Trane air handler cycling on and off

[lborne]

In South Florida and I have an 11 year old Trane XLI14, air handler model # 4TEE3F49A1000AB. Starting today, the air handler motor kicks on, ramps up to speed, and then after 2 to 15 seconds, shuts completely off - (no ramp down as usual). Within 2 seconds, it repeats.

I removed the thermostat and connected red and green wires. Same result. Next I removed the side panel near the blower motor. AH is in the attic and it was hot, so I did not stay long. But the contactors were working and the blower moved freely by hand. I'm assuming it is some kind of thermal overload or the time delay relay. I let it rest for about 1 hour, and then it ran fine. But I suspect it is going to do it again soon. Any help would be appreciated.

[Tony Hwang]

Post by lborne
In South Florida and I have an 11 year old Trane XLI14, air handler model # 4TEE3F49A1000AB. Starting today, the air handler motor kicks on, ramps up to speed, and then after 2 to 15 seconds, shuts completely off - (no ramp down as usual). Within 2 seconds, it repeats.
I removed the thermostat and connected red and green wires. Same result. Next I removed the side panel near the blower motor. AH is in the attic and it was hot, so I did not stay long. But the contactors were working and the blower moved freely by hand. I'm assuming it is some kind of thermal overload or the time delay relay. I let it rest for about 1 hour, and then it ran fine. But I suspect it is going to do it again soon. Any help would be appreciated.

Checked starting/run caps.

[lborne]

Thanks. Will check those tonight when it is cooler. Unit worked OK overnight.

On second thought, it seems to be cycling too quickly to be a thermal issue. I also forgot to mention that the compressor is working fine and Freon is good.

[Stormin Mormon]

Post by lborne
Thanks. Will check those tonight when it is cooler. Unit worked OK overnight.
On second thought, it seems to be cycling too quickly to be a thermal issue. I also forgot to mention that the compressor is working fine and Freon is good.

Sure it's Freon? Might be Isotron, or Genetron, or Forane.

[JennG]

Any idea what the issue was? We are having this same exact issue with the same model and replaced the CFM board and thermostat. Outside unit runs fine, doesn't stop when inside handler fan shuts off and on

[Miki Couch]

You are replying to a 6 yo thread and one of the people in it is dead. Call a service person.
On Saturday, October 10, 2020 at 9:31:26 AM UTC-4, JennG wrote: