Furnace Repair in Mountlake Terrace, Snohomish County, Washington

Look for inconsistent room temperatures, strange sounds (rattling, banging, or squealing), frequent cycling on and off, a persistent “burning” odor after the first few minutes of startup, or an unexplained spike in energy bills. Any of these symptoms suggest the system is struggling and should be inspected by a qualified technician.

No. A gas odor—often described as sulfuric or “rotten eggs”—may indicate a leak. Turn the furnace off, open windows, evacuate the area, and call your gas utility or a licensed HVAC professional immediately. Do not relight appliances, flip switches, or use phones inside the home until the leak has been cleared.

Most manufacturers recommend checking the filter every 30 days and replacing it at least every 90 days (monthly in high-use seasons or homes with pets). A clogged filter restricts airflow, forcing the furnace blower to work harder, which can overheat components, reduce energy efficiency, and circulate dust or allergens.

Verify that the thermostat is set to “Heat” and above the current room temperature, check that the furnace switch and circuit breaker are on, and ensure the filter isn’t clogged. If the unit still won’t ignite—or if you see a blinking error code—shut the system off and schedule professional service rather than repeatedly cycling the power.

Schedule an annual professional tune-up (preferably before heating season), keep vents unobstructed, change filters regularly, inspect and vacuum return-air grilles, and install a programmable thermostat to reduce excessive cycling. Consistent maintenance catches minor issues early, extends equipment life, and keeps efficiency high.

Yes. Replacing faulty heat exchangers, sealing duct leaks, cleaning burners, and installing high-efficiency filters all reduce dust, carbon monoxide risk, and airborne contaminants. A well-repaired furnace maintains stable humidity and consistent airflow, both of which contribute to healthier indoor air.