AC Intermittently not working.
 

I have an outside unit AC. Air handler and condenser unit all in one.
I keep on getting an intermittent failure of the compressor to kick on.
I've noticed it for off and on for several weeks.
The house will be warm. Tstat says cooling is on, but temp is 3-5 degrees warmer and just the fan running.
Sometimes it quits at night and then kicks on at mid-morning.
The fan kicks on, but no compressor or condenser fan operation.
Then it works fine for five days.
Then today it never kicked on from about 10am until around 4. It was in the mid to upper 80s outside. Working and cycling perfectly fine right now.
Where should I go from here?
Thanks

AC Intermittently not working.
 

On Sunday, June 3, 2018 at 6:06:08 PM UTC-4, Scott Frederick wrote:
I have an outside unit AC. Air handler and condenser unit all in one.
I keep on getting an intermittent failure of the compressor to kick on.
I've noticed it for off and on for several weeks.
The house will be warm. Tstat says cooling is on, but temp is 3-5 degrees warmer and just the fan running.
Sometimes it quits at night and then kicks on at mid-morning.
The fan kicks on, but no compressor or condenser fan operation.
Then it works fine for five days.
Then today it never kicked on from about 10am until around 4. It was in the mid to upper 80s outside. Working and cycling perfectly fine right now.
Where should I go from here?
Thanks

Are you sure you mean air handler and condenser all in one? Typically
the air handler and evaporator are in one unit inside and the compressor
and condenser are outside in another unit. Assuming the latter is what
you have, one easy thing to check is if the condenser fan outside is
working when it's acting up. The fan is typically connected to the
contacter, so if it's getting 24V and the contacter is working and the
fan is working it should be running. If the fan is bad it can run
intermittently and when it stops, the compressor will reach an over
pressure cutoff shortly and quit. Next would be to check if there
is power at the unit when it's acting up and if there is 24V AC at the contacter. If you're comfortable working with electricity and have a meter
you can check it. If not, probably time for a service call.

AC Intermittently not working.
 

On Sunday, June 3, 2018 at 8:38:01 PM UTC-4, trader_4 wrote:
On Sunday, June 3, 2018 at 6:06:08 PM UTC-4, Scott Frederick wrote:
I have an outside unit AC. Air handler and condenser unit all in one.
I keep on getting an intermittent failure of the compressor to kick on.
I've noticed it for off and on for several weeks.
The house will be warm. Tstat says cooling is on, but temp is 3-5 degrees warmer and just the fan running.
Sometimes it quits at night and then kicks on at mid-morning.
The fan kicks on, but no compressor or condenser fan operation.
Then it works fine for five days.
Then today it never kicked on from about 10am until around 4. It was in the mid to upper 80s outside. Working and cycling perfectly fine right now.
Where should I go from here?
Thanks

Are you sure you mean air handler and condenser all in one? Typically
the air handler and evaporator are in one unit inside and the compressor
and condenser are outside in another unit. Assuming the latter is what
you have, one easy thing to check is if the condenser fan outside is
working when it's acting up. The fan is typically connected to the
contacter, so if it's getting 24V and the contacter is working and the
fan is working it should be running. If the fan is bad it can run
intermittently and when it stops, the compressor will reach an over
pressure cutoff shortly and quit. Next would be to check if there
is power at the unit when it's acting up and if there is 24V AC at the contacter. If you're comfortable working with electricity and have a meter
you can check it. If not, probably time for a service call.

Also if it's not working, listen for a hum from the contacter, which
is the power relay. If there is a hum, then the 24V is making it from
the air handler to the outside unit.

AC Intermittently not working.
 

