The 5102 fault code appears when:
- The pipe temperature sensor (TH22) in the indoor unit fails
- The pipe temp sensor (TH2) in the OA processing unit fails
Here is how it could be fixed:
When there is a short- or open circuit with the thermostat ON, the outdoor unit won’t restart for 3 minutes. If after 3 minutes the error is restored, the unit will run properly. If not, there will be an error stop.
There is a temp range, within which a short and an open are detectable:
- Short: at 194°F [90°C] or higher
- Open: at -40°C [-40°F] or lower
There is no way the system can detect a sensor error at gas-side under these conditions.