- ◦ Unusual noises coming from the heater (banging, whistling, or grinding sounds).
- ◦ There needs to be more adequate heat production or uneven heating across rooms.
- ◦ A sudden increase in energy bills indicates inefficiency.
- ◦ The system frequently turns on and off more than usual (short cycling).
- ◦ Thermostat malfunctions or inconsistencies.