Air Conditioning - AC Cooling Stops Intermittently

I'm having a problem with the cooling unit stopping at random times. This is a split system, with furnace and blower inside and the AC unit outside. When the system is running, everything will be working, but then I'll notice the temp and humidity rise. The inside blower will be running, but the outside AC is not running(no sounds at all). If I turn everything off and back on in about 15 minutes it will usually start running again, but not always.

I first thought this to be a tstat problem, but last night this happened and I bridged the R (power) directly to the Y (cooling unit) and the unit did not start up. I had my wife bridge these while I was near the outdoor unit, and I heard no clicks or humming. I let it sit for about 10 minutes and then bridged and it worked. It ran correctly for the rest of the night. This seems to be happening more during the evening hours, but it has happened during the day too.

Is there a switch, fuse or relay that could get tripped, and then reset itself after a while?

Any help is appreciated.

Does the contactor pull in when you switch to cooling?

Info helps Dont know for sure just what you have there for heat and AC.
But is there a board in the outdoor unit? . Should be a wire schematic in side it Id check that out. When its goes off is there 24V to the contactor??? will it run then if you just push the contactor down?? KNOW WHAT YOU ARE DOING IF YOU TRY THIS it 220V.
When it does run is the small copper line warm to hot and the big copper line cold and wet/At the outdoor unit??
Stay in the same post.

ED;)

Info helps Dont know for sure just what you have there for heat and AC.
But is there a board in the outdoor unit? . Should be a wire schematic in side it Id check that out. When its goes off is there 24V to the contactor??? will it run then if you just push the contactor down?? KNOW WHAT YOU ARE DOING IF YOU TRY THIS it 220V.
When it does run is the small copper line warm to hot and the big copper line cold and wet/At the outdoor unit??
Stay in the same post.

ED;)

I have a similar problem as well. Ac starts runs until room reaches temp shuts down but then does not come back on. Contactor justs clicks. when it clicks it is not getting 24v.
been stumped for two weeeks. changed contactor, defrost relay, capacitor, hard start cap, all wire spades and unions, still have problem.

i wish i could help. i am having very similar prob. i posted below some of the things i tried replacing only to still have prob.
i am not getting 24v at contactor when it is not working but i don't know why not 24v. like you if i let it sit for a while it does start but after it cycles it won't come back on.
when ti is on the temp goes down. air out of vent is 56-60 degrees F. not sure if pressure has anything to do with it. i have a dealy timer also. it seems to keep clicking so i figure it is working. my unit is also a two stage heat pump. i'm pretty sure it was working properly during the heat season. too hot to switch back.
this electrical stuff came be boggling sometimes. reply with any ideas. maybe we can combine and solve it together.
good luck.




I'm having a problem with the cooling unit stopping at random times. This is a split system, with furnace and blower inside and the AC unit outside. When the system is running, everything will be working, but then I'll notice the temp and humidity rise. The inside blower will be running, but the outside AC is not running(no sounds at all). If I turn everything off and back on in about 15 minutes it will usually start running again, but not always.

I first thought this to be a tstat problem, but last night this happened and I bridged the R (power) directly to the Y (cooling unit) and the unit did not start up. I had my wife bridge these while I was near the outdoor unit, and I heard no clicks or humming. I let it sit for about 10 minutes and then bridged and it worked. It ran correctly for the rest of the night. This seems to be happening more during the evening hours, but it has happened during the day too.

Is there a switch, fuse or relay that could get tripped, and then reset itself after a while?

Any help is appreciated.

OK. If you are not getting 24 volts at the relay, then your problem is in the low voltage contols or wiring. Replacing parts on the high voltage side at the condensing unit (such as relay, capacitor, hard start, etc.) will do no good.

You'll need a good meter and you will have to track it down. Your job is far more difficult when the problem is intermittent. You may have to start at the transformer or the relay and test everything in between. There is no other way. The possibilities include bad circuit board in the air handler, bad connections anywhere, bad time delay relay, bad stat.

Good luck and let us know what you find.

I take it that when it runs . The big copper line is cold and wet the small copper line warm to hot . At the outdoor unit?????

ED;)

I take it that when it runs . The big copper line is cold and wet the small copper line warm to hot . At the outdoor unit?????

ED;)
yes when it runs all is working. if i push in contactor it will run while i hold it but not by itself. now my tstat says in recovery and i don't even get a clicking at contactor. i have an anti-cycle timer on it. waiting for a replacement/cross reference. the one in there is a watsco HQ 1060410WA
EAC 511/4-030A delay on break timer 1Amp max 24vac. any thoughts?

toncab --Guys --- it helps if you have your own post here. We can follow it a lot better than 2 post in one

toncab If you jump R to G does the inside blowe come on??? If you tie R Y and G will teh unit keep running????

ED;)

yes when it runs all is working. if i push in contactor it will run while i hold it but not by itself. now my tstat says in recovery and i don't even get a clicking at contactor. i have an anti-cycle timer on it. waiting for a replacement/cross reference. the one in there is a watsco HQ 1060410WA
EAC 511/4-030A delay on break timer 1Amp max 24vac. any thoughts?
Jump the time-delay. No ned to wait on a new one.