HVAC Maintenance Checklist for New England Homeowners (Spring & Fall)

New England HVAC systems work harder than almost anywhere in the country. Your equipment has to run in both extremes — winter cold that can freeze pipes and summer humidity that strains cooling systems — often in a house that’s 80–120 years old.

This twice-yearly checklist comes from our service technicians who see what goes wrong when maintenance is skipped.

Fall Checklist (September – October)

Do this before you turn on the heat for the first time.

Boiler & Radiator System

• Schedule annual boiler tune-up: clean burners, check heat exchanger for cracks, test safety valves, verify combustion efficiency
• Bleed hot-water radiators: use a radiator key to release trapped air from each radiator (you’ll hear it hiss, then water follows — close the valve)
• Check boiler water level: should be at the marked level; low water can cause the low-water cutoff to shut the boiler down
• Inspect expansion tank: a waterlogged expansion tank causes pressure relief valve to drip
• Test all zone valves: turn each thermostat to call for heat and confirm the radiators in that zone actually get warm
• Check fuel supply (oil heat): order early; fuel prices spike and delivery delays happen in late October

Forced-Air Furnace

• Replace air filter (1-inch filters: every 1–3 months; 4-inch media filters: every 6–12 months)
• Clear around the furnace: 3-foot clearance from combustibles
• Inspect flue pipe for rust, disconnections, and blockages
• Test carbon monoxide detectors: replace batteries; replace units over 7 years old
• Check condensate drain (high-efficiency furnaces): clear the plastic drain tube; algae can block it

General

• Test thermostat: switch to heat mode, confirm it calls correctly
• Seal air leaks around ductwork with HVAC-rated foil tape (not regular duct tape)
• Stock one replacement filter so you’re not caught without one mid-winter

Spring Checklist (April – May)

Do this before the first hot stretch of the year.

Central Air Conditioning

• Schedule AC tune-up: clean evaporator and condenser coils, check refrigerant charge, test capacitors and contactors
• Clear the outdoor condenser unit: remove leaves, sticks, and overgrown vegetation; maintain 2-foot clearance on all sides
• Straighten bent condenser fins with a fin comb if needed
• Check condensate drain line: pour a cup of diluted bleach down the drain pan drain to prevent algae
• Replace air filter
• Test thermostat in cool mode: set to 65°F, confirm system runs and actually cools the supply air

Mini-Split Systems

• Wash filter panels (every 2–4 weeks during heavy use): most units have slide-out foam filters — rinse under water, dry before re-installing
• Inspect line set cover (exterior): UV exposure cracks plastic; replace if cracked to protect refrigerant lines
• Check drain hose at outdoor unit: should drip water during operation

General

• Test smoke and CO detectors — replace batteries
• Check for winter damage: inspect visible pipes for frost damage, look for condensation staining on ceilings that might indicate a frozen pipe leak that went unnoticed

Signs Your HVAC System Needs Professional Attention

Even with good maintenance, watch for these warning signs:

• Unusual noises: rattling, banging, squealing, or kettling
• Short cycling: the system turns on and off every few minutes
• Ice on the AC unit: sign of low refrigerant or blocked airflow
• Yellow pilot light or flame: potential CO hazard — call immediately
• Fuel bills up 20%+ year-over-year with similar usage

Boston Plumbing Solutions offers boiler tune-ups, AC service, and mini-split maintenance throughout Greater Boston. Our BPS Membership Plan includes two annual system checks at a discount.

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