Honeywell TrueDRY DH150 Guide D'installation page 15

Troubleshooting
Problem
Impeller fan does not run with fan
switch in either position. Impeller
fan does not run with ventilation
timer activated. Compressor runs
briefly but cycles on & off with
humidity control turned to ON.
Impeller fan runs with fan switch
ON. Impeller fan does not run with
ventilation timer activated.
Evaporator coil frosted continu-
ously, low dehumidifying capacity.
Unit not providing ventilation.
Ventilation timer not operating
correctly.
Unit removes some water, but not
as much as expected.
Recommended Troublshooting Steps
1. Loose connection in impeller fan circuit.
2. Obstruction prevents impeller fan rotation.
3. Defective impeller fan.
4. Defective impeller fan relay.
5. Defective impeller fan capacitor.
1. Defective ventilation timer.
2. Time not correct on ventilation timer.
3. Ventilation timer set to manual & switched OFF.
4. Defective fan switch.
1. Defrost thermostat loose or defective.
2. Low refrigerant charge.
3. Dirty air filter(s) or airflow restricted.
4. Excessively restrictive ducting connected to unit.
1. If timer is not functioning correctly reset timer and reprogram.
2. Check control wire connections (check connections at fresh air damper
also).
3. Defective fresh air damper.
4. Defective fan switch.
1. Air temperature and/or humidity have dropped.
2. Humidity meter and or thermometer used are out of calibration.
3. Unit has entered defrost cycle.
4. Air filter dirty.
5. Defective defrost thermostat.
6. Low refrigerant charge.
7. Air leak such as loose cover or ducting leaks.
8. Defective compressor.
9. Restrictive ducting.
10. Optional Condensate Pump Safety Switch open.
13
TrueDRY DH150
69-2271EFS—01