Durham Region HVAC Specialists
Durham Region
HVAC Contractor
- Fully Licensed & TSSA Certified
- 24/7 Emergency Service
- 20+ Years Experience
- Residential & Light Commercial
- No-Pressure, Free Quotes
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Installation & Repair
HVAC Installation & Repair in Durham Region
Durham Region’s Trusted HVAC Contractor
Cassar Heating and Air Conditioning has been the trusted HVAC contractor for Durham Region homeowners since 2011. Owner David Cassar spent nearly a decade in the industry before founding the company with a clear aim: professional workmanship at a fair price, every time.
We serve Oshawa, Whitby, Ajax, Pickering, Clarington, Bowmanville, Newcastle, Courtice and the surrounding communities. Whether you need a new furnace, an air conditioner, a heat pump or a hot water heater, we bring real hands-on experience to every job. No subcontractors. No shortcuts.
Quality You Can Trust
Every job is done right the first time. David and his team take pride in their work — from the first call through to the final test run, the standard doesn’t slip.
Excellent Customer Service
Honest advice, clear pricing, and calls returned the same day. Customers across Durham Region come back to Cassar because the service matches the workmanship.
We Take Pride in Our Work
TSSA licensed, fully insured, and accountable. No shortcuts, no subcontractors. When the van leaves your driveway, the job is done and the area is clean.
Our Happy Clients
What Durham Region Homeowners Say
Rated 5 stars across Durham Region
Great experience with David and team. From his patience in diagnosing the issue (thoughtful and thorough) to eventually replacing the furnace, the approach was top notch. Dave and Alex made the install as painless and seamless as possible. Highly recommended Cassar as the only choice for heating and air service.
Seriously I can’t say enough — reliable, best pricing, honest and just a genuinely nice guy. We were in a pinch and he installed our new furnace in a fraction of the time in a snow storm. I think he left the furnace area cleaner when he left than it was when he arrived. Truly recommend.
Dave and his team were exceptional from start to finish. Our furnace stopped working and needed some help quickly as it was quite cold. They treated my home as if it was his own, and took the time to thoroughly explain the issues and our options. Highly recommend Cassar Heating and AC.
Diagnosed and fixed my A/C unit over the phone with me at 10pm in about 15 minutes. When the other big companies charge over $100 just to show up before fixing the problem, David is an absolute boss. 11/10 would recommend.
We cannot thank David and his team enough for the work that they have done for us. The quality of work and their professionalism was second to none. It was so great to have this level of service, quality of care and experience at a price that was incredibly competitive. I cannot say enough and would highly recommend them.
I called David on a Sunday to help with a Nest thermostat install. He showed up in minutes, ran new wiring and got everything running, all for a great rate. 100% would recommend and use again.
Spectacular job from start to finish. Our coolant leaked because of the poor work of another contractor. David and his team were able to refill and actually lift the unit up off the ground. They left it in a better state than it ever was. Will definitely go to them for any future AC needs.
Great service! They were fast, efficient, and had great communication. Added bonus, it was nice to speak to an actual person instead of an automated message.
David did an outstanding job hooking up the gas to our new stove. To top it off he’s courteous and punctual. Will definitely be recommending him to friends and family.
David and his crew are professional, friendly and efficient. We are so happy with the work they provided and David’s expert advice. We definitely recommend this company.
David and Luca were very professional and answered all the questions we had. Provided great options for troubleshooting and adjusting our existing setup for better performance and a cleaner finish.
David has always provided great service and honest advice. Highly recommend.
HVAC Services Across Every Durham Region Community.
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