# Commercial Rooftop Unit Repair Toronto | 24/7 Dispatch > Need commercial rooftop unit repair in Toronto? TSSA G1/G2 crew, 24/7 dispatch, 2-hour response, diagnostics from $500. Call 647-254-4113. URL: https://besthvactoronto.ca/commercial-rtu-repair-toronto/ ![Best HVAC Toronto TSSA-certified technicians diagnosing a commercial rooftop unit on a flat Toronto retail plaza roof](/images/hero/tssa-certified-technicians-diagnosing-a-commercial.webp) # Commercial Rooftop Unit Repair for Toronto Properties Last updated: October 26, 2026 Best HVAC Toronto [/ →](/) has over 20+ years of Greater Toronto Area experience specialising in commercial rooftop unit (rtu) repair toronto across Toronto and the wider GTA. Commercial rooftop unit repair and RTU diagnostics for Toronto, Mississauga, and GTA property managers, facility operators, and business owners. Our TSSA-certified crew services Carrier WeatherMaker, Trane Voyager, Lennox Landmark, York Sunline, Bosch, and Daikin commercial packaged RTUs with rapid dispatch and same-visit component repair. Symptom-by-symptom diagnostic covers compressor lockouts, ignition faults, tripped breakers, cooling loss, economizer damper failures, refrigerant leaks, and control board faults, with combustion analyzer readings on gas heating sections and superheat and subcool refrigerant checks on cooling circuits. Emergency dispatch runs 24/7 with a target 2-hour on-site response window across Toronto and the GTA, and every repair is quoted in writing before work begins. Property manager audience: Certificate of Insurance (COI) provided on request, master key protocols standard, background-checked technicians, and additional insured endorsements available for tenant agreements. Common failure parts stocked on every van so most emergency repairs are completed same-visit. All repairs quoted in writing before work begins. Emergency dispatch available 24/7. Same-day weekday capacity. 24/7 dispatch for gas emergencies and Enbridge Red Tags. - check\_circle TSSA G1/G2 certified - check\_circle 20+ years experience - check\_circle Manufacturer-Authorized Dealer call Call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) View pricing [#pricing →](#pricing) payments **From $500**. diagnostic to compressor replacement, depending on fault - star star star star star 4.9 (150+ reviews) - verified TSSA G1/G2 Certified & $2M Insured - bolt 2-Hour Emergency Response - workspace\_premium Manufacturer-Authorized Dealer Common problems ## Sound familiar? business ### A rooftop unit down during business hours Lost heating or cooling in a restaurant, retail unit, or office costs revenue by the hour. We dispatch within 2 hours, 24/7, to get your RTU back online. warning ### Repeated callouts with no lasting fix A compressor lockout or tripped breaker that keeps returning is a symptom of a deeper fault. We diagnose the root cause rather than clearing codes and leaving. request\_quote ### No documentation for property manager reporting We provide written diagnostic reports, COI, and WSIB documentation with every service call so property managers have the records they need without chasing anyone. ## What does a commercial RTU repair call cover? Best HVAC Toronto is a TSSA-certified commercial and residential HVAC contractor providing commercial rooftop unit repair for property managers, restaurants, retailers, and office operators across Toronto and the GTA, backed by a 2-hour emergency response target and over 20 years of combined crew experience. A packaged RTU combines gas heating, mechanical cooling, and fresh-air ventilation in a single cabinet mounted on a roof curb, and on most low-rise commercial buildings it is the core of the commercial HVAC system [/commercial-hvac/ →](/commercial-hvac/) . When one fails, it can knock out all three functions simultaneously, and for a commercial operator, every hour without conditioned air has a measurable cost. Commercial rooftop unit repair in Toronto runs from $500 for an on-site diagnostic to $20,000 for a compressor replacement. Our TSSA-certified crew dispatches within 2 hours, 24/7, to commercial sites across the GTA, and most common single-component failures are resolved on the same visit. Call 647-254-4113 to reach our commercial dispatch at any hour. ![Technician performing symptom-based RTU diagnosis on a Lennox Landmark rooftop unit at an Etobicoke strip plaza in Toronto](/images/content/technician-performing-symptom-based-rtu-diagnosis-.webp) Best HVAC Toronto’s crew holds TSSA G1 and G2 gas licences, which means the gas heating section of your RTU is handled in-house. A gas fault on a commercial rooftop unit can draw an Enbridge red tag under the same CSA B149.1 gas code rules as any residential appliance, and having G1/G2 certified technicians on the same crew that diagnoses the refrigerant circuit means the unit is cleared and back online without waiting on a second contractor. We carry COI and WSIB documentation to every commercial site so property managers can retain current vendor records without chasing documents after the job. ### What our crew carries on the van As a manufacturer-authorized dealer for Lennox, Carrier, Trane, Bosch, Napoleon, and York, our vans carry common replacement parts for Carrier WeatherMaker, Trane Voyager, Lennox Landmark, and York Sunline units: run capacitors, contactors, hot surface igniters, flame sensors, economizer actuators, and refrigerant for common circuit sizes. That parts inventory is why most single-component failures are resolved in one visit rather than two. ## Why does your RTU keep failing, and how do we find the real cause? Property managers and facility operators describing an RTU problem are almost always describing a symptom rather than a cause, whether the unit sits on a Scarborough strip plaza, a King West restaurant, or a North York low-rise office building. Here is how our crew works through the five most common failure modes. ### Compressor lockout A compressor lockout is a safety shutdown that fires when the unit detects an out-of-range condition: low or high refrigerant pressure, an excessive discharge temperature, a voltage fault at the incoming power, or a motor current overload. Clearing the fault code without identifying the underlying condition means the unit will lock out again within hours. Our crew measures refrigerant suction and discharge pressures, checks incoming voltage and phase balance, tests the run capacitor and start components, and inspects the compressor for mechanical signs of distress before recommending a repair path. A refrigerant undercharge, a failing run capacitor, and an intermittent contactor are the three most common causes found on Toronto commercial sites. ### Ignition fault on the gas heating section An ignition fault means the gas heating section failed to light or failed to prove a flame after lighting. Common causes include a cracked or degraded hot surface igniter, a dirty or out-of-position flame sensor, a faulty induced draft motor, or a gas pressure fault at the valve. Our G1/G2 certified technicians diagnose and repair gas heating sections in-house. For a commercial operator with no heat on a cold day, that shortens the outage from days to hours. ### Tripped circuit breaker A tripped breaker on a commercial RTU is usually caused by a compressor drawing excess current during a hard start, a failed run capacitor causing locked-rotor current, a short in a condenser or evaporator fan