A/C - HEAT PUMP where you will find a discussion of thermostats, zone dampers, and circuit breakers on air conditioners and heat pump systems.

Air conditioning and heat pump diagnostic procedures are at DIAGNOSTIC GUIDE A/C or HEAT PUMP

First here are some helpful A/C and heat pump diagnostic procedures:

If your air conditioning or heat pump system has lost its cooling capacity or won't start select one or more of the diagnostic articles listed below.


On 2013-01-25 by Cool Air

the reansing that you condenser want shut down is because your contactor points are stuck!!

On 2012-12-26 by pedro c.

Mike e it sounds like the contactor is going out, look at the copper where the button pulls and if the contactor is burned and pitted then it is time to replace.

On 2012-12-16 by Dave

II have a 1994 2 1/2 ton ac split unit. Problem is room gets to proper temp compressor shots down(but compressor fan stays on cold air). GGo upstairs raise thermstate till click then lower till activates compressor. within minutes room is cool.

I have replaced hard start capacitor,run capacitor, tried a spp6 hard start on run capacitor(foolish). I realy don't want to change out the rly1097 start relay if some one has a solution. The AC unit worksperfect when running.

On 2012-10-08 by Angie

I have central air conditioner, with an old box up and down switch, does it go up to turn off compressor for fall or down?

On 2012-09-07 by corky

my heat pump stopped cooling , upon inspection I found that : in cooling mode inside fan runs, outside compressor and fan won't start(obviously why it's not cooling). I switched over to heating mode and all system components work and I get heat. Could the compressor/fan contactor have separate relay for heat and cold?

On 2012-09-07 by Anonymous

my heat pump

On 2012-08-18 by mike e

I have a York 4 Ton 3 Phase Heat pump unit thats giving me problems. The board is getting 24v.

The High pressure switchs are fine. When I short the test switch together the contactor relay just for the fan buzzes for a few seconds(like its going in and out) then stops and nothing starts up. I can push in the compressor contactor manually and both the fan and compressor come on.

The board is not sending 24v to the compressor contactor when i short the test switch together. Any ideas on this would be helpful?

I've already changed the 5X440 capacitor, The fan relay. The low pressure and high pressure switches are closed the thermostat is calling for cool, the fan relay is getting 24v and the reversing valve is not stuck.

On 2012-08-15 by Anonymous

my panasonic wall mounted air conditioner turns on and partially cools the room but the compressor shuts down before it cools down the room to 70 degrees. Is it the compressor the unit's thermostat, the compressor or ahould I buy a new unit and chuck the old one?

On 2012-07-18 by (mod) -

Bobcat, thanks for helping out.

Tim:

regarding "I have an outside unit that wont shut off without tripping the breaker. A friend suspected the thermostat so I replaced it, but it didnt solve the problem. Any suggestions? The inside fan kickc on and off within the set temp range, the outside motor just keeps going."

- if the indoor air temp never reaches the set temp on the thermostat the system will just keep running - so if that's the case we need to determine why the indoor cooling isn't satisfying the thermostat.

- if you turn the thermostat setting "up" to be sure that the indoor air temp is below the set temp on the cooling thermostat - that is, the thermostat is satisfied, and then if the equipment still never stops running, I suspect a bad control board or relay switch - and it's certainly time to call an HVAC/R service tech.

On 2012-07-18 by Chris B.

This is a straight AC unit. Yeah, I should have checked the 24 volt. I will do that. I appreciate any help I can get here.

On 2012-07-18 by Anonymous

This is straight AC with control that runs to the furnace

On 2012-07-18 by Bobcat

To: Tim B

Is this a heat Pump or Straight AC? A heat Pump uses a circut board to control the outside fan, and a straight AC should operate the fan when ever the compressor runs( cooling ).I will try to help

Chris B. Is the condensing unit you refering to, a heat pump or straight AC. Either way you will need to measure voltage at the thermostat wires that attach inside the outdoor unit.

On 2012-07-17 by Tim

I have an outside unit that wont shut off without tripping the breaker. A friend suspected the thermostat so I replaced it, but it didnt solve the problem. Any suggestions?

