Step 1: Is the fan running?
- Yes → Continue to Step 2
-
No (no airflow at all)
Go to: Fan Not Running or No Airflow
Step 2: Did the unit just start?
-
Yes
→ This is normal. The unit may delay the fan to prevent blowing cold air. - No → Continue to Step 3
Step 3: Is the outdoor temperature very low?
-
Yes
→ Heat pump performance may be reduced in cold weather
→ The unit should switch to electric backup heat
→ Continue to Step 4 - No → Continue to Step 4
Step 4: Is the air warm or cold?
-
Warm air
→ Heating is working, but performance may be limited -
Cold or cool air only
→ Backup heat may not be activating
→ Continue to Step 5
Step 5: Could the unit be in defrost mode?
-
Warm air
→ Heating is working, but performance may be limited -
Cold or cool air only
→ Backup heat may not be activating
→ Continue to Step 6
Step 6: Is a wall thermostat connected?
-
Yes
→ The thermostat may not be sending the correct signal
Go to: Switching from Wall Thermostat to Display Control - No → Continue to Step 7
Step 7: Check Dip Switch Configuration
Incorrect dip switch settings can disable or affect heating.
View: Dip Switch Guide
Ensure heating-related switches are correctly configured
Issue still not resolved?
Please contact support for further assistance - SUBMIT A REQUEST HERE