Service each system once a year: the furnace or boiler in fall and the AC in spring. A tune-up costs $70 to $200 by HomeGuide's national 2026 figures. Changing filters on time is the cheapest maintenance there is.
Price ranges on this page are national figures published by HomeGuide for 2026. They are not our quotes. Your house, the equipment you choose, the venting and the ductwork move the real number up or down. Last checked October 2026.
How often should I get my furnace serviced?
Get your furnace serviced once a year, in early fall before the first cold nights. In Detroit, booking in September or October avoids the rush that starts with the first hard freeze. Older furnaces, and homes with pets or dust, benefit the most.
Air conditioners should be serviced each spring, before the first hot stretch in June.
How much does a furnace tune-up cost?
A furnace tune-up costs $70 to $200, by HomeGuide's furnace repair page. Its HVAC inspection page lists a furnace tune-up at $150 to $500, so the pages disagree. An AC tune-up is listed at $70 to $200 with a national average of $120.
DTE Energy and Consumers Energy have offered tune-up rebates when a participating contractor does the work, and we are one. We check the current program when you book.
What is done during a tune-up?
During a furnace tune-up, the technician cleans and checks the parts that fail most and tests the safety controls. During an AC tune-up, the focus is the coils, refrigerant and electrical parts.
- Furnace: clean the flame sensor and burners, test the igniter, check gas pressure and the flame.
- Furnace: test the limit and pressure switches, check the venting and the heat exchanger, test for carbon monoxide.
- AC: clean the outdoor coil, check the refrigerant charge, test the capacitor and contactor.
- Both: check the blower, the filter, the thermostat and the condensate drain.
Are HVAC maintenance plans worth it?
A maintenance plan is worth it if you would not otherwise remember yearly service, or if your system is older. HomeGuide lists annual plans at $150 to $450 on its furnace page and $120 to $360 on its AC page, nationally.
Before signing, check what the plan includes: how many visits, whether parts or priority booking are covered, and whether it renews automatically. A plan that only covers one visit a year is mostly a scheduling reminder.
How often should I change my furnace filter?
Change a standard 1-inch filter every one to three months, and check it monthly in winter. Thicker 4 or 5 inch media filters often last six months to a year. Homes with pets, smokers or renovation dust need more frequent changes.
What happens if you never change the furnace filter?
If you never change the filter, the furnace starves for air. It overheats and trips its limit switch, short-cycles, runs up the gas bill and wears out the blower motor. On the AC side, a clogged filter is a common reason the coil freezes. A dirty filter can also let dust coat the coil and blower.
Do I need to cover my outdoor AC unit in winter?
No, you do not need to fully cover an outdoor AC unit in winter. A full wrap traps moisture and invites mice. A piece of plywood or a top-only cover can keep falling ice and leaves off the top. Never cover a heat pump, since it runs all winter.
Before winter, clear leaves and debris from around the unit and keep shrubs trimmed back.
Does skipping maintenance void my furnace warranty?
It can. Many manufacturer warranties ask for professional installation and regular maintenance, and a denied claim may point to a lack of service. Read your warranty, and keep receipts from every tune-up.
Snow is blocking the white pipes on the side of my house, or the condensate line froze. Is that a problem?
Yes. The white plastic pipes are the intake and exhaust for a high-efficiency furnace, and if snow or ice blocks them the furnace shuts off for safety. Gently clear the snow by hand. Do not hit the pipes.
A frozen condensate line also stops the furnace. It usually freezes where it runs outside or through a cold space. Thaw it with warm water, and have us reroute or protect it so it does not happen again.
The only way to get a real price for your home is an on-site visit and a written quote. Call or text (313) 488-2188.