You’ve got a York thermostat, and it doesn’t work for some reason? Use the York thermostat troubleshooting manual from this page: it describes the most common technical problems, their possible reasons, and the ways to fix the issues. The tables cover different York models, and also include error codes.
| Problem | Cause | Solution |
|---|---|---|
| The air conditioning does not attempt to turn on. | The compressor timer lockout may prevent the air conditioner from turning on for a period of time | Consult the Owner’s Manual in the Installer Setup section to defeat the Cycles Per Hour |
| The display is blank | Lack of proper power | Make sure the power is on to the furnace and that you have 24vac between R & C |
| The air conditioning does not attempt to turn on. | The cooling setpoint is set too high | Lower the cooling setpoint or lower the cooling set- point limit. |
| The heating does not attempt to turn on | The heating setpoint is set too low. | Raise the heating setpoint or raise the heating set- point limit |
| When controlling a residential heat pump, and asking for cooling, the heat comes on. | The thermostat reversing valve jumper is set for “B”. | Set the reversing valve jumper for “0”. |
| When calling for cooling, both the heat and cool come on | The thermostat equipment jumper is configured for “HP” and the HVAC unit is a Gas/Electric. | Set the equipment jumper for “Gas” |
| When the Program button is pressed, the display reads “DISABLED”. | Program mode is set to “NON PROGRAM”. | Set Program Mode to 1. 5/2, or 7 Day |
| Problem | Solution |
|---|---|
| Thermostat has no dlsplay | Check wiring between thermostat and sensor. Incorrect wiring can damage the thermostat, transformer or blow a fuse. Check 24VAC supply |
| Thermostat reads “AC” | 24VAC power is disconnected |
| Not sure if dlsplay Is showing local or remob temperature | Breathe on the wall near the bottom left corner of the thermostat. Temperature will go up for a few seconds if sensing locally |
| Thermostat displays very high temperature | Wires on sensor element are shorted together. Separate them |
| Thermostat displays very low temperature | Check wiring of probe or duct sensor. Sensor element is not connected to board or is broken |
| Temperature display jumps up and down several degrees within seconds | Thermostat requires a few seconds to stabilize after power is turned on. If display continues to be erratic, there is too great a distance between the indoor sensor box and the duct sensor. Move the box closer to the duct sensor or use shielded cable |
| Code | Designation |
|---|---|
| 11/21/31 | Compressor discharge temperature surpased or short circuited probe |
| 12/ 22 /32 | High Pressure switch, outdoor fan overload or compressor motor protection module |
| 13/23/33 | Low Pressure switch |
| 14 | Indoor fan thermal switch |
| 15/25/35 | Repeated start-ups in cool, or suction temperature < -25°C |
| 16 | Liquid temperature < -30°C |
| 41 | Gas 1 or electrical heater 1 |
| 42 | Gas 2 or electrical heater 2 |
| 43 | Electrical heater 3 |
| 44 | Electrical heater 4 |
| 45 | Economizer or hot water coil |
| 46 | Smoke detector, fire thermostat or air discharge temperature probe (rooftop only) >80°C |
| 91 | Selected probe not valid or short circuited probe |
| 92 | Thermostat internal probe not calibrate |
| 93 | No communication between the thermostat and the main PCB (Yklon) |
| 94 | Failure with terminal “AL” connected |
| 95 | Digital probe S5 not detected |
| 96 | Digital probe S6 not detected |
| 97 | Digital probe S7 not detected |
| 98 | Digital probe S8 not detected |
| 99 | Outdoor digital probe not detected |