From the hallway, a furnace that will not heat looks the same no matter what broke. Inside the cabinet, though, everything happens in a strict order: inducer on, pressure switch closed, igniter glowing, gas valve open, burners lit, flame proven, and finally the blower moving heat through the ducts. Most of the diagnosis comes down to finding the broken link. In Rockville homes, it tends to be the same handful of culprits: a flame sensor coated in oxide, a hot surface igniter cracked by thermal cycling, a pressure switch held open by a tired inducer or a plugged condensate trap, or a control board with a burned relay.
Cooling trouble instead? See AC Repair.
Signs You Need Furnace Repair in Rockville
Catching these issues early helps you avoid costly problems. These are the signals our technicians see most often:
- Squeals, scrapes, or grinding noises behind the blower door
- A fan that keeps running while the registers blow cool air
- Yellow, wavering burner flames where they should be sharp blue
- Short cycling every few minutes without reaching the setpoint
- Rust streaks, soot, or water around the cabinet or flue
- Flames that start, last a few seconds, and go out again and again
- Clicking and a glowing igniter with no burner flame
- A bang or boom when the burners ignite late
Don't Wait for a Total Failure
Most HVAC failures start small, a weak capacitor, a squealing blower, a system that runs a little longer each week. At the first hint of a problem, call (240) 896-8292 for a fast inspection.
