Rooftop Unit (RTU) Repair & Installation

Rooftop Unit Repair & Installation in Uxbridge, ON

Family-Owned. Licensed. 7,000+ Units Serviced Across Durham & York.

When a rooftop unit fails, your business feels it immediately. Marx Mechanical Heating and Cooling is a family-owned HVAC company based in Uxbridge, and we’ve been servicing commercial properties across the Greater Durham and York Regions since 2017. With over 20 years of collective experience and more than 7,000 units serviced, we bring serious commercial HVAC credentials to every rooftop job, whether it’s a repair call, a full installation, or a scheduled maintenance visit.

Our RTU services cover the full scope of commercial needs: offices, retail plazas, restaurants, and warehouses. A rooftop unit is a self-contained HVAC system mounted on a building roof that integrates heating, cooling, and ventilation into a single cabinet, feeding into the building’s existing ductwork. It’s the standard commercial solution for low-rise buildings across Ontario, and keeping it running is critical to your operations, your staff, and your customers.

Ready to schedule a rooftop unit assessment or request a free estimate? Call our team today at (289) 301-0414. Same-day appointments are available, and we’re on call 24/7 for emergencies.

What Commercial Operators Get with Marx Mechanical Heating and Cooling

We built our reputation on what we call the Marx Promise: a service approach that balances cost, efficiency, and reliability. That means transparent upfront pricing, no hidden fees, and honest recommendations, whether that points toward a repair or a full replacement. Free estimates are available on all RTU repair and installation projects with no upfront commitment.

Our licensed technicians hold the qualifications Ontario law requires for commercial rooftop work, including TSSA gas technician certification for gas-fired components and a Skilled Trades Ontario 313A Certificate of Qualification for refrigeration and air conditioning. As a Daikin Comfort Pro Partner, we have direct access to Daikin commercial package units backed by robust manufacturer warranties.

Financing is available through Financeit for qualifying RTU installations and replacements. For businesses that want proactive protection, the Marx Comfort Club membership delivers priority service scheduling, discounted repairs, and regular maintenance visits. When something goes wrong outside business hours, our 24/7 emergency response means you’re not waiting until morning.

Common RTU Problems & When to Call for Repairs

Rooftop units fail in predictable ways, and catching the warning signs early is the difference between a repair call and a shutdown. Common failure points include compressor problems, refrigerant leaks, blower motor failures, electrical control board faults, clogged filters, and dirty coils. Any one of these can degrade performance well before the unit stops working entirely.

Watch for these signals in your commercial space:

Rising energy bills without a change in usage patterns
Uneven heating or cooling across different zones in the building
Unusual noises such as grinding, clanging, or rattling from the rooftop cabinet
Frequent short-cycling where the unit starts and stops in short bursts
Declining indoor air quality or excessive dust and humidity complaints from occupants

In high-traffic commercial spaces, RTU filters typically need replacement every one to three months to prevent blower motor strain. If an Ontario technician issues a red tag on your unit, the system has been flagged as unsafe or in need of repair before continued use. A Type A red tag means an immediate danger has been found and the gas supply is shut off. A Type B red tag means no immediate danger exists, but the deficiency must be corrected by the expiry date on the tag. Either type requires prompt professional attention.

Repairing vs. Replacing a Commercial Rooftop Unit

Not every RTU problem calls for replacement, but some do. A well-maintained commercial HVAC system typically has a service life of 15 to 20 years. Consistent seasonal maintenance helps a unit reach the upper end of that range. Neglect tends to shorten it considerably.

As a general guide, an RTU more than 15 years old that requires repeated repairs is a replacement candidate. When projected repair costs approach a significant portion of what a comparable new unit would cost, replacement with a high-efficiency model is typically the more practical financial decision. Modern high-efficiency rooftop units offer lower energy consumption, quieter operation, and improved air quality compared to equipment that’s past its prime.

Ontario businesses that upgrade to qualifying high-efficiency rooftop units may be eligible for financial incentives through SaveOnEnergy.ca, administered by the IESO. Program terms, eligibility requirements, and rebate amounts change periodically, so we recommend confirming current availability when you’re planning a replacement. We can walk you through equipment options and help you understand what may apply to your facility.

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Getting Started in Simple

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Areas We serve

Providing service to Uxbridge, Ontario and other surrounding areas.

Ajax
Aurora
East Gwillimbury
Georgina
Kawartha Lakes
Newmarket
Oshawa
Pickering
Port Perry
Whitby
Whitchurch-Stouffville

RTU Installation for Uxbridge & Durham/York Commercial Properties

Installing a commercial rooftop unit is more involved than swapping equipment. Proper sizing requires a load calculation based on building square footage, insulation, occupancy levels, and ventilation requirements. An undersized unit struggles to keep up with demand; an oversized unit short-cycles and wears out faster. We assess both before recommending anything.

Permits, Compliance & Pre-Installation Assessment

Before installation begins, we evaluate roof integrity and weight capacity, confirm curb adapter compatibility when replacing an existing unit, and account for applicable Ontario Building Code requirements. Installations typically require a TSSA gas permit and may require a municipal building permit depending on project scope. We manage that process so you don’t have to.