On Sunday, June 3, 2018 at 5:06:08 PM UTC-5, Scott Frederick wrote:
I have an outside unit AC. Air handler and condenser unit all in one.
I keep on getting an intermittent failure of the compressor to kick on.
I've noticed it for off and on for several weeks.
The house will be warm. Tstat says cooling is on, but temp is 3-5 degrees warmer and just the fan running.
Sometimes it quits at night and then kicks on at mid-morning.
The fan kicks on, but no compressor or condenser fan operation.
Then it works fine for five days.
Then today it never kicked on from about 10am until around 4. It was in the mid to upper 80s outside. Working and cycling perfectly fine right now..
Where should I go from here?
Thanks

Your AC unit could have a capacitor that's going bad or a bad connection. Quite often a 1/4" Faston connection will go bad somewhere in the wiring. Another problem I've found in outdoor units is ants. The contractor(big relay) has power flowing through its coil all the time because of the heat anticipator circuit in the thermostat. This electrical current actually makes the contactor warm. The warmth attracts ants which often decide its a good place for a nest. I've even pulled cockroaches out of the dang contactors before. I'd open the control box on the outdoor package unit and look for bugs, living, dead or electrical. ^_^

[8~{} Uncle Bug-eyed Monster

AC Intermittently not working.
 

Your AC unit could have a capacitor that's going bad

+1

my AC had this exact symptom and the problem was the running cap was starting to go bad.

new cap and it starts perfectly and draws less current when running.

m

AC Intermittently not working.
 

On 6/3/2018 8:37 PM, trader_4 wrote:
Are you sure you mean air handler and condenser all in one? Typically
the air handler and evaporator are in one unit inside and the compressor
and condenser are outside in another unit. Assuming the latter is what
you have, one easy thing to check is if the condenser fan outside is
working when it's acting up.

Not only are you often wrong politically, maybe you got the OP's HVAC systems wrong too.

Meet the Goodman All-in-One Packaged Unit.Â* ;-)

https://goodmanmfg.com/products/pack...16-seer-gpg16m

AC Intermittently not working.
 

On Monday, June 4, 2018 at 11:53:33 AM UTC-4, I. M. Wright wrote:
On 6/3/2018 8:37 PM, trader_4 wrote:
Are you sure you mean air handler and condenser all in one? Typically
the air handler and evaporator are in one unit inside and the compressor
and condenser are outside in another unit. Assuming the latter is what
you have, one easy thing to check is if the condenser fan outside is
working when it's acting up.

Not only are you often wrong politically, maybe you got the OP's HVAC systems wrong too.

Meet the Goodman All-in-One Packaged Unit.Â* ;-)

https://goodmanmfg.com/products/pack...16-seer-gpg16m

I wasn't wrong. I said it's *typically* not the case to have the
air handler and condenser in one unit. I didn't say it doesn't exist.
What he actually has, who knows because he hasn't been heard from again.

AC Intermittently not working.
 

Thanks for the information. It's been 26 hours of functioning correctly.
It's a Goodman GPH1336H41AC all-in-one heatpump package unit for a cabin.
No condenser fan or compressor operation when acting up. Just the air handler fan.
Seems to be one of three things: thermostat, contacter, or transformer.
So I got my multimeter and I'm waiting for it to fail again.

AC Intermittently not working.
 

On Monday, June 4, 2018 at 6:34:51 PM UTC-4, Scott Frederick wrote:
Thanks for the information. It's been 26 hours of functioning correctly.
It's a Goodman GPH1336H41AC all-in-one heatpump package unit for a cabin.
No condenser fan or compressor operation when acting up. Just the air handler fan.
Seems to be one of three things: thermostat, contacter, or transformer.
So I got my multimeter and I'm waiting for it to fail again.

I think you can probably rule out the thermostat. The thermostat only
calls for cooling, the air handler is turned on by the controller board.
The thermostat can turn the air handler on separately, if you want fan
only, but in cooling mode it's turned on by the system. So, if the air
handler is running, I'd check to see if the contactor has 240V on either
side and if it has it's 24V turn on voltage.

AC Intermittently not working.
 