The inside fan kickc on and off within the set temp range, the outside motor just keeps going. Thanks for any help.

On 2012-07-17 by Chris Bauer

The unit won't start at all. I get 236.4 VAC coming in on the line, but the relay won't latch. So, I went and bought a new relay and replaced with not luck.

I then used the manual push button on the relay to latch the connection and heard a light hum. I then gave the fan blade a little help and it started turrning. However, it did not get up to speed and the compressor never kicked on. The relay won't stay latched regardless. Any ideas for me here?

On 2012-07-12 by Wallace

Actions that start ac are; repeated tripping of thermostat or tap on inside unit's control box which houses fan switch and heat/cool switch.

Tap starts system every time. System is a 1976 Coleman Presidential 2 split unit in a mobile home. When this fault occurs, the familiar hum of the inside unit is not heard. Once system is started, it performs well and cycles off as desired. Fault occurs 75% of the time. Thanks.

On 2012-07-11 by mary

my electric furnace the inside unit the fan runs all the time even if we shut the thirmasat of what would cause that.

On 2012-07-07 by JK

How much is a 240/24 vac contactor and a run start cap installed?

On 2012-06-26 by (mod) -

El: I'd have someone check the thermostat wiring -

On 2012-06-26 by (mod) -

Josh, I suspect you'd be better served calling an expericenced hvac tech. The low voltage transformer is visible in some of our fan limit photos found at FURNACE CONTROLS & SWITCHES - (search InspectAPedia for that title)

On 2012-06-26 by EL

Hi. For some reason, our dual zone unit keeps cooling the downstairs zone to well below the set temperature -- when set at 79, very cold air is still blowing though the thermostat reads 71. Cold air still blows even with both thermostats turned to "OFF."

Not sure what is causing this, but I am sure it's gonna cost me $700/month if I can't get the air to shut off.

Any thoughts would be greatly appreciated!

On 2012-06-22 by Josh

So, by following and replacing the thermostat wire from the outdoor ac unit into the attic blower, I will find a low voltage transformer that powers the thermostats throughout my house, correct? What would the low voltage transformer look like? Could it be a fuse like I would find in a car?

On 2012-06-21 by (mod) -

Josh, usually the thermostat is powered by a low-voltage transformer - you need to find it and start tracing wiring there to find where the system has either lost power or has a broken or shorted wire.

And of course, if power is off to your equipment, then power is probably off to the transformer too.

On 2012-06-21 19:27:26.594133 by Josh Massih

Hey MODs, I got a quick question and would appreciate any help or information.

I clipped the thermostat wire to my central AC unit outdoors, and the power to both the main blower in the attic and outdoor AC unit will no longer start. I spliced the thermostat wire back together and replaced the contactor on the outdoor AC unit in hope that it would fix the problem

. However it did not. I have tested for a current on the contactor in outdoor AC unit and it's there, but there is no current in the thermostat wire leading up my house and into the attic. When I test for current in the thermostats located throughout the house there is also no current. What would be the next move?

I plan on going into the attic where the blower is and replacing the entire thermostat wire leading to the outside AC unit and checking for a burnt fuse in the circuit.

There wasn't a reset button on either appliance that I could find, only a transformer switch outdoors near the AC unit and a "AC on / off" switch in the attic. Any suggestions from this point would be appreciated. Thanks

On 2012-06-20 1 by (mod) -

AC keeps running:

RE: a thermostat reading the "wrong" temperature, a bad battery doesn't change the temp reading in my experience, but it'd be trivial to try a new battery if that's needed - you must be talking about a remote control unit since wall thermostats, even though they may use a backup battery, get their normal power from a low voltage transformer.

And "it feels like 70 but the the thermostat reads 60" is an understandable point of confusion. The thermostat is measuring air temperature just at the wall where it's mounted. You may be feeling air elsewhere in the room.

Finally, if your unit is not working properly or is oversized and thus is not dehumidifying, the room may be uncomfortable (and too humid).

On 2012-06-20 by (mod) -

Marty, your A/C guy is very busy and has some clients who pay well enough that he doesn't want to work for you. Call someone else. It sounds as if you may have a cooling coil that becomes blocked by frost or ice - possibly a dirty air filter or a low refrigerant charge. Let us know what a (better) HVAC tech finds - it will assist other readers.

