Oshawa’s housing stock spans everything from post-war bungalows in Lakeview and O’Neill to newer builds in Kedron and Taunton, and the age and layout of a home changes what an A/C system needs to do its job properly. David Cassar serves all of Oshawa and Durham Region, available for same-day and emergency appointments when your cooling can’t wait.
From a first-time installation to an emergency repair on the hottest day of the year, David handles every job personally.
David sizes every new system using a proper load calculation, not a guess based on square footage. Oshawa’s older semi-detached homes in Centennial and O’Neill often have undersized duct runs that need to be assessed before any equipment goes in. You get a quote before anything’s ordered, and the price on paper is the price on the invoice.
David diagnoses the problem before quoting a fix. If a capacitor or contactor is the issue, he stocks common parts and can often repair it the same visit. He won’t tell you the compressor’s dead if it isn’t, and he won’t recommend a new unit to avoid a repair that costs a fraction of the price.
When a repair genuinely doesn’t make sense, David’ll walk you through your replacement options without pushing the highest-margin unit on the shelf. He selects equipment that matches your home’s duct system and your cooling load, not whatever’s easiest to install. Most replacements in Oshawa are completed in a single day.
A spring tune-up lets David catch failing capacitors, low refrigerant, and dirty coils before they strand you on a 35-degree afternoon. He checks refrigerant charge, cleans the condenser coil, inspects electrical connections, and confirms the system’s pulling its rated efficiency. Most tune-ups take under an hour and the cost is a small fraction of an emergency repair bill.
Upgrading from a 13 SEER unit to a 16 or 18 SEER system cuts your cooling costs measurably over a Durham Region summer. David’ll tell you honestly what payback period looks like for your home and your usage, so you can decide whether the upgrade makes financial sense right now or whether you’re better off running what you’ve got a little longer.
When your A/C stops working in the middle of a July heat wave, you’re not reaching a call centre when you call Cassar. David picks up and, if he’s available, he can often be at an Oshawa address the same day. He covers all of Oshawa’s neighbourhoods including Northwood, Pinecrest, McLaughlin, and Samac.
I’ve been working on air conditioners in Oshawa since 2011, and I’ve seen the full range of what’s out there, from 1960s bungalows in Lakeview running on ductwork that was never meant for central cooling, to newer Kedron subdivisions where the builder’s base-spec equipment is already showing wear after eight or ten summers. When you call me, I pick up. When I come out, I tell you what I actually found.
A central air conditioner in Ontario typically lasts between 15 and 20 years, though that range has a lot of asterisks attached to it. A unit that’s been serviced annually and runs in a well-shaded location on the north or east side of the house will often hit 20 years without major drama. The same unit running hard against a south-facing brick wall in full sun, with a dirty filter and no maintenance, might start struggling at 12.
In Ontario’s climate specifically, the shoulder seasons matter. A unit that gets turned on for the first time in May after sitting idle all winter without a spring check-up is absorbing a lot of stress. Refrigerant charge drifts, capacitors weaken over time, and condenser coils collect debris through fall and winter. Catching those things in a 45-minute tune-up before the season starts is the single biggest thing you can do to extend a system’s life.
If your unit is between 12 and 15 years old and you’re facing a repair over $800, that’s the moment to have an honest conversation about whether repair or replacement makes more sense. It’s not always replace, but it’s worth doing the math rather than defaulting to whichever option costs less today.
A basic central A/C repair in Oshawa, covering a common component like a capacitor, contactor, or fan motor, typically runs between $200 and $550 including labour. Refrigerant recharges vary because the cost of refrigerant changes and the amount needed depends on the leak and the system size. Expect $300 to $700 for a refrigerant service call depending on what’s involved.
New installations range more widely. A standard single-stage 13 to 14 SEER central air conditioner installed in an Oshawa home with existing ductwork usually comes in between $3,200 and $4,800, fully installed. A higher-efficiency two-stage or variable-speed unit at 18 SEER or above will run $5,000 to $7,500 depending on equipment selection and any ductwork adjustments required. Annual tune-ups typically cost $120 to $180.
What drives variation is the condition of the existing ductwork, accessibility of the indoor unit, refrigerant type the system uses, and the efficiency tier of the equipment chosen. Every job David quotes gets a written price before work starts. The best way to know what your specific job will cost is to get a free quote from David, no pressure, no obligation.
