When Should You Service an Air Conditioner? A Yearly Plan and the Warranty Trap
An air conditioner sits in an odd place among household appliances: its faults only surface seasonally. Nobody notices a broken AC in November. They notice it in July — the same week every technician is fully booked.
That makes it the appliance where “call someone when it breaks” costs the most. It also has an interesting warranty trap, which I’ll come to.
The yearly plan: which job, when, by whom
| Job | Frequency | Who |
|---|---|---|
| Indoor unit filter cleaning | Every 2-4 weeks in heavy use | You |
| Outdoor unit fins and surroundings | Start of season | You |
| Drain line check | Start of season | You / technician |
| Full service, refrigerant pressure, electrics | Once a year, pre-season | Authorised service |
| Deep clean (indoor unit stripped) | Every 1-2 years | Technician |
The critical line is pre-season. Book in April or May and you get an appointment and can negotiate; call in July and you join a queue and accept whatever price you’re quoted.
The three things you can do yourself
1. Clean the filter. The most neglected and easiest job. A dirty filter does two things: reduces cooling and increases electricity use. Once a month, warm water, dry it fully before refitting.
2. Check the drain. If water drips from the indoor unit, it’s usually not a fault — it’s a blocked drain line. One of the things to check before calling anyone; the general list is in 6 things to do before you call a repair service.
3. Clear the outdoor unit. If the outdoor unit can’t breathe — boxed in, covered over, fins clogged with dust — the system strains and the compressor’s life shortens.
🔴 The warranty trap: “low on gas”
The most common sentence in AC repair: “it’s low on gas, let’s top it up.”
Here’s what to know: refrigerant doesn’t deplete on its own in a sealed system. If it’s low, there’s a leak. Topping up without finding the leak postpones the problem by one season and burns money.
The warranty trap sits right here: unauthorised work can, depending on the manufacturer, put your cover in dispute. Having “a guy you know” top up the gas while the unit is under warranty can make a later compressor claim much harder. If the unit is in warranty, the authorised service is the first address.
What to do in the final month of cover is in 5 things to do before your warranty expires — particularly relevant for AC, because the expiry usually falls in winter when nobody is thinking about it.
Why records matter here
Keeping records on an air conditioner has three concrete payoffs:
- Warranty: a claim is hard without the installation date and the invoice. The installation invoice is a separate document from the purchase invoice — you need both.
- Leak tracking: knowing “we topped it up two years ago as well” is what makes a technician look for the leak. Without records, the same gas gets refilled every year.
- Sale or moving: a documented maintenance history helps when the unit changes hands.
Duevo is built for exactly this: each device recorded with its warranty date, invoice and installation photos kept alongside, reminders before scheduled maintenance and before cover ends, and completed services logged into the history. A system that reminds you in May is what keeps you out of the July queue.
For the rest of the appliances in the house, see the appliance maintenance schedule.
Frequently Asked Questions
How many times a year does an AC need servicing? General rule: a full service once a year, before the season. Filter cleaning is your job and should be repeated every 2-4 weeks in heavy use. In dusty or heavy-duty environments, professional servicing can go to twice a year.
My AC isn’t cooling — does that mean it’s out of gas? No, and usually it isn’t. Check filter cleanliness, airflow to the outdoor unit and the settings first. If refrigerant genuinely is low, the cause is a leak; topping up without finding it is a temporary fix.
Will topping up the refrigerant myself void the warranty? Practice varies by manufacturer, but unauthorised work can put cover in dispute. If the unit is under warranty the authorised service is the right address; when in doubt, check the terms on the warranty document.