Heat Pump Repair in Perrysburg, OH 43551
“Zack (and Justin): How difficult is it to replace a cold sensor? The heat pump [at 4779 Genoa Rd] seems to run okay in cool mode. Further investigation has lead me to believe the heat sensor 4S1, either a thermocouple or thermistor, has drifted and now causes the microprocessor 1U1 to believe the water exit temperature is below the freeze point [intended to be 35 degree F], at a higher actual temperature – thus causing the unit to go into manual lockout mode and initiate the Alarm signal at terminal 1TB2-9 which in this system causes an external control relay to shut off the run signal shortening the cycle. This is per design, and a fix would be to replace the sensor or do nothing at this time. Thanks for responding reasonably for the service call.”