Design, Equipment & Commissioning

Our design and build capability includes custom duct layouts, thermostat and control strategy configuration, and air filtration integration. We walk every commercial client through equipment options and future expansion considerations so the system can support where the business is going, not just where it is today. As a Daikin Comfort Pro Partner, we have direct access to Daikin commercial package units suited to a range of rooftop applications.

Built for Ontario Winters: RTU Service Across the Region

Ontario’s climate is hard on rooftop equipment. Cold winters bring snow loads, ice formation, and sustained low temperatures that stress cabinet seals, controls, and heat exchangers. Durable weatherproof equipment and consistent seasonal maintenance aren’t optional for commercial operators in the Durham and York region. They’re important for keeping the system running when the weather turns.

We serve offices, retail plazas, restaurants, and warehouses throughout Uxbridge and the surrounding townships. Restaurants and commercial kitchens have additional makeup air requirements that differ from standard commercial configurations, and our team accounts for those demands during both installation design and repair assessments. When you work with us, you’re working with a team based in this community, not dispatched from the GTA.

Commercial RTU Maintenance & the Marx Comfort Club

Most RTU failures are preventable. Commercial rooftop units should be serviced at least twice a year, typically before the heating season and before the cooling season, to catch developing problems before peak demand arrives. Units that don’t receive consistent care commonly experience accelerated efficiency loss after the first decade, driving up operating costs and raising the risk of unplanned downtime when you can least afford it.

A proactive maintenance visit covers the components that determine reliability: filter replacements, coil cleaning, refrigerant charge checks, economizer function testing, electrical diagnostics, belt inspection, and performance tuning. That consistency can extend unit service life, reduce emergency repair frequency, and support Ontario building code compliance documentation.

The Marx Comfort Club is designed for commercial clients who want that consistency without managing it themselves. Members receive priority service scheduling, discounted repairs, and regular maintenance visits built into their plan. When something urgent comes up between scheduled visits, same-day availability and 24/7 emergency response mean the issue can be addressed fast.

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Make Marx Your First Choice Read Some of Our Five Star Reviews

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"Super work!"
Marx Mechanical Heating and Cooling did a wonderful job in repairing our ductless heat pump system. I highly recommend the company.

Leland D.
"Excellent HVAC company to work with!"
They took time to work with us to get the best furnace/heat pump to replace our 20-year-old furnace. They've checked in with us regularly, and while we haven't had any issues, we know that they would go above and beyond to fix anything!

Val R.
"Every step was smooth and competently handled."
We contracted Marx to replace our aging oil furnace with a high-efficiency heat pump. They arrived, promptly and prepared, on the agreed-upon installation date, protected walls and floors, worked diligently, and cleaned up afterward. Very professional!

Jabette B.
"I would highly recommend Marx Mechanical!"
Marx Mechanical replaced our old furnace with a new heat pump which has kept our house warm all winter. They worked with us to find the perfect system for our home and our unique needs.

Serena E.
"Exceptional service!"
Their team displayed extensive knowledge, answering all my questions thoroughly. The installation process was smooth and efficient, with a focus on precision and quality. The customer service was outstanding! They exceeded my expectations.

Adam H.
"Bravo!"
The Marx Team came to our rescue when our furnace was on the fritz and installed a new one with exceptional installation standards and had us up and running in no time! They are without a doubt the "Go To" HVAC company in the Durham-York Region!

Brian B.
"So pleased to have chosen Marx Mechanical!"
From the initial phone call, to the visit to the showroom, to the install, to the subsequent follow up of such, all the staff (including owner) could not have been more accommodating and more knowledgeable.

Karen H.
"Great team, great products, great experience."
The systems are exceptional. I wouldn't change a thing about the experience and I would highly recommend Jason and his team at Marx Mechanical for any such work. Solid pros, excellent experience from start to finish!

Daniel B.

Get a Free RTU Estimate from Your Uxbridge HVAC Team

Whether you need a rooftop unit repaired, replaced, or assessed for the first time, Marx Mechanical Heating and Cooling is ready to help. We provide free estimates on all RTU repair and installation projects, with same-day appointments available and 24/7 emergency coverage when the situation can’t wait. Financing through Financeit is available for qualifying installations and replacements.

We serve commercial clients throughout Uxbridge and the Greater Durham and York Regions. Call us at (289) 301-0414 or reach out through our online contact form to schedule your assessment.

What Makes Us Different? Benefits of Working with Our Expert Team

Local Values - Exceptional Service
Being family-owned and operated means more than just business to us—it’s about building lasting relationships. We’re proud to serve our community with care, integrity, and quality you can trust.
Year-Round Comfort With Our Memberships
Our membership plans are designed to keep your systems running smoothly all year long. Enjoy exclusive perks like priority service, discounted repairs, and regular maintenance.
Team of Highly Experienced HVAC Technicians

With decades of industry experience, Marx Mechanical Heating and Cooling delivers expert HVAC solutions with precision, reliability, and quality service.
Transparent, Upfront Pricing

We are committed to honesty and transparency in all our services. We offer upfront pricing with no hidden fees - just clear, fair quotes from an HVAC company you can rely on.

Join the Marx Comfort Club
Year-round comfort is only a click away! Our membership plans offer priority service, discounted repairs, and more!

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