Tempstar Thermostat Power Loss

Tempstar air conditioner thermostat display is blank and system does not run

Advertisements

Safety Warning

This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.

If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.

Advertisements

Possible Causes

Blown low-voltage fuse on control board, Broken 24V transformer, Shorted thermostat cable, Loose R or C wire at thermostat or control board

How to Fix / Troubleshooting

Safety first: Turn OFF power to the furnace/air handler before accessing the control board.

Steps:

  • 1. Check thermostat batteries: Replace if your thermostat uses batteries.
  • 2. Inspect low-voltage fuse: On the Tempstar control board, check the small blade fuse and replace with the same rating if blown.
  • 3. Check R and C connections: Ensure the red (R) and common (C) wires are firmly attached at both the thermostat and control board.
  • 4. If fuse blows again: There is likely a short in the thermostat cable or low-voltage wiring; call a technician.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Low-Voltage Fuse
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements