How to Prep Your Air Conditioner for Summer

With over 60 years of keeping Canadian homes comfortable and more than 160,000 five-star user reviews on Google, Reliance Home Comfort^® knows a thing or two about getting your air conditioner ready for the season. In this episode of Ask Reliance, one of our licensed technicians walks you through the exact steps our team recommends before you flip the switch this summer.

What Our Technicians Check Before Every Cooling Season

When a Reliance technician arrives for a spring tune-up, these are the same steps they follow. Now you can tackle the basics yourself, and call us for the rest.

1. Clear the area around your outdoor unit

Our techs see this on almost every first visit of the season: condenser units buried under leaves, garden tools, or patio furniture. Keep at least 12 inches (30 cm) of clearance on all sides so your system can breathe. A blocked unit works harder, wears out faster, and costs you more to run.

2. Remove the winter cover

It sounds obvious, but our service team gets calls every spring from homeowners who turned on their AC without removing the cover first. Running a covered unit can overheat the compressor and lead to a repair that could have been avoided in seconds.

3. Clean the condenser coils the right way

This is where technique matters. Our technicians recommend rinsing the aluminium fins with a garden hose from the inside out. If you can only access the outside, use very low pressure, remove the nozzle, and spray at an angle. Pushing debris deeper into the coils is one of the most common DIY mistakes we see, and pressure washers are the number one culprit. Never use one on your condenser.

4. Check and replace your filter

A clogged filter is the single easiest thing to fix and the single most common reason for poor performance. Our techs recommend checking it every one to three months during the cooling season. If it looks dirty, swap it out. Your system and your air quality will thank you.

5. Switch your thermostat from heating to cooling

Set your thermostat to cooling mode and start around 22 °C to 25 °C. If your system has been off all winter, give it a few minutes to cycle before adjusting. If anything sounds or feels off, that is when you call us.

6. Book your annual Reliance tune-up

The steps above cover the basics, but there is no substitute for a professional inspection. A Reliance technician will check refrigerant levels, test electrical connections, inspect the blower motor, and catch small issues before they turn into mid-summer breakdowns. We offer 24/7 phone support and as-soon-as-same-day service so you are never left waiting in the heat.

Why Canadians Trust Reliance for AC Maintenance

Anyone can publish a summer AC checklist. The difference is that ours comes from the same licensed technicians who service thousands of homes across Canada every week, from Ontario to British Columbia. When you follow these steps, you are getting the same advice our team gives on the job, backed by decades of hands-on experience and a commitment to keeping you cool, calm, and comfortable.

Frequently Asked Questions

When should I turn on my air conditioner for the first time in summer?

Turn on your air conditioner once daytime temperatures consistently reach around 20 °C or higher. Before switching it on, complete the prep steps above to make sure the system is clean, uncovered, and ready to run safely.

How often should I replace my AC filter?

Check your filter every one to three months during the cooling season. Replace it when it looks visibly dirty or clogged. A clean filter improves airflow, efficiency, and indoor air quality. Learn how to change your filter here.

Can I pressure wash my AC condenser?

No. Never use a pressure washer on your condenser. High pressure can bend or damage the delicate aluminium fins. Use a garden hose on a low-pressure setting with no nozzle, and spray at an angle to gently rinse away dirt and debris.

What happens if I run my AC with the winter cover still on?

Running your air conditioner while the cover is still in place restricts airflow and can cause the system to overheat. This may lead to compressor damage or a complete system failure. Always remove the cover before turning the unit on.

How much clearance does my outdoor AC unit need?

Keep at least 12 inches (30 cm) of clear space on all sides of the outdoor unit. This allows proper airflow and helps the system cool efficiently. Trim back shrubs, move patio furniture, and clear away any stored items.

Is annual AC maintenance really necessary?

Yes. Annual maintenance helps catch small issues before they become costly repairs. A trained technician will clean the coils, check refrigerant levels, test electrical connections, and make sure your system is running at peak performance. Reliance Home Comfort offers annual maintenance plans with 24/7 support.

How do I know if my air conditioner needs repair instead of just maintenance?

Common signs your AC may need repair include unusual noises, warm air blowing from the vents, frequent cycling on and off, ice forming on the unit, or a noticeable increase in energy bills. If you notice any of these, Call on Reliance for as-soon-as-same-day service.