AC Coil Cleaning in Toronto and the GTA

AC coil cleaning removes the dust, hair and grime matted onto your air conditioner’s coil, so air can pass through it freely and the system can cool the house the way it should. Comfort Clean cleans the indoor evaporator coil, the one that sits on top of the furnace, and it is one of the services you can add to a spring duct cleaning visit anywhere in Toronto and the GTA.

We clean; we do not repair. Refrigerant, leaks, parts and an AC that will not cool are work for a licensed HVAC technician, and we say so up front. AC coil cleaning is priced by quote, and we have been family run since 1980.

Evaporator coil vs condenser coil

A central air conditioner in a GTA house has two coils, one inside and one outside, joined by a pair of copper refrigerant lines.

• The evaporator coil is indoors, in a metal box sitting on top of the furnace, and is usually shaped like an A. The furnace blower pushes house air through it, the cold coil pulls heat and moisture out of that air, and the moisture drips into a drain pan and out through a condensate line.
• The condenser coil is the outdoor unit beside the house: the wraparound metal fins with a large fan on top. It releases the heat taken out of the house into the outdoor air.

Both coils need air to move freely across thin aluminum fins. When dust mats the indoor coil or debris packs the outdoor one, the system cools less and runs longer to make up for it.

The indoor coil gets dirty in its own way. It is wet all summer, so dust that slips past the filter sticks to it and builds into a felt-like layer on the side where the air comes in. That layer is what most people mean by a dirty AC coil, and it is the one homeowners cannot easily reach.

Signs of a dirty AC coil

These are the signs we hear about most once the cooling season starts:

• Weak cooling: the AC runs, but the house never gets down to the setting on a hot afternoon
• Weak airflow from the vents, even with a clean filter
• Ice on the indoor coil, or on the larger copper line at the furnace or the outdoor unit
• A musty, damp smell when the AC starts up
• Water around the base of the furnace after the coil has iced up and thawed
• Longer run times and a higher hydro bill than last summer, in similar weather
• A grey, matted layer you can see on the coil when the access panel is off

Ice needs a careful response. Turn the cooling off at the thermostat, leave the fan running to help it thaw, and check the filter. A coil that ices up again after the filter and the coil are clean can point to low refrigerant or another fault, and that needs a licensed HVAC technician.

None of these signs is proof on its own. Weak cooling can also come from a refrigerant leak, a failing part, an undersized system or a hot attic. When our technicians open the coil box, they photograph what they find and tell you plainly whether a cleaning is likely to help.

Why AC coils get dirty in GTA homes

The indoor coil catches whatever the filter misses, and the outdoor coil catches whatever blows around the yard. The causes we see most:

• Filters: a missing filter, the wrong size leaving gaps at the edges, or one left in so long it collapses lets dust straight through to the coil
• Dirty ducts and blower: the coil sits right above the blower, so dust in the return and on the blower wheel ends up on it
• Pets and renovations: pet hair and fine drywall dust slip past many filters and stick to a wet coil
• Cottonwood: in late spring and early summer, cottonwood fluff drifts through many GTA neighbourhoods and plasters the fins of outdoor units
• Leaves, grass clippings and dryer lint: the outdoor unit pulls them in, especially when it sits next to a lawn, a hedge or the dryer vent
• Age: a coil that has never been cleaned carries years of buildup

The wet surface is why indoor coils mat up so fast. Dry dust might blow through, but on a coil that runs with condensation all summer it sticks, and every season adds a layer.

What we clean during AC coil cleaning

Our technicians clean the indoor evaporator coil and the area around it. On a typical visit we:

• Inspect the coil through the coil box access panel and photograph its condition
• Clean the dust layer off the coil face with a coil-safe cleaner and careful brushing, keeping the fins straight
• Vacuum up the loosened debris with negative-pressure equipment, so it is not pushed further into the system
• Look at the drain pan and the condensate line, and tell you about rust, cracks or standing water
• Take before-and-after photos

Access is the honest catch with indoor coils. Many coil boxes have an access panel, but some are sealed, and reaching the coil face would mean disconnecting refrigerant lines or cutting into the ductwork. We do neither. In that case we clean what we can reach safely and show you, with photos, what is left.

We clean the outdoor condenser coil too. We clear leaves, cottonwood fluff and grass clippings out of the unit, clean the fins gently so they stay straight, and take before-and-after photos, so both coils can be done in the same visit. Between our cleanings, the simple upkeep covered below keeps the outdoor unit in good shape.

