MaintainlySeasonal
How often should you check your AC before summer?
AC seasonal startup check once a year. The commonly recommended range is annually (spring). A spring check catches issues before the first heatwave. It is seasonal work, best done in spring.
The pre-season check is the homeowner half of getting cooling ready: the things you can do yourself before deciding whether you also need a technician. Doing it in spring rather than during the first heatwave is the entire point, because that is when contractors are available.
Why does checking your AC before summer matter?
A spring check catches issues before the first heatwave.
What happens if you skip checking your AC before summer?
Discovering a fault during the first genuinely hot week means joining a queue behind everyone else who discovered theirs on the same day. Running a system with a blocked condenser or a low charge also stresses the compressor, which is the one component whose failure usually means replacing the whole outdoor unit.
How do you do it?
- Change the filter first. Everything else depends on airflow. Start here.
- Clear the area around the outdoor unit. Remove leaves, cut back vegetation, and leave at least half a metre of clear space all round for airflow.
- Remove any winter cover. A cover left on will destroy the unit within minutes of it starting. Check before switching on.
- Gently wash the condenser fins. Power off at the isolator first. Rinse from the inside outward with a garden hose at normal pressure. Never use a pressure washer, which flattens the fins.
- Straighten bent fins if needed. A fin comb restores airflow through areas that have been knocked.
- Check and clear the condensate drain. Flush the drain line and confirm it runs freely. A blocked drain on an attic air handler causes ceiling damage.
- Test it before you need it. Run cooling for fifteen minutes on a mild day. Check the air is genuinely cold, listen for unusual noise, and look for water where it should not be.
- Check the thermostat batteries and schedule. Trivial, and a common cause of a system that appears dead.
What does it take?
How do you know checking your AC before summer is overdue?
- Air from the vents that is cool rather than cold
- The outdoor unit running but the fan not turning, which usually means a failed capacitor
- Ice forming on the refrigerant lines
- Water pooling around the indoor unit
- A buzzing or humming outdoor unit that does not start
- Noticeably longer run times than last season
What do people get wrong?
- Leaving the winter cover on, which is a genuinely common and expensive error
- Pressure washing the condenser, which bends the fins closed and permanently reduces capacity
- Testing for the first time on the first hot day, when every contractor is booked out for a fortnight
- Running the system when the outdoor temperature is below about 15 degrees Celsius, which can damage the compressor on older units
What changes how often you need to do it?
- Coastal salt and heavy pollen both mean the condenser needs more attention
- Units under trees collect debris continuously and may need clearing several times a season
- Systems more than ten years old benefit from a professional check alongside the homeowner one
When should you stop and call someone?
Low refrigerant, a failed capacitor, electrical faults or ice formation all need a technician. Book in spring rather than waiting: the same job costs more and takes longer during a heatwave.
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Get the free appDoes this differ in the US, UK, Australia or Canada?
United States
Do it in March or April across most of the country, earlier in the South. Utilities in hot states frequently offer rebates for maintenance or for efficiency upgrades, and many contractors offer discounted spring service plans specifically to smooth their workload.
United Kingdom
Domestic air conditioning remains uncommon but is growing quickly as summers get hotter. Most installations are split systems, so the pre-season job is cleaning or washing the indoor unit filters, wiping the fins, and checking the outdoor unit is clear. Late spring is the moment, and demand for installers now spikes sharply during heatwaves.
Australia
Time this for September or October, before the summer. Reverse-cycle systems that have been used for heating through winter go straight into cooling duty, so the filter is already loaded. Coastal salt corrosion on outdoor units is a significant issue along the eastern seaboard, and a fresh water rinse of the condenser several times a year genuinely extends its life. Evaporative coolers, common in Perth and Adelaide, need pads checked and replaced and the water system flushed instead.
Canada
The cooling season is short, so it is efficient to combine the spring air conditioning check with the autumn furnace service as a single annual maintenance pattern. Remove winter covers and clear any remaining debris from the condenser after the thaw, and check the unit has not been damaged by ice falling from the roof.
Common questions
Why does checking your AC before summer matter?
A spring check catches issues before the first heatwave.
What happens if you skip checking your AC before summer?
A spring check catches issues before the first heatwave. Skipping it does not usually fail immediately, which is exactly why it gets forgotten: the consequence arrives months later as a repair bill rather than as an obvious fault.
Does checking your AC before summer differ by country?
US/CA central AC. UK split units less common.
When in the year is checking your AC before summer best done?
This is seasonal work. Plan it for spring, before the weather it protects against arrives.
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