Quick answer
A central air conditioner should be serviced once a year, in spring before the first hot week. A heat pump that also heats needs two visits, spring and fall. Between visits, the homeowner's part is a filter change every one to three months and a rinse of the outdoor coil in June. Units past 10 years old, and houses on treed or lakeside lots, benefit from a closer eye.
How often an air conditioner should be serviced comes down to one professional visit a year for a central AC, plus a few small jobs you do yourself through the summer. The visit belongs in April or May, before the first 30°C stretch, because that is when a weak capacitor or a low charge shows up and when a service slot is still easy to book. What follows is what that interval actually involves, when it should be shorter, and what to skip.
Once a year for an AC, twice for a heat pump
A straight air conditioner works about four months of the year in Burlington, so a single spring tune-up covers it. A heat pump runs 12 months and defrosts through the winter, so it gets a spring visit for cooling mode and a fall visit for heating mode; the details are in how much heat pump maintenance costs. A ductless mini-split follows the same rule as whatever it is, AC or heat pump, with the addition of washing the indoor filters monthly.
What a yearly AC service should include
- Refrigerant charge checked by superheat or subcooling, with a leak search if it is low. A charge that is off by a small amount costs efficiency all summer.
- Capacitor tested in microfarads and the contactor inspected for pitting. These are the two parts that fail in heat waves, and both are cheap to replace on a scheduled visit.
- Compressor and fan motor amp draw compared with the nameplate, which catches a motor on its way out a season early.
- Outdoor coil cleaned with coil cleaner and rinsed from the inside out, with bent fins straightened.
- Indoor coil inspected and cleaned if there is biofilm, and the condensate pan, trap and line flushed; those are the two causes of a musty smell and a wet floor.
- Temperature drop across the indoor coil measured, typically in the range of 8–11°C when the system is healthy, and the thermostat checked against a reference thermometer.
- Electrical connections tightened at the disconnect and the unit, and the disconnect fuses checked.
That visit runs $120–$250 on its own. A maintenance plan bundling it with the fall furnace tune-up is $150–$350 a year and moves you to the front of the queue when the first heat wave floods the phones; whether that trade is worth it for you is examined in are HVAC maintenance plans worth it.
The jobs between visits are yours
- Filter: every one to three months, more often with pets or a renovation underway. A clogged filter freezes the coil and starves the blower.
- Cottonwood season: in June the poplar fluff mats the condenser coil within days, especially on lots backing onto Grindstone Creek in Aldershot or the Bronte Creek valley. A garden hose from the inside of the unit outward, with the power off, restores the airflow.
- Clearance: keep the cedars and the hostas 60 cm back from the cabinet and put nothing on top of it. A condenser that cannot dump heat runs its pressures up on exactly the days you need it.
- Watch the drain line: a drip at the outlet on a humid day means the drain is working.
- Fall: leave the unit uncovered or use a top-only cover so moisture is not trapped inside the cabinet over winter.
When the interval should be shorter
Annual is the floor, not the ceiling. An air conditioner past 10 years old is running on original parts that are in their failure years, and a mid-season check in July catches a capacitor that tested marginal in May. Houses on the lakeshore in Bronte and Roseland see more condensate and more corrosion from humid air; heavily treed lots see more coil fouling. If the unit was low on refrigerant last year, it has a leak, and a mid-summer pressure check tells you whether the repair held.
Warranty is the other reason. Some manufacturers' terms ask for evidence of regular maintenance when a major part is claimed, and the compressor is the part they ask about. Keeping the invoices from a yearly visit is the simplest way to protect that.
What you can skip
You do not need a refrigerant top-up every year; a system that needs one has a leak. You do not need duct cleaning on a schedule; it is a job for a reason, such as a renovation or a flood. And you do not need the outdoor unit serviced in the fall if it is a straight air conditioner, whatever the flyer says. A spring visit that does the list above, done every year, is the whole program for most homes.
ZK Mechanical books spring AC tune-ups from April across Burlington, Oakville and Hamilton, and the cost breakdown is in how much AC maintenance costs. To get on the spring list for Burlington air conditioning service, reserve a date online or phone the shop.