On 2012-06-19 by Marty

My air condition will start blowing air and start cooling off but in about half an hour or so, the air starts to diminished and eventually gone. I called the air condition repair man and he said nothing is wrong with my air condition.
Please help.

On 2012-06-15 by ac keeps running

my ac runs for two to three hours and the house is cool but wg=hen i look at the temp on my ac its says it 80 degrees when it feels like 70? could it be the battery?

On 2012-05-07 by (mod) -

Anon: regarding a burning odor from the indoor A/C air handler unit: you should TURN OFF AND NOT RUN the equipment until the problem is diagnosed. You are asking for a house fire. When the trou7ble is diagnosed you'll know if it's something trivial like a worn shorting wire, or more costly like a fan motor.

On 2012-05-07 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).

On 2012-05-05 01:23:30.696116 by Anonymous

We have a burning smell coming from the vents. The AC has been on for one full day. We have been told that the unit is too big for our home. Is there any way to keep whatever motor that is overheating from doing so without buying a brand new unit?

On 2012-05-04 by fan on outside unit stop

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 2012-05-01 by (mod) -

Slow fan could be a bad start capacitor. Search InspectApedia for "condenser fan runs slowly" for a helpful diagnostic article that discusses this problem.

On 2012-05-01 by Mike

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 2012-04-20 by (mod) -

Thanks Matt, I agree; a bad capacitor will explain a fan that will run if given a push but won't start on its own. Delona you might want to read about this problem at CAPACITORS for HARD STARTING MOTORS (article links at ).

On 2012-04-18 by Matt

Delona

It's a bad capacitor

On 2012-04-18 by delona allen

do you have any suggestions

On 2012-04-18 by delona allen

outside a.c. fan wont start unless igive it a push

On 2012-03-31 by air handler turns on then off...

My air handler turns on then off....condenser is running while it does this....any suggestions? Is it possibly the thermostat? Tech said it was the motor on AHU but the unit is only 18 months old....any suggestions?

On 2012-03-14 by RickR

My AC Fan/motor stops rotating 30 seconds -to- 1 minute after starting, the motor has been replaced and it continues to do this with the new motor. We will have cool air only for the short time the fan/motor is running and then it is only warm air being blown in the house after it stops rotating

. The fan/motor sounds as if it wants to rotate (getting power) but will not rotate. I can turn it off at the outside power outlet and ruen it on and it will rotate again for the same amount of time as mentioned above.

People (no-professionals) tell me if it has lost or low coolant that it will shut down, but it is not shutting down. It appears as if the fan motor is still trying to rotate the fan blade but not turning and burning up the motor.

It is only an AC problem, the heater works great in the winter so do not believe it is an internal problem inside the house???

Any advice or help?

On 2012-03-11 by (mod) -

Anon, sorry but I don't understand the question. Sounds as if you need an experienced HVAC tech on site.

On 2012-03-10 by Anonymous

I have a problem all way flow up the fuse on control board in unit inside the house after it run few minute.I change the PC board already, but the problem till the same.
How can I fixed ?
Thank you very much any help

On 2012-01-11 by HGODOY2@CHARTER.NET

WELL WRITTEN ARTICLE...............VERY USEFULL..........THANKS

On 2011-10-27 by Kurt

I have a Kelvinator JT5BD-042K that won't start. It is only 4 years old, yet I have had to replace two contactors (contacts were burnt up) in the last 2 years. The one installed now looks ok but the voltage going to it is around 16vac to ground whether I am trying to heat or cool or it is off.

There is 27vac at the transformer in the air handler. The thermostat turns on the air handler fan.I have measured the voltage at the defrost control board (PN 917178A)from each of the wire connectors to ground and the only changes I see in from the Y and O wires which reverse their voltages, C, W2 and R stay the same which are either 17v or 8v to ground.

I know my obvious problem is not enough voltage at the contactor, but I don't know why as I don't know how to figure out where the problem is. Is it not getting the right signal from the thermostat, or from the circuit board in the air handler that all the control wires connect to, or the defrost board that sends the 24v to the contactor?

