I have two units one for upstairs and one for down. On the upstairs unit the fan and compressor will not run. Tried to turn off breaker to see if maybe woud reset any electronics. Pushed reset button on thermostat. Tried swapping out thermostat with one from the other unit.(they just plug in). Did not see anything abnormal at evaporator. Found black rocker switch I assume maybe a rest button, pressure cut out or something similar, tried that and heard a click. Still nothing. All functions on the digital thermostat seem to be working just nothing tuns on. Was working fine and then not working. Only about four years old and serviced two years before.
An expert who has achieved level 3 by getting 1000 points
An expert that got 10 achievements.
An expert that got 5 achievements.
An expert who has written 7 tips or uploaded 3 video tips
Re: fan and compressor will not run
Ok here is what Im wondering. Most of the gas furnaces sold here in USA have what we call a "door switch" If the panel thatcoveres the blower door is left off nothing will run. If the door switch is bad , nothing will run. Then on some gas furnaces there is a fuse on the control board, if its blown it may cut off the 24vac power and this could be the trouble. If the fuse is blown dont use anything bigger than 5 amp. If it blowes again check for tstat wires together or grounded. If none showing get back to me and I'll help you decide lnext step. 1 of these items Ive mentioned may allrteady be the trouble. Please rate me as high aS you can and thank you for using fix ya.
a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need. goodluck!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
possible bad capacitor for compressor. or burnt wire connection at several locations inside the unit. a look see at the capacitor can tell if the cap is swelled up-it's bad. it is possible for a voltage spike ,during a storm, to cause these problems.if you remove the electrical panel door,of the unit, be sure to turn off high voltage to the unit at the breaker. remember that a capacitor stores a charge that will electrocute you even if high voltage is turned off at the breaker!!!!!!!!
you have a 'direct short' - most likely the compressor or fan motor.
you could isolate it to one or the other by (be sure all power is off) disconnecting one of them and turning the unit back on.
For example if the fan motor is shorted and you disconnect it - the breaker will hold and not trip and the compressor will come on - which will tell you that you need to replace the fan motor.
If you do this and it still trips the breaker then reconnect the fan motor and disconnect the compressor and try that.
If the breaker holds and the fan motor runs then you know the compressor is shorted.
Note: the fan motor can be replaced with not a lot of trouble depending on how mechanically inclined you are - but the compressor will take a qualified serviceperson.
The breaker tripping when you turn the unit on indicates a 'direct short' and 99 out of a 100 times the short will be either the outside fan motor or the compressor itself. Either way - you will need a qualified serviceperson to diagnose this problem correctly and make the needed repairs.
Best solution is to call AC person.
However, here's a good way you can get it down to either the fan motor or the compressor.
(1) With all power OFF - disconnect the wires to the fan motor
(2) turn on AC unit
(a) if breaker trips it means the compressor is probably the shorted component.
(b) if breaker DOES NOT trip and the compressor runs - it means the fan motor is shorted.
(3) If breaker tripped with the fan motor disconnected meaning the compressor is probably shorted you can then (with ALL POWER OFF) 'disconnect the wires going to the compressor' and re-connect the fan motor wires. Turn on power - and if fan motor runs (with compressor wires off) you know it's the compressor that is shorted.
After all this you will now know which of the two (compressor or fan motor) is shorted.
If it's the fan motor you can with 'limited mechanical experience' change the motor yourself, but if it's the compressor you will need to call a serviceperson because of the expertise needed to replace the compressor.
Turn the thermostat as low as it will go and have someone stand out side, they should here the condensor fan and compressor come on at the same time. They are two distinctive sounds so you should
be able to tell if the compressor is running.
If nothing happens and you are skilled with electrical
you can turn power off and remove the electrical
cover to the outside unit. Restore power and carefully
push in the contactor, if the fan and compressor
starts you have a thermostat or low voltage problem.
If just the outdoor fan runs on any attempt, more than likely you need a new capacitor.
The first thing to check is your breaker box. There should be one double breaker for the air handler unit, that's the inside unit, and one double breaker for the compressor, that's the outside unit. Check both breakers. If you're not sure if they've be thrown, click them toward the outside of the breaker box (off position) and then click them toward the inside of the breaker box (on position). If the breakers are on and you still are not getting any A/C take a look at your compressor, (outside unit). If the fan is running at least you're getting power. However, your compressor down inside the unit may not be getting power or it may need to be replaced. The compressor has a start-up cap. If this cap goes bad or the wires from this cap fry or corrode away, this will also keep the compressor from starting but the fan will still run. If the fan is not running it could be caused by a faulty relay inside the compressor cabinet. This relay is supposed to open and close based on a low voltage signal from the thermostat. I believe it's roughly 24 volts. This relay switches on and off the 240 volts for the compressor and the compressor fan. Often this relay goes bad or the wires leading up to it fry. If you?re going to work on the unit yourself make sure all power is shut off. There should be a shutoff switch on the outside wall near the compressor. I?d also shut the breakers off.
Sounds like your Capacitor is bad, or you had a wire burn off compressor terminal or capacitor. Way you can check capacitor is take cover off and see if looks swollen. Make sure to turn off power before taking panel off.