Definition: maintenance is preventive, not reactive
Every major home system has two failure paths: gradual degradation (loses efficiency, gets noisy, costs more to run) and sudden failure (no heat in January, basement flooding at 2 AM). Annual or semi-annual service catches the first before it becomes the second. It also typically pays back its own cost in energy savings + warranty preservation.
Manufacturer warranties almost universally require documented annual maintenance. Skip a year and a $4,000 compressor replacement under warranty becomes a $4,000 compressor replacement out of pocket.
When (and how often) for each system
Forced-air furnace — once per year, in fall
Annual fall tune-up: combustion analysis, heat exchanger inspection (carbon monoxide safety check), gas pressure check, burner flame inspection, blower motor amp draw, filter change. Belts and bearings on older units. A bad heat exchanger is a CO leak risk — never skip the fall tune-up if your furnace is over 12 years old.
Central AC or heat pump — once per year, in spring
Refrigerant charge check (a low-charge AC runs 30%+ longer to do the same cooling), condenser coil cleaning, capacitor + contactor inspection, drain line flush. Heat pumps additionally need their reversing valve cycled and defrost cycle verified. Skip a year and the refrigerant slowly leaks past schraders; skip three and your compressor burns out.
Tank water heater — once per year
Flush the tank to remove sediment (the #1 cause of early failure in hard-water areas like Walworth County), check anode rod (replace every 4–6 years or sooner with high TDS water), test T&P relief valve, inspect for any weeping at fittings. A tank flush takes 20 minutes; adds [verify: 3–5 years of life]. See also how softening extends water-heater life.
Tankless water heater — once per year
Descale (white vinegar or proprietary descaler) to remove calcium buildup on the heat exchanger. This is non-negotiable in hard-water areas. Skip it and your $3,000 tankless will throw an error code and fail by year 7 instead of lasting its rated 20+ years.
Water softener — check monthly, service annually
Monthly: visually check brine tank salt level; break up any salt bridge with a broom handle. Annually: full diagnostic — check resin bed condition, verify regeneration cycle timing, check valve seals, sanitize the brine tank. An overlooked salt bridge will silently stop a softener from regenerating for months — the unit runs but produces hard water.
Sump pump — test twice a year
Pour 5 gallons of water into the pit each spring and fall and watch the pump trigger and clear it. Check the check valve. Listen for a struggling bearing or odd cycle pattern. A primary sump pump lasts 7–10 years; a battery backup needs its battery replaced every 4–5 years. If your basement holds anything you can't replace, you need both.
Whole-house generator — once per year (mandatory) + monthly self-test
Monthly automatic self-test runs the engine briefly under no-load. Annually we do an oil + filter change, spark-plug check, battery load test, full transfer-switch exercise, and a 20–30 minute under-load run. A generator that hasn't been serviced is a generator that won't start on the night you need it — we see this every winter.
Electrical service panel — visual check every year, full inspection every 5 years
Visually check for any tripped breakers that won't reset, signs of arcing or scorching, loose covers, or anything warm to the touch. Every 5 years or after a major addition: full panel inspection with thermal imaging on all bus connections. Required after lightning strikes or significant surge events.
Failure modes: what happens when you skip
- Skip annual furnace tune-up → CO risk, voided warranty, ~20% efficiency loss.
- Skip annual AC tune-up → refrigerant loss, dirty coils, compressor burnout (the most expensive single AC repair).
- Skip water-heater flush → sediment buildup, burner overworks, tank rusts from bottom up, 30%+ early failure.
- Skip softener salt-bridge check → silent failure; you're paying for soft water and getting hard water.
- Skip sump pump test → flooded basement on the one night it mattered.
- Skip generator service → won't start when the grid goes down.
Proof: how the annual plan works
Our annual maintenance plan covers HVAC, plumbing, AND water-quality on one membership. Two scheduled visits a year (spring + fall), priority response on emergencies, and a discount on parts and any out-of-plan repairs. See the plan article for full details.
Action: what to do this season
- Request a single service visit if you're overdue.
- Enroll in the maintenance plan for both systems at once.
- Set a phone reminder: furnace in October, AC in April, sump pump in May and October.