Any help would be much appreciated.
Thanks!

On 2011-09-20 by John

We have a two year old HVAC. It did not start. So we changed to a new thermostat and it worked two weeks and then AC would not start. So we changed a another new thermostat and it worked another two weeks before the AC would not start again. Any suggestion on where to look for problems? Thanks a lot!

On 2011-09-14 by Jerry

My air conditioner will not start on it's own. I originally had to replace the capacitor (was definetely bad), it still would not start. I was advised on how to jump start by pressing the contacts together, being told that the conductor could be bad. After finding I doulod jump start it, I then replaced the conductor.

That has not cured the problem. I can still jump start it, but it still won't start on it's own. I even went so far as to swap out the thermostat, just in case that was causing the problem. I'm now at a loss, and would like to know other possible problems.

On 2011-09-10 by Mike

I have a one year old A/C unit. We just had major rain for the past three days.

While it was raining last night, the compressor unit outside stopped working. The blower inside works. I checked and tested both the circut breaker in the electric panel inside and pulled out and put in the breaker or fuse outside by the compressor unit.

The compressor will not turn on. I suppose something could have went bad, but something tells me I am mssing a reset button or something. Any Ideas?

On 2011-08-25 by (mod) -

Asim Khan: if your system is just not cooling you might want to see the diagnostic steps suggested at

LOST COOLING CAPACITY (article links at )

On 2011-08-24 by (mod) -

Michael:

If by "Power blinked" you mean you had a power surge or outage, I'd check for a bad capacitor (can make a motor run backwards or fail to start) as well as for a burned up relay switch or control board.

On 2011-08-24 by (mod) -

Asim,

with not a shred of information about your system it would be wild speculation to give very detailed repair advice. But if you take a look at LOST COOLING (article link at ) you'll find a sequence of diagnostic steps that should help you home in on the problem with your cooling system.

On 2011-08-24 by Asim Khan

Fan of the indoor unit is working but but not coolling....I set the the Split on 17C....outdoor is also working...plz help

On 2011-08-24 by Michael Baughman

Power blinked Now at 100+ ambient cond fan blows 75 and dropping. Ceiling vents 120+ on cool. Higher on heat. American standard heat pump w/new comp fan mtr, & capacitor . Works backwards can give gauge readings if needed. I have 20+ years heavy Trk repair and a/c repair.

Some home exp. But not heat pump. Have meters also.
HELP !! 69 days of 100+ degrees in Texas. Gonna be workin all nite. Cooler outside than in house.

On 2011-08-24 by mo

unit breaker(240)keeps triping ,it would run a day or two. have to keep reseting

On 2011-08-23 by Roll

Just fixed the unit. Turns out contactor needed a cleaning. All I did was scrape the contactor of debree and corrosion and it now engages and releases as designed.

...

My AC unit will not turn off without shutting off breaker. 68 inside and AC is set at 74. could this be a stat issue?

On 2011-08-19 by mikeC

Hi,

The air handler blower in my Bryant heat pump system stutters sometimes. It only stutters when the thermostat fan switch is in the "auto" position, and not in the "on" position. That leads me to think the relay on the control board is going bad.

The control board is a HK61EA002 (Carrier/Bryant). Rather than pay for a new board, I thought I might be able to just attach the shovel clips / leads to another similar 24 volt relay and mount it next to the board (or let it hang in its box).

Any idea which relay would be universal in an application like this one? The relay on the board is designed for three leads.

On 2011-08-19 by mike

my central a/c (make is carrier) makes a clicking sound but will not syart or run??

On 2011-08-17 2 by (mod) -

Nick, perhaps the diagnostics at LOST COOLING CAPACITY (Found in INDEX to RELATED ARTICLES at our Continue reading suggestions at the end of this article) will help you a bit if you haven't seen all of those steps.

If you're nevertheless not getting anywhere after all of those more obvious things are checked (like a condensate pan overflow switch that can leave a whole A/C or heat pump system shut down), presuming everything is turned on and there is voltage, etc. the direction of my guesses would be a bad start capacitor or control relay or board.

