Furnace Cleaning

The burner assembly comes out or gets accessed in place, and each burner port is cleaned so the flame pattern is even and fully lit rather than lazy and partial. Uneven burner flame is a direct cause of soot, delayed ignition, and localized heat-exchanger stress.

The flame sensor gets cleaned with the correct abrasive and then verified in microamps — not just wiped and hoped. A sensor reading below spec is the most common reason a furnace lights, runs for thirty seconds, and shuts off in a repeating loop.

The igniter is inspected and resistance-tested, the inducer wheel and housing are cleaned, the pressure-switch port and tubing are checked and cleared, the heat exchanger surfaces are inspected and vacuumed, the blower compartment and wheel are cleaned, electrical connections are tightened, and the filter is replaced with the correct size. On condensing furnaces the condensate trap and drain get flushed.

Cleaning a gas furnace without checking combustion is half a job. Once the unit is clean we verify draft, inspect the vent connections, check for gas leaks at the fittings, confirm manifold gas pressure against the nameplate, test the rollout and limit switches, and measure carbon monoxide at the supply registers.

The heat exchanger inspection matters most. Combustion soot patterns, flame disturbance when the blower starts, and analyzer readings are all evidence, and a visual inspection of the accessible exchanger surfaces is part of every cleaning. If we find a crack we shut the unit down, photograph it, and walk you through the options — we do not patch heat exchangers.

We finish by measuring temperature rise across the exchanger and comparing it to the nameplate range. That number tells you whether the airflow the furnace is getting matches what it was designed for, and it is the difference between a clean furnace and a clean furnace that will actually last.

It lights and then shuts off within a minute or two, repeatedly. It takes several attempts to light. There is a persistent burning-dust smell that does not clear after the first ten minutes of the season. You hear a small boom or whoomph at ignition rather than a smooth light — that is delayed ignition and it is worth treating as urgent.

Visual signs: soot or discoloration around the burner compartment, yellow or lazy flame rather than crisp blue on a gas furnace, rust flakes in the cabinet, or visible nesting material and droppings in an attic or closet unit.

Circumstantial signs: the unit has not been serviced in more than two years, you just bought the home and have no history, there has been remodeling or a re-roof, or the filter was left in place for an entire cooling season. Any one of those is enough.

Annually, in the fall, before the heating season. That is true even in a climate where the furnace runs a couple hundred hours a year, because the failure mechanism here is dust and idleness rather than runtime.

If you are on a maintenance plan, this work is included in the fall heating visit along with the full measurement set and written report — most homeowners with both heating and cooling equipment find the plan is better value than two standalone visits.

Furnace cleaning is not duct cleaning, and the two solve different complaints. If the problem is dust reappearing on furniture and at the registers, the duct system is the target. If the problem is the furnace not lighting or not running cleanly, this is the service.