Common Causes
- Dead or low batteries
- A tripped breaker or blown fuse powering the system
- A loose or miswired thermostat connection
- A programming or scheduling conflict
- An incompatible or failing thermostat
- A wiring issue between the thermostat and the equipment
What You Can Safely Check
- Replace the batteries if the thermostat takes them
- Confirm the display is on at all, and check whether the breaker for the HVAC system has tripped (a visual check only)
- Review the programmed schedule for any conflicting settings
When to Call NILOV
- Batteries and a visual breaker check do not resolve it
- The screen stays blank
- You suspect a wiring issue — NILOV handles thermostat wiring rather than homeowners removing the unit from the wall