On 2011-08-17 by nick

P.S. I have replaced the thermostat and the same problem is happening.

a couple of days ago my wife turned the ac off so we could open the windows and when she tried to turn the unit back on, the outdoor ac fan would not come on, the furnace fan would constantly run even if the thermostat was switched to the off position, and i can't even get the heat to work

. I've tried most if not all the suggestions you have offered, but to no avail. (i'm not a HVAC tech so some things i didn't feel i should do.) we had our system repaired in the spring, and surprise it isn't covered under warranty. any help or additional advice would be greatly appreciated.

On 2011-08-14 by (mod) -

LaTonya:

If your A/C is blowing fuses there is a problem, unsafe wiring or equipment that is drawing too much current, which is a sign that it needs diagnosis and repair. Could be costly - a bad compressor - or not so bad - like a device that helps your A/C compressor motor get started.

Tell your repairman you'll call him to the fire when the problem he hasn't fixed finally causes an electrical fire.
Or find another repairman.

The text in the article above on this page lists where to find the controls on your A/C system and includes some photos of what they look like. Your fuses may be in your main electrical panel or the repairman may be referring to local fuses at or even inside the equipment - I don't know.

On 2011-08-13 by LaTonya

My air conditioner keeps blowing fuses according to the repairman, but he never does anything to stop the problem. Where are the fuses in the unit, and why would it keep blowing fuses and/or thermostats.

On 2011-08-09 by (mod) -

Good question, Mark. If the compressor motor has experienced hard-starting, such as trying to restart against head pressure and being unable to do so, it might nevertheless be able to start some time later when you've left the system turned off for an hour or more. During that time the refrigerant pressure on the high and low sides of the system would equalize, falling to a low number, making it easier for the compressor to start.

If that's the problem the motor may be nearing end of life but might get some extra use life if the service tech installs a hard start capacitor to give the motor some extra starting energy.

Another possibility is a control (like a refrigerant metering device) that malfunctioned.

Your service tech can check the start and run current draw on the motor to see if it's within normal bounds per the data tag on the equipment.

On 2011-08-09 by Mark

I have a split unit Heat pump system. Last night I noticed that the house heated up to 82 degrees when the thermosat was set at 75. Th air handler fan was running continuously when set at the auto position on the thermostat. The outside compressor unit was not running.

I checked the condenser pan float switch and the condenser pan was dry. I checked and reset all of the circut breakers for the unit and I cycled the thermostat controls on an off. The airhandler unit fan came on but the compressor did not cycle on. The compressor fan also was not running.

This was at 5:00 am. I then shut the entire system down because the air handler fan is an serious energy hog and there was no need for that to be running if the compressor wasn't working. When I woke this morning at 6:30, I turned the unit back on at the thermostat and went outside to see if maybe the motor contactor wasn't being made.

Miraculously the compressor was now working. My question is , is the an overload condition that would cause the compressor motor to shut down during operation and be able to retart after it has cooled down and how do i check the amperage for that?
thanks

On 2011-08-08 by (mod) -

Frank: sure, if your prior thermostat controlled both heating and cooling the replacement unit needs the same wiring and connections to work properly. But if the TT you had before was ONLY controlling cooling, the new one can usually be made to work.

Philip: if your room temperature is below the thermostat set temperature the A/C system should stop running. Including the fan if the fan is set at AUTO. A fan might nevertheless continue running if at the air handler you have a fan limit switch whose control has been set for continuous fan operation - that might be the case if your air handler also is used for warm air heating.

But if the compressor never turns off and the room is cool and actual temperature is at or below the set temp, then there is a control problem or a thermostat problem. I'd check the TT wiring and if it's correct try swapping out the TT.

On 2011-08-07 by Philip

The thermostat fan is set at “auto”, however the a/c compressor has been running continuously since last night. I have mess around with the thermostat temperature control (set it at high temperature) but still could not turn off the compressor. I have to turn off at the circuit breaker to stop the compressor.

The thermostat was replaced a year ago. The a/c is cooling the house and I notice the coils/pipes are frozen due to the compressor running continuously. So, I believe the a/c is working but for some reason, unable to shutoff the compressor. Any help is appreciated.