Oshawa’s housing stock is one of the more varied in Durham Region. The city has a large number of homes built between the 1940s and 1970s, particularly in the older south-end neighbourhoods like Lakeview, O’Neill, and Central Oshawa. Many of those homes were built with forced-air furnaces but no intent for central air conditioning, which means the ductwork is often sized for heating loads only. Adding a central A/C to one of these homes without reviewing the duct sizing can result in a system that short-cycles, doesn’t distribute air evenly, or runs well above its rated static pressure.
The newer subdivisions in the north end, including Kedron, Taunton, and parts of Windfields, generally have ductwork designed for cooling. But the builder-grade equipment installed in those homes from the mid-2000s onward is now aging into the replacement window. David sees a consistent stream of calls from homeowners in those areas whose 14 or 15-year-old builder-spec units are either failing or running so inefficiently that the hydro bills have become a problem.
Oshawa also has a significant number of semi-detached and townhome properties where the outdoor condenser placement is constrained by lot lines and fencing. Condenser clearance requirements need to be met regardless of how tight the space is, and cutting corners on placement is something David won’t do. If a pad relocation or line set extension is needed to do the job correctly, that’s what gets quoted.
The most common warning sign homeowners call about is an A/C that runs continuously but never quite reaches the set temperature. That symptom usually points to one of three things: a refrigerant leak reducing the system’s capacity, a dirty evaporator coil restricting heat exchange, or a duct leak bleeding conditioned air into an unconditioned space. In Oshawa’s older homes with flex duct or original sheet metal runs, duct leakage is more common than most homeowners realize.
Ice forming on the refrigerant line or on the outdoor unit in summer is another one worth calling about promptly. It looks like the system’s working hard, but it actually means airflow is severely restricted or refrigerant charge is off. Letting an iced unit keep running damages the compressor, and compressor replacement is where a repair bill crosses into replacement territory.
A unit that’s cycling on and off every few minutes rather than completing full cooling cycles is short-cycling, and it’s wearing out the compressor faster than normal operation would. Unusual noises, grinding, rattling or a loud bang on startup, all warrant a call before they become a larger repair. Catching these things early in the season, before a Durham Region heat warning pushes every HVAC contractor in the region into emergency mode, gives you more options and more time.
Durham Region’s summers run hot and humid, with humidex values regularly hitting the 38 to 42 degree range during July and August heat events. A properly maintained system handles that load without issue. One that’s even slightly low on refrigerant or running with a dirty coil will struggle to keep up when it matters most, and that’s when most repair calls happen.
Keeping your filter changed every 60 to 90 days during the cooling season is the most impactful thing you can do between service visits. A clogged filter drops airflow across the evaporator coil, which drops the system’s ability to remove heat from your home. Keeping the condenser unit clear of overgrown shrubs and debris helps it reject heat efficiently. Ontario’s spring windstorms and cottonwood season push a surprising amount of debris into condenser fins.
Setting your thermostat to hold temperature rather than letting the house swing wide and then blasting the A/C to recover also extends equipment life and reduces hydro costs. Programmable and smart thermostats that pre-cool the home before peak hydro rate periods are a practical option for most Oshawa homeowners and cost little to install alongside a new or existing system.
Central air conditioning in Ontario is regulated under the TSSA’s refrigeration code, which requires that anyone handling refrigerant hold a valid licence. TSSA Licence #000398183 covers David’s work on every A/C job in Oshawa. It’s verifiable through the TSSA’s public registry. When you hire an unlicensed technician, there’s no recourse if the work causes damage or a safety issue, and your home insurance may not cover it either.
Ontario’s Enbridge and Hydro One rebate programs have changed over recent years, but the Canada Greener Homes Grant and provincial programs have at various points covered upgrades to high-efficiency air conditioning and heat pump systems. Eligibility and available amounts shift, so David’ll point you toward whatever’s current when you’re considering a replacement. High-efficiency equipment that qualifies for a rebate can reduce the effective cost of an upgrade meaningfully.
On the efficiency side, Canada’s minimum SEER standard moved to 13 SEER for new equipment, but that’s a floor, not a target. For a home that runs the A/C four to five months of the year in Durham Region’s climate, the payback on a 16 or 18 SEER system over a 13 SEER baseline is real and worth calculating before you default to the cheapest option. David’ll run those numbers with you as part of a quote.
