Problems with Evolution A/C (probably stat?)

[jeffw_00]

so what should i DO about the sensor - find and reposition it? Get it replaced?

Thanks
/j

[pgmr]

Our Bryant Evolution had an erratic temp display. Turned out to be the temp sensor was left inside the unit, so any heat it generated was picked up by the sensor. I moved it outside the unit. It still gets affected by the morning sun a couple months of the year, but only for a few hours.

[plain spoken]

If this is the new style equipment like he said it was, the sensor is factory mounted and should not be relocated. If it is the older style you may exactly right. Either way it sounds like some outside source, electrical interference or convection, is effecting the sensor and not a problem with the sensor itself.

[jeffw_00]

I think it's heat from the unit itself. I put my regular sensor on top of the compressor and left it there for a few hours. I'm starting to think

a) the sensor is ok
b) the sensor's reading is influenced by heat from the compressor.

Does it really matter? What does the system use the temp for? (other than low-temp cutoff)

/j

[plain spoken]

On your straight cooling unit it is used for low cooling lockout, crankcase heater lockout and low ambient fan control. None of these will be adversely effected by the way you describe it only being a few degrees out as all of these are only "cool" weather controls.

[jeffw_00]

thanks - though even in cool weather (high 50s) I've seen it read 5-10Deg high
/j

[plain spoken]

The few degrees out of calibration will not be a problem for unit operation, forget it.