On 2011-08-07 by frank

my thermostat has been replaced with one that only has an on and off, and only has heater controls. there is no mention of the airconditioner on it . could that be the reason why the a/c does not work

On 2011-08-06 by (mod) -

Jenny

"...wall thermostat does not come on...." means you've lost power to the equipment. Your thermostat is powered by a low-voltage transformer, usually near or even inside of the HVAC equipment itself. If you nipped one of those wires your TT would be dead.

A second thing to look at is whether you've mounted the filter assembly exactly correctly at re-install. Often there is an electrical safety interlock switch on HVAC equipment compartment doors and covers to keep someone from being injured by moving parts when a cover is removed. Check all of your covers for neat and square installation and check that no one knocked-off a door sensor switch.

On 2011-08-06 by Jenny

I turned off my American Standard air conditioning unit to replace the filter. I unplugged the electrostatic metal frame and changed the filter (like I have for approximately 5 years). When I plugged into the frame, the small indicator light did not come back on and the digital wall thermostat does not come on

. I have checked the circuit breaker in the garage...no problems.

I checked the electrical socket where it is plugged in to see if that worked...no problems. I have called several repairmen and they are not able to help until Monday....It's 112 degrees today and I need help.

On 2011-08-06 by (mod) -

I'm not sure, James, from your description. The thermostat is basically an on-off switch controlled by temperatue. They're pretty simple. If you suspect the TT I'd try first an independent temperature check by placing a thermometer in the same location as the thermostat; and of course you could just try replacing the TT.

But if your A/C system is running continuously and the house temp does not drop accordingly there's probably a problem with the cooling system itself. Use thermometers to make a more objective temperature test.

On 2011-08-06 by James Morgan

I set my ac to 80 and it continues to say 84. My house is not hot or does not feel like 84. My unit stays on. does this sound like a stuck thermostat?

On 2011-08-02 by (mod) -

Jeff this question is beyond my expertise. Certainly if you've replaced the control board and are getting the same error the suggestion is that that part was not the problem (though on occasion we get bad "new" parts too). Is the air handler motor itself intact? Did anyone check or replace a start/run capacitor?

On 2011-08-02 by jeff

i have a goodman variable speed air handler that the motor wont ramp up. the red & green light on the top board will not come on either. both boards were replaced same result.i have 24 volts going in and only 13 volts coming out.

On 2011-07-30 by cycle boad

cycle boad lossing 24 volts

On 2011-07-28 by (mod) -

For an air conditioning system that just won't start in response to setting the thermostat well below room temperature, readers should see the diagnostic steps beginning in the article at

DIAGNOSE & FIX AIR CONDITIONER / HEAT PUMP (Found in INDEX to RELATED ARTICLES at our Continue reading suggestions at the end of this article)

On 2011-07-28 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.

On 2011-07-28 by (mod) - lack of refrigerant alone wouldn't keep the equipment from turning on,

Sean:

lack of refrigerant alone wouldn't keep the equipment from turning on, but the system would not produce cool air.

Charllie:

when a blower fan has trouble getting going I suspect a bad start/run capacitor, or a little less often, a bad control switch or relay.

Look under COMPRESSOR & CONDENSING COIL, A/C (Found in INDEX to RELATED ARTICLES at our Continue reading suggestions at the end of this article) for the sub article titled CAPACITORS for HARD STARTING MOTORS

On 2011-07-28 by awisewon

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?


...

Continue reading at CONTROLS & SWITCHES, A/C - HEAT PUMP or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

ELECTRICAL POWER SWITCH FOR HEAT

CAPILLARY TUBES

The main operating controls for HVAC systems and their functions are are discussed at OPERATING CONTROLS, A/C & HEAT PUMP where you will find a discussion of thermostats, zone dampers, and circuit breakers on air conditioners and heat pump systems.

Other air conditioning and heat pump diagnostic procedures are at LOST COOLING CAPACITY.

Or see these

Recommended Articles

Suggested citation for this web page

A/C HEAT PUMP CONTROL / SWITCH FAQs-3 at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to AIR CONDITIONING & HEAT PUMPS

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