Most furnace breakdowns give warning signs first. Calling at the first sign usually means a smaller, less expensive repair.
- Cold or lukewarm air coming from the vents, even with the thermostat turned up
- The furnace will not turn on, or the blower runs but no heat follows
- Short cycling, where the furnace starts and stops every few minutes
- New noises such as banging, squealing, grinding, or rattling
- Uneven heat, with some rooms warm and others cold
- More than 15 to 20 year old furnace
- A yellow or flickering burner flame instead of a steady blue one
- Rising energy bills without any change in how you use your heat
- A burning smell that lasts beyond the first few days of the heating season
