The best way to avoid a heating or cooling emergency is to stay ahead of it. A consistent maintenance schedule keeps your HVAC system running efficiently, extends its lifespan, and helps you catch small problems before they become expensive ones.

Here's a practical maintenance calendar for Snohomish County homeowners.

Monthly Tasks

Check and replace the air filter

This is the single most important thing you can do for your HVAC system. A clogged filter restricts airflow, reduces efficiency, and can cause overheating. Check it monthly — replace it when it looks dirty (typically every 1–3 months depending on your home).

Check thermostat operation

Make sure your thermostat is responding correctly and maintaining the set temperature. If you have a programmable thermostat, verify the schedule is correct.

Listen for unusual noises

A healthy system runs quietly. Banging, rattling, squealing, or grinding sounds are early warning signs worth investigating.

Seasonal Tasks

Fall (Before Heating Season)

This is the most important maintenance window of the year for Snohomish County homeowners.

• Schedule a furnace tune-up — Have a technician clean the burners, check the heat exchanger, test safety controls, and verify proper operation before you need it
• Test your thermostat — Switch to heating mode and verify the system responds correctly
• Check carbon monoxide detectors — Test batteries and replace if needed
• Clear the area around your furnace — Remove any stored items within 3 feet of the unit
• Inspect the flue pipe — Look for rust, gaps, or disconnected sections

Spring (Before Cooling Season)

• Schedule an AC tune-up — Have a technician clean the condenser coils, check refrigerant levels, and test the system before summer
• Clean around the outdoor unit — Remove leaves, grass, and debris from around the condenser
• Check and clean condensate drain lines — Clogged drains cause water damage and system shutdowns
• Test your AC — Run it for 15 minutes on a mild day to confirm it's cooling properly

Summer

• Keep the outdoor unit clear — Trim vegetation to maintain 2 feet of clearance on all sides
• Monitor cooling performance — If the system is struggling to maintain temperature on hot days, schedule a service call before the problem worsens

Winter

• Keep vents and registers clear — Furniture and rugs blocking vents reduce efficiency and can cause overheating
• Monitor your heating bills — A sudden increase often signals a system issue

Annual Professional Maintenance

Once a year — ideally in fall for heating systems and spring for cooling — schedule a professional tune-up. A thorough tune-up includes:

• Cleaning burners and heat exchanger (furnace)
• Checking and adjusting gas pressure
• Testing safety controls and limit switches
• Lubricating moving parts
• Checking electrical connections and controls
• Measuring system performance against manufacturer specs
• Identifying any components showing wear

Annual maintenance typically costs $80–$150 and can prevent repairs that cost 5–10 times as much.

Heat Pump Maintenance

Heat pumps serve as both heater and air conditioner, so they need maintenance twice a year — once in fall and once in spring. The checklist is similar to the above, with the addition of:

• Checking refrigerant charge
• Inspecting the reversing valve
• Cleaning both indoor and outdoor coils

When to Call a Professional

Any time you notice reduced performance, unusual noises, higher bills, or visible issues (ice on the unit, water leaks, yellow flame), call a technician. Catching problems early almost always means a smaller repair bill.

We offer a $69 diagnostic that covers a full system inspection. Call 425-610-6635 to schedule — we're available Monday through Sunday, 6am to 5pm.