Lux Electrical Noise or Relay Vibration

Thermostat emits a buzzing or humming noise, especially when calling for heat or cool

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

Loose internal relay, Marginal 24VAC transformer causing chatter, Resonance of thermostat housing on wall

How to Fix / Troubleshooting

Safety: Turn off HVAC power before handling the thermostat.

  • Confirm source: Place your ear near the thermostat to verify the noise is from the thermostat and not from ducts or the furnace.
  • Secure mounting: Ensure the Lux wall plate is firmly attached and that the thermostat snaps on tightly without gaps.
  • Check transformer: Have an HVAC technician test the 24VAC transformer for proper voltage and replace if it is noisy or unstable.
  • Replace thermostat: If the internal relay is chattering or buzzing despite proper voltage, replace the thermostat.
Advertisements

Repair Difficulty

Medium 3/5

Required Part

Lux Smart Thermostat Main PCB (relay section)
Check Price on Amazon

We may earn a commission from links on this page.

Advertisements