The coil and the blower work as a pair. A clean coil above a dusty blower wheel gets coated again within a season, so we suggest cleaning them together. The furnace blower compartment is cleaned on our Luxury duct cleaning package, and blower and fan cleaning can also be added by quote.

Spring is the best time for AC coil cleaning

The best time is spring, before you switch the air conditioner on. In the GTA that usually means April or May, ahead of the first hot, humid stretch. The furnace has just finished months of pushing air through the system, and the coil is still carrying whatever stuck to it last summer.

Cleaning then means the AC starts the season with clear airflow, instead of running a matted coil through July heat. Spring is also when dates are easiest to get; once the first heat wave arrives, the calendar fills quickly.

The coil is worth doing on the same visit as your AC duct cleaning, because the ducts, the blower and the coil are one air path. Clean ducts behind a dirty coil, or a clean coil above a dusty blower, is half a job.

A fall cleaning, after the cooling season, also works, especially when the AC smelled musty over the summer.

Cleaning AC coils yourself: what is safe

Between professional cleanings, you can look after the outdoor unit yourself, as long as you are careful:

• Turn the power off at the outdoor disconnect box and set the thermostat to off before you touch it
• Clear leaves, cottonwood fluff, grass and twigs from around the base and off the fins by hand or with a soft brush
• Rinse the fins gently with a garden hose on a normal spray, working from the top down
• Never use a pressure washer: it flattens the fins and drives debris deeper into the coil
• Never bend, pry or scrape the fins with a screwdriver or a stiff brush, because bent fins block airflow just like dirt
• Keep plants, fences and stored items a couple of feet back from the unit

Foaming coil cleaners from hardware stores are made for this job, and some homeowners use them on the outdoor coil. Use one only as the label directs, rinse it off fully, and keep it away from the fan motor and the electrical parts.

Indoors, your part is the filter. CMHC advises checking the furnace filter monthly during the heating season, and keeping the same habit through the summer protects the coil, because cooled air passes through the filter on its way to the blower. Use the right size so air cannot slip around the edges.

The indoor coil itself is a different matter. Reaching it means opening a sealed coil box next to the refrigerant lines and wiring, and cleaner sprayed into a coil you cannot see can wash dirt into the drain pan and clog the condensate line. Household cleaners, bleach and degreasers do not belong in the coil box at all. That job is best left to us or your HVAC technician.

Refrigerant, repairs and what goes to an HVAC technician

We are a cleaning company, and we would rather you call the right people the first time. We do not:

• Handle refrigerant, recharge a system or find and fix refrigerant leaks
• Repair, replace or install coils, condensers, fan motors, thermostats or any other AC part
• Diagnose why an air conditioner will not cool or keeps tripping a breaker
• Repair drain pans, condensate pumps or drain lines
• Clean ductless mini-splits, window units or car air conditioners

When our technicians see oily stains on the coil, which often mark a refrigerant leak, or a cracked drain pan, a rusted coil box or ice that keeps coming back, they point it out and photograph it so you can show your HVAC company. A spring tune-up from a licensed technician and a coil cleaning from us work well side by side; one does not replace the other.

AC coil cleaning prices and booking

AC coil cleaning is an additional service, priced by quote. It is not part of any of our air duct cleaning packages, and the price depends on how the coil is installed, how easy it is to reach and how dirty it is. We confirm the total by phone before we book.

Most homeowners add it to a duct cleaning visit. Our posted duct cleaning packages are:

• Basic, $329, up to 10 vents: the supply side, from the furnace supply connection through the supply lines and supply main.
• Comfort, $399, up to 10 vents: the supply and return sides, plus the J-channel.
• Luxury, $499, up to 15 vents: the furnace blower compartment cleaned and the ductwork sanitized with a natural product (Benefect), on top of everything in Comfort.

Every package includes before-and-after photos, extra vents are $12 each, and there is no trip fee inside our service area. The full breakdown is on our duct cleaning prices page.

Condo suites run on a fan coil instead of a furnace and central air, and we clean the coil area, the filter housing and the short runs there as part of condo duct cleaning.

Our office is at Bathurst and Finch in North York, a short drive from Richmond Hill, Thornhill and Vaughan, and we also cover Mississauga and the rest of Toronto and the GTA. Call 905-738-1878 in early spring for the widest choice of dates.