Brand: Honeywell
Category: Thermostat
Document Type:
Language: EN
Manual for T4 Pro - Troubleshooting and error codes + PDF Download
Uploaded: April 8, 2025, 3:37 a.m.
Manual Publish Date: 2017-02-01
Warranty Summary
No warranty information found in this manual.
System Operation Settings:
- Press the Mode button to cycle through available system modes.
- System modes include Auto, Heat, Cool, Em Heat (for heat pumps with auxiliary heat), and Off.
- Auto mode selects heating or cooling as needed.
- Heat mode controls only heating.
- Cool mode controls only cooling.
- Em Heat controls auxiliary heat for heat pumps.
- Off mode turns off heating and cooling, but fan can still operate if set to On or Circulate.
Fan Operation Settings:
- Press the Fan button to cycle through available fan modes.
- Fan modes include Auto and On.
- Auto mode runs fan only when heating or cooling is on.
- On mode keeps fan always on.
Troubleshooting and error codes
| System test | System status |
|---|---|
| Heat 0 | Heat Off |
| Heat 1 | Heat On |
| Cool 0 | Cool Off |
| Cool 1 | Cool On |
| Fan 0 | Fan Off |
| Fan 1 | Fan On |
| Em. Heat 0 (TH4210U only) |
Em. Heat Off |
| Em. Heat 1 (TH4210U only) |
Em. Heat On |
| System test | System status |
|---|---|
| Heat 0 | Heat Off |
| Heat 1 | Heat On |
| Cool 0 | Cool Off |
| Cool 1 | Cool On |
| Fan 0 | Fan Off |
| Fan 1 | Fan On |
| Em. Heat 0 (TH4210U only) |
Em. Heat Off |
| Em. Heat 1 (TH4210U only) |
Em. Heat On |