Checking the simple things before calling saves time for everyone, start here before picking up the phone.
Make sure it’s set to Cool and the temperature is set below current room temperature. Check the batteries too, a weak battery causes erratic thermostat behaviour that looks like an A/C problem but isn’t.
Your AC has a breaker in the main panel and an exterior disconnect box next to the outdoor unit. Check both are on. A tripped breaker that keeps tripping after reset points to an electrical fault, call David at that point rather than resetting it again.
A clogged filter blocks airflow and causes the evaporator coil to ice up, completely stopping cooling. Replace the filter and let the unit thaw for an hour before restarting. If the coil ices up again after a fresh filter, there’s a refrigerant or airflow issue that needs a technician.
The condenser unit outside needs clear airflow. Remove any debris, overgrowth, or objects within 60cm of the unit. Don’t hose it down while it’s running. If the fan on top isn’t spinning when the unit’s on, that’s a component failure, shut it off and call.
Closed vents create pressure imbalances that reduce cooling and can damage the system. Make sure every supply vent in the home is open. Closing vents to redirect airflow is a common misconception, it increases static pressure across the system and shortens equipment life.
If none of the above resolved it, the problem needs a licensed technician. David serves all of Oshawa and Durham Region and picks up the phone himself.
Once a year, in spring before the cooling season starts, is the right schedule for most Oshawa homes. That timing lets David check refrigerant charge, clean the condenser coil, test capacitors and contactors, verify electrical connections, and confirm the system’s ready to handle a Durham Region summer before the first heat event hits. Capacitors in particular degrade over time and often fail on the first hot day of the season, when the unit is under maximum load after sitting idle all winter. Catching a weak capacitor in a May tune-up costs a fraction of what an emergency call in July costs. If your home has pets or anyone with allergies, changing the filter every 60 days during the cooling season adds meaningful protection on top of the annual service. Skipping annual maintenance doesn’t just risk a breakdown. It shortens the overall life of the system and often voids equipment warranties. Most manufacturers require documented annual maintenance to honour warranty claims on compressors and coils.
There are five common reasons an A/C runs but doesn’t cool properly, and the right answer depends on which one applies. Low refrigerant from a leak reduces the system’s heat absorption capacity and is one of the most frequent causes. A dirty evaporator coil, often caused by running without a filter or with a badly clogged one, creates an insulating layer that prevents heat transfer. A failing condenser fan motor means the outdoor unit can’t reject heat effectively. Duct leakage bleeds cooled air into attics, crawlspaces, or wall cavities before it reaches the living space. And an undersized system for the home’s actual cooling load will simply never catch up on a hot day regardless of how well it’s maintained. In Oshawa’s older homes, duct leakage is something David checks on repair calls because it’s frequently overlooked by other technicians who focus only on the equipment. Before replacing a unit that “isn’t keeping up,” it’s worth ruling out a duct issue that costs far less to address.
A standard central air conditioner replacement on an Oshawa home with existing ductwork and a compatible furnace typically takes three to five hours from start to finish. That includes removing and disposing of the old outdoor and indoor coil units, installing the new equipment, making refrigerant line connections, pressure testing and evacuating the system, charging it to the manufacturer’s specification, and confirming it’s running at rated performance before David leaves. A first-time installation on a home that has never had central air adds time because the refrigerant lines need to be run from scratch and the air handler or furnace coil cabinet needs to be fitted. That typically takes a full day. If ductwork modifications are needed, it depends on the scope. Most duct adjustments David encounters in Oshawa, adding a return air grille or resizing a supply trunk, add a half day to a day. You’ll know exactly what’s involved before the job starts because David quotes the full scope upfront.
The honest answer depends on four things: the age of the unit, the cost of the repair, the efficiency of the existing system, and whether there are underlying issues like duct problems that a new unit won’t fix on its own. As a general rule, if the unit is under 10 years old and the repair is under $600, repair almost always makes sense. If the unit is over 15 years old and you’re looking at a compressor replacement or a refrigerant leak in a system running on R-22, replacement is usually the better financial decision because you’re putting significant money into equipment that’s at the end of its reliable life. The zone in the middle, 10 to 15 years old with a mid-range repair, is where the math actually matters. David’ll give you the honest comparison: what the repair costs now, what you’d likely spend over the next three to five years keeping the old unit running, and what a replacement would cost and save. He won’t push you toward replacement if repair makes more sense for your situation.
