Thermostat blank

The thermostat display is dark or unresponsive.

Controls

normal

Diagnosed here

Low Voltage Fuse Keeps Blowing
Troubleshooting
Finding the short in a 24 volt control circuit rather than replacing fuses and transformers.

Possible cause

Control Transformer
Component
The component that creates the 24 volt control circuit, how it is sized, and why its fuse keeps blowing.
Thermostats and Control Wiring
Component
What each control wire does, how thermostat types differ, and how to troubleshoot a control circuit.

Local Code Notice

HVAC installation, venting, combustion air, ventilation air, gas piping, clearances, termination locations, electrical requirements, permits, and equipment requirements vary by jurisdiction and equipment. Always verify the applicable local codes, adopted code edition, regulations, permits, and manufacturer installation instructions before installation or service.