How to Fix / Troubleshooting

Safety first: Turn off power before removing the thermostat from the wall.

Steps to address buzzing:

1. Identify noise source:
- Listen closely to determine if the sound comes from the thermostat itself or from connected actuators/relays.
2. Check load size:
- Ensure the connected load does not exceed the thermostat's rating, which can stress the relay.
3. Inspect mounting:
- Make sure the thermostat is firmly mounted and not vibrating against the wall or box.
4. Replace thermostat if internal noise persists:
- Continuous buzzing from the relay or power supply indicates internal wear; replace the thermostat.

When to call a professional: If buzzing is accompanied by heat or burning smell, disconnect power and call an electrician immediately.

Thermostat emits a buzzing or humming noise

Possible Causes