For most Durham Region homes, a 16 SEER system hits the sweet spot between upfront cost and operating savings. Canada’s minimum standard for new equipment is 13 SEER, which meets the legal requirement but leaves money on the table given how many cooling hours a Durham Region home accumulates between May and September. A 16 SEER unit uses roughly 20 percent less electricity than a 13 SEER unit running the same number of hours, and the incremental cost at installation is usually $500 to $1,000, which the efficiency savings typically recover within four to six cooling seasons. Going above 18 SEER makes the most financial sense for larger homes with high cooling loads or homeowners planning to stay in the property for 15-plus years. Two-stage and variable-speed units at higher SEER ratings also dehumidify more effectively than single-stage units, which matters during humid Ontario summers. David’ll walk through the numbers specific to your home’s size and usage before you decide on equipment tier.
When the system runs but doesn’t produce cold air, the most likely causes are low refrigerant charge, a frozen evaporator coil, a failed condenser fan motor, or a dirty condenser coil that can’t reject heat. Start by checking your air filter. If it’s clogged, replace it, turn the system to fan-only mode for an hour to thaw any ice on the indoor coil, then restart on cooling. If that doesn’t restore cooling, the issue is inside the system and needs a technician to diagnose properly. In Oshawa specifically, David also checks for condenser coil fouling caused by cottonwood and airborne debris, which is common on units near mature trees or grassy areas. A clogged condenser coil looks fine visually from the outside but can reduce cooling capacity by 20 to 30 percent. Cleaning it restores performance without any parts replacement. Don’t run a system that’s producing no cooling for extended periods. A compressor running under low-refrigerant conditions or against a seized condenser fan can fail permanently within hours.
Yes. David works on all major residential air conditioner brands including Carrier, Lennox, Trane, York, Goodman, Daikin, Bryant, Rheem, and Amana, among others. The diagnostic process for a refrigerant leak or a failed capacitor is the same regardless of whose name is on the cabinet. David stocks the most common capacitor and contactor sizes for frequent brands, which lets him complete many repairs on the first visit rather than ordering parts and returning. For less common brands or older units with discontinued parts, he’ll source what’s needed and tell you the lead time before you commit to the repair. The one situation where brand matters most is for warranty repairs on equipment still under the manufacturer’s coverage. David’ll confirm what’s covered before starting work so you don’t pay out of pocket for something the manufacturer should cover. If you’re not sure what brand you have or how old it is, the data plate on the outdoor unit has everything needed to look it up.
Yes, financing options are available for AC installation in Durham Region. The Enbridge Home Efficiency Rebate program and the Canada Greener Homes initiative have both offered financing components alongside their rebate programs, and HVAC-specific financing through third-party lenders is available for qualified homeowners. A new central air conditioner installation in Oshawa typically runs between $3,200 and $7,500 depending on equipment and scope, and spreading that cost over 12 to 60 months makes a high-efficiency unit accessible without depleting savings. David’ll go over current financing options when he provides your quote, including what programs are active at the time and what the approval process looks like. There’s no obligation to finance, and the quote David gives you is the same regardless of how you plan to pay. The best way to know what your specific job will cost is to get a free quote from David, no pressure, no obligation.
“Our A/C stopped blowing cold air on a Thursday afternoon in July. David came out to our Oshawa home the same evening and had it running again within the hour, turned out to be a failed capacitor.”
“I’d been told by another company that I needed a full replacement. David came out, looked at the system, and told me the compressor was fine and the real issue was a refrigerant leak at a fitting that he could repair. He fixed it that visit and the system’s been running great since. I appreciated that he explained what he found before quoting anything.”
“Replaced our old central air unit in our north Oshawa home last spring. The price David quoted was exactly what we paid, no add-ons at the end. He was careful with the floors, covered everything before he started, and cleaned up completely before leaving. Straightforward from start to finish.”
David covers all of Durham Region, click your community for local service information.
Same-day service available. TSSA certified. Honest pricing. Call or book online.
