Replacing a room temp sensor

[Richpatty]

Hi all,

I have had an odd problem for a few years. Not a show stopper, but puzzling. When running an AC unit (I think it only effects unit #2 of 3), the unit will stop running before hitting its set point. It will then come back on. See pic. I have asked Micro-air about it thinking it was an issue with their thermostat and although they have offered a discount on a new unit (I am way out of warranty), I would hate to buy a new one and still have the problem. I even had the #2 unit replaced in 2024 and the problem continued.

Micro-air said it could be the room wall sensor…although I am not sure why as it seems to report the temperature correctly. Also replacing it does not look like fun as it goes into the wall. I figure the only thing I could do is cut the head of the sensor off and splice in a new one. Has anyone done this? Or does someone have a better thought or idea? A new sensor is about $50.

Thanks
Rich

 

[Neal]

Do you have the original t-stat you can test with to verify it's not the t-stat?

 

[Richpatty]

Yea…. I guess I could do that. Although I am spoiled by the Micro-Air.

 

[Neal]

I think the thermistor is just a wire. Some surround the void in there with foil I believe. I often use an air can (like for computers) to blow out any dust, etc. The other option is use a laser thermometer gun and hit it and see what temp it shows and compare.

I can't remember but is there a calibration on the new t-stat? Is the firmware up to date? I know they added a hysteresis type thing to set how frequent the unit cycles, i.e. 2 degree temp swing.

Thinking out loud...