!
error Honeywell
Error Code Blank display
The thermostat screen is not showing any information.
? What Causes This
Power issue, circuit breaker tripped, power switch off, furnace door open, or dead batteries.
✓ How to Fix It
- Check if circuit breaker needs to be reset.
- Verify power switch is turned on.
- Ensure furnace door is closed securely.
- Install fresh batteries correctly.
Source: page 2 of the official manual
From the manual
This error code appears in:
Honeywell T1 Pro Thermostat