GeoSmart Premium G Airflow Fault

Premium G Water to Air Geothermal Heat Pump Air Flow Fault

Air Flow fault: The fan RPM falls below the low RPM limit for 30 continuous seconds

1. Fan may not be spinning freely (Bearings in the fan motor may be damaged)
2. Line voltage at terminals 4 & 5 may be below 230V
3. The signals from the board may need to be checked.
4. Dirty air filter or coil

Checking ECM Motors

1. Remove the plug on P1 to disconnect the main logic board from the thermostat.
2. On the P1 connection, place a jumper between terminals R and G (SW2 DIP switch # 8 in the off position) • The fan should come on and run on low speed.
3. Check Outputs 2 on the main logic board (SW2 DIP switch # 6 and # 7 off) to confirm blower low speed output. • Drain LED should be lit.
4. Place SW3 DIP switch # 3 in the off position; this disables RPM monitoring.
5. Disconnect low voltage harness from motor and check DC voltage between violet and black wires. If 24 VDC is present, check the motor.
6. To check the motor, remove module from motor and disconnect 3 pin connector. Place an ohm meter across each pin and motor housing (ground), reading should be over 100,000 ohms.
7. Take ohm reading at the three pin connector (motor windings). Resistance across any two leads should be less than 20 ohms and within 10 percent of each other.
8. If the motor checks out within the above tolerances and the bearings feel good, replace the module only.