On Monday, June 4, 2018 at 10:23:58 PM UTC-4, trader_4 wrote:
On Monday, June 4, 2018 at 6:34:51 PM UTC-4, Scott Frederick wrote:
Thanks for the information. It's been 26 hours of functioning correctly.
It's a Goodman GPH1336H41AC all-in-one heatpump package unit for a cabin.
No condenser fan or compressor operation when acting up. Just the air handler fan.
Seems to be one of three things: thermostat, contacter, or transformer.
So I got my multimeter and I'm waiting for it to fail again.

I think you can probably rule out the thermostat. The thermostat only
calls for cooling, the air handler is turned on by the controller board.
The thermostat can turn the air handler on separately, if you want fan
only, but in cooling mode it's turned on by the system. So, if the air
handler is running, I'd check to see if the contactor has 240V on either
side and if it has it's 24V turn on voltage.

yep, unlike what I said before I would rule OUT the compressor run capacitor if you say BOTH the compressor and condenser fans fail to run.

m

AC Intermittently not working.
 

On Tuesday, June 5, 2018 at 10:49:16 AM UTC-4, wrote:
On Monday, June 4, 2018 at 10:23:58 PM UTC-4, trader_4 wrote:
On Monday, June 4, 2018 at 6:34:51 PM UTC-4, Scott Frederick wrote:
Thanks for the information. It's been 26 hours of functioning correctly.
It's a Goodman GPH1336H41AC all-in-one heatpump package unit for a cabin.
No condenser fan or compressor operation when acting up. Just the air handler fan.
Seems to be one of three things: thermostat, contacter, or transformer.
So I got my multimeter and I'm waiting for it to fail again.

I think you can probably rule out the thermostat. The thermostat only
calls for cooling, the air handler is turned on by the controller board.
The thermostat can turn the air handler on separately, if you want fan
only, but in cooling mode it's turned on by the system. So, if the air
handler is running, I'd check to see if the contactor has 240V on either
side and if it has it's 24V turn on voltage.

yep, unlike what I said before I would rule OUT the compressor run capacitor if you say BOTH the compressor and condenser fans fail to run.

m

That's a good point too. If he can watch it as it happens, the sequence
can be probative too. For example, if the fan is intermittent, the fan
could stop, which then causes the coil to get too hot and then the
compressor safety stops the compressor shortly after. They both wind
up off, but how they got there is important.

That was happening on my Rheem system that was only two years old.
It had one of those fancy new ECM condenser fan motors. You know,
the ones that cost 4x what a regular motor costs and save you $3
a season in electricity? I replaced it with a regular motor for $90.
But that's what it was doing, the fan motor would stop, then the
compressor would trip off.

AC Intermittently not working.
 

Thanks for the info.
I'm still waiting for a repeat of the symptoms to do an actual voltage check.

When the compressor/fan wasn't running the thermostat was showing cooling on.
There's no compressor operation and no fan operation. Even after power cycling at the fuse box and thermostat (delay). I can look down on the unit condenser fan through a window within 5 seconds of the thermostat kicking on cooling.

So most likely it's a contactor, since the thermostat has power without the batteries during the event, and is intermittent (cycles fine for hours or days before failure) right?

AC Intermittently not working.
 

On Tuesday, June 5, 2018 at 1:12:29 PM UTC-4, Scott Frederick wrote:
Thanks for the info.
I'm still waiting for a repeat of the symptoms to do an actual voltage check.

When the compressor/fan wasn't running the thermostat was showing cooling on.
There's no compressor operation and no fan operation. Even after power cycling at the fuse box and thermostat (delay). I can look down on the unit condenser fan through a window within 5 seconds of the thermostat kicking on cooling.

But the air handler is running when this problem happens, right?
Just no compressor and condenser fan, right?



So most likely it's a contactor, since the thermostat has power without the batteries during the event, and is intermittent (cycles fine for hours or days before failure) right?

If the air handler is running, that's one possibility. But
it could be other issues too. You start with the simple, easy ones.