A/C will not start

[Rokc]

Hi,

I have a 20 yr old a/c unit, which is my first problem, and it's not starting. When I turn the thermostat on, the fan kicks on and the unit outside makes a click noise like it's going to start but doesn't. The unit has had the motor, contactor, and capacitor replaced within the year and was working fine until yesterday. Any ideas what it could be?

Thanks.

[paul52446m]

Hi,

I have a 20 yr old a/c unit, which is my first problem, and it's not starting. When I turn the thermostat on, the fan kicks on and the unit outside makes a click noise like it's going to start but doesn't. The unit has had the motor, contactor, and capacitor replaced within the year and was working fine until yesterday. Any ideas what it could be?

Thanks.

Take the electric cover off the outside unit. Check to see if you have 240 volt power coming to the unit, if not check fuses and breakers. Check the open points on the contactor for burn, dirt, if a bug gets in there it stops contact.
Paul

[Bill Anderson]

Hi Rokc, I just finished fixing my condensing unit which had the same symptoms as yours. The furnace blower motor runs fine, but the outside condensing unit fan does not. More than likely it is the capacitor which is bad. I also replaced the contactor, as that is another part that also goes bad, and would more than likely be the next thing I would have to replace anyway.

Make sure to mark your wires, and make a detailed diagram, and then double check the diagram to make sure it is correct. I found my parts in town (~120,000 population), in stock and $78 for both parts.

Make sure power is off, you can disconnect at breaker, or there should be an outside power cutoff box near the condensing unit. I did both.

It sound like your compressor is fine, as you are hearing the same "click" from the compressor. If you were low on refrigerant, or the compressor was bad you would not hear that "click", same as a car a/c system.

Also, if you can't find your parts near you, I found a place online called HVAC North America, which was well stocked.

Hope this helps you. Regards, Bill

[paul52446m]

Hi Rokc, I just finished fixing my condensing unit which had the same symptoms as yours. The furnace blower motor runs fine, but the outside condensing unit fan does not. More than likely it is the capacitor which is bad. I also replaced the contactor, as that is another part that also goes bad, and would more than likely be the next thing I would have to replace anyway.

Make sure to mark your wires, and make a detailed diagram, and then double check the diagram to make sure it is correct. I found my parts in town (~120,000 population), in stock and $78 for both parts.

Make sure power is off, you can disconnect at breaker, or there should be an outside power cutoff box near the condensing unit. I did both.

It sound like your compressor is fine, as you are hearing the same "click" from the compressor. If you were low on refrigerant, or the compressor was bad you would not hear that "click", same as a car a/c system.

Also, if you can't find your parts near you, I found a place online called HVAC North America, which was well stocked.

Hope this helps you. Regards, Bill

The click that he he hearing is the relay making from the 24 volt coming from the stat and furnace. If the capacitor was bad the compressor would try to start and over amp and snap the breaker off or blow a fuse. Later Paul

[Bill Anderson]

I guess I should read more closely next time. It still sounds like the capacitor is defective again.

Before it quit working, did you feel that it was cooling your house very well? If so, the freon low pressure switch should not be causing the problem. And you are hearing the compressor "click", so I would guess not the compressor.

One word of caution, if you have to get the entire a/c system upgrade (I would guess you wouldn't have to though, especially if your coils on the condensing unit appear in good condition), make sure to get the new type freon R410. The R-22 a/c systems are still being sold, as there are still some sitting in warehouses.

Let us know what the problem is/was. Good Luck, Bill

[Bill Anderson]

Paul, My second post was posted before your second post, I wasn't contradicting your second post. Just wanted to make sure no offense was taken. I thought that "click" the OP was referring to, was probably the compressor cycling on, but then again maybe not.

Regards, Bill

[Rokc]

Take the electric cover off the outside unit. Check to see if you have 240 volt power coming to the unit, if not check fuses and breakers. Check the open points on the contactor for burn, dirt, if a bug gets in there it stops contact.
Paul

Hi Paul,
I checked the power and contactor and both are good. Any other suggestions?

Thanks.

[Rokc]

I guess I should read more closely next time. It still sounds like the capacitor is defective again.

Before it quit working, did you feel that it was cooling your house very well? If so, the freon low pressure switch should not be causing the problem. And you are hearing the compressor "click", so I would guess not the compressor.

One word of caution, if you have to get the entire a/c system upgrade (I would guess you wouldn't have to though, especially if your coils on the condensing unit appear in good condition), make sure to get the new type freon R410. The R-22 a/c systems are still being sold, as there are still some sitting in warehouses.

Let us know what the problem is/was. Good Luck, Bill

Yes it was cooling great before it stopped working. I'll try replacing the capacitor next. Hopefully that will fix it.
Thanks Bill!

[Rokc]

I finally gave in and called someone. Apparently a wire in the fuse box had burnt out and needed to be replaced and there was also a freon leak so it was adjusted and refilled. He maintenance the entire unit and cleaned the air filter. So 180 bucks later, I can relax in a cooled home.

Thank you all for your help!

[Bill Anderson]

Hey Rokc, Thanks for the update. Glad it all worked out. That seems like a very reasonable price for the repair and refrigerant. When the a/c quits working, especially in the heat we are having now, we learn to appreciate it again, FAST.

Regards, Bill

[Rokc]

Hey Rokc, Thanks for the update. Glad it all worked out. That seems like a very reasonable price for the repair and refrigerant. When the a/c quits working, especially in the heat we are having now, we learn to appreciate it again, FAST.

Regards, Bill

Indeed! Thanks again!

[shellytowns]

I feel your pain when it comes to an AC unit that doesn't work...especially in the heat of summer. I'd definitely recommend having someone come out on an annual basis for older AC units to keep them lasting longer and more efficient. I use ACPro here locally and they do a great job.

[HayZee518]

hey guys, you can't just substitute r-410 for r-22. it operates at a higher pressure than r-22. O rings engineered into an r-22 system are not compatible with r-410.

[paul52446m]

hey guys, you can't just substitute r-410 for r-22. it operates at a higher pressure than r-22. O rings engineered into an r-22 system are not compatible with r-410.

There was no mention in any of these post in this thread about substituting R410 for R22. The gas flow device's and the oil's are not compatibly with each other. I use different gauges, and different charging machine of each of the two gases. Paul