AC Konking Out ?

[SARGE67]

Perfect timing right here when cooler weather may be upon us. Today when the AC compressor came on, within 15 seconds it shut off and the entire system in closet shut off also as well as the digital Trane thermostat. Like something pulled the plug on it all. But the thermostat immediately starts rebooting itself. When it gets done it starts compressor and everything again shuts down. I used the thermostat to turn off the system and just let the fan run 20 minutes every hour to circulate and works. The compressor has is own breakers on outside wall by it and seems if there was an issue there, it would trip those breakers. No breakers have been tripped anywhere. Now to find an honest HVAC guy who has surely seen this issue before ??

 

[ZX9RCAM]

Do you have an overflow shut off on the drip pan?

 

[SARGE67]

Do you have an overflow shut off on the drip pan?

There are a few PVC gizmos by the unit up high and attached to the PVC pipe going outdoors. It doesn't run long enough now to see if any water is dripping outside but it was the other day. Your question makes great sense though and thanks.

 

[thequintessentialman]

If not the overflow safety, I'd start by checking coil on contactor. Sounds like something is pulling control voltage down below nominal for the electronic tstat. That causes it to shutdown and reboot, but before the [over] load can trip the transformer circuit breaker. Had a similar issue on my heatpump couple of years ago. If it's a heatpump, I'd check 4way valve solenoid too. These can type issues be tricky to track down...

Sent from my SM-G975U using Tapatalk

 

[ZX9RCAM]

There are a few PVC gizmos by the unit up high and attached to the PVC pipe going outdoors. It doesn't run long enough now to see if any water is dripping outside but it was the other day. Your question makes great sense though and thanks.

What I'm talking about would be on the drip pan underneath the unit.

I'm just assuming that you have one.

 

[SARGE67]

This is what I have coming out of the evaporator in closet, no pan observed but sure there is one hidden. I will first pour water down the tall drain pipe to rule out that being clogged up. If water shows outside coming out then gotta figure out how to determine what's going on at the "Safe T Switch" shown. It sends a signal down the wire to the start and stop surely. Many thanks, I hope my issue has been isolated!

 

[Tnhawk]

This is what I have coming out of the evaporator in closet, no pan observed but sure there is one hidden. I will first pour water down the tall drain pipe to rule out that being clogged up. If water shows outside coming out then gotta figure out how to determine what's going on at the "Safe T Switch" shown. It sends a signal down the wire to the start and stop surely. Many thanks, I hope my issue has been isolated!

A few years ago I had an issue with the drain pipe getting blocked causing the switch to trip out the unit. I flush out the pipe every year to prevent it happening again.

 

[Bozz10mm]

This is what I have coming out of the evaporator in closet, no pan observed but sure there is one hidden. I will first pour water down the tall drain pipe to rule out that being clogged up. If water shows outside coming out then gotta figure out how to determine what's going on at the "Safe T Switch" shown. It sends a signal down the wire to the start and stop surely. Many thanks, I hope my issue has been isolated!

Instead of water, pour some vinegar or bleach down the drain pipe. That will (probably) clear it out if it is clogged. Btw, you are lucky. Mine usually conks out on a Friday at 5 pm on the hottest day of the year.

 

[gasgas]

Probably contactor in outside unit

Take low voltage wires apart outside unit
See if thermostat and inside unit runs

 

[Dawico]

There are tons of videos out there to test basic parts of the system. Be sure to pay attention to the safety warnings.

Shop vac the condensate line from the outside and checking the capacitor and connections on the outside unit is where I'd start.

There are a lot of cheapish smaller parts that can cause issues depending on your level of competence to test them.

 

[SARGE67]

This morning at 10am I started the unit and it ran great for hours bringing indoor temp down to 78 from overnight high of 88. Drain line working like a champ, no clog. After reaching 78 it cycled off and on like regular until 2:30 then it all started again, shut off, thermostat rebooting, etc, so turned the system off. That was the hottest part of day with sun beating directly down on outside unit. Around 6 pm I turned it back on after sun passed over and been cooling ever since. Same timeline two days in a row and if tomorrow is the same, my theory will be semi-proven that something within that unit, prolly electrical wiring or contacts is losing contact then ok when cools off. I just want my own info when the tech arrives.

 

[TexasRedneck]

Could be a capacitor - they love to crap out when you least expect it.

 

[no2gates]

Could be a capacitor - they love to crap out when you least expect it.

I've had my AC go out twice and both times it was the capacitor.

 

[SARGE67]

I've had my AC go out twice and both times it was the capacitor.

In the outside unit ?

 

[TexasRedneck]

In the outside unit ?

That's where it's located.....

 

[no2gates]

In the outside unit ?

Yup.

 

[Tnhawk]

In the outside unit ?

yes, the replacement part was only a few dollars on Amazon.

 

[gasgas]

Check the float switch again

Still could be contactor coil shorting

 

[pronstar]

I would look at anything in the chain that would be affected by the sun load…capacitor and fan motor would top my list.

Check the motor resistance when hot and again when cold.

 

[SARGE67]

yes, the replacement part was only a few dollars on Amazon.

Me tapping my palm against my head here. Are you saying AC parts can be bought on Amazon ???