A modern furnace runs a strict startup sequence, and knowing where the sequence breaks is most of the diagnosis. The thermostat calls, the inducer motor spins up to prove draft through a pressure switch, the hot surface igniter glows, the gas valve opens, the burners light, the flame sensor confirms fire, and only then does the blower deliver heat to the house. In Medford, OR, the failures cluster at predictable points: a flame sensor coated in oxide that can no longer prove the flame, a hot surface igniter cracked from years of thermal cycling, a pressure switch that will not close because the inducer is weak or the condensate trap on a high-efficiency model has clogged, or a control board with a burned relay. Each one stops the sequence cold, and each one mimics the others from the hallway.
When the AC quits in summer, see AC Repair.
When to Call for Furnace Repair in Medford
The sooner you notice these red flags, the easier and cheaper the fix. Keep an eye out for the following clues:
- Grinding or high-pitched squeals from the blower
- Short cycling every few minutes without reaching the setpoint
- A fan that keeps running while the registers blow cool air
- Clicking and a glowing igniter with no burner flame
- Water, rust stains, or black soot around the flue or cabinet
- Repeated shutdowns just seconds after the burners light
- A flame that burns soft and yellow rather than steady blue
- Booming or banging at light-off from delayed ignition
Early Action Saves Money
Left unchecked, even a small fault or temperature swing often signals a system working its way toward a breakdown. Don't wait, call (541) 634-9859 and we'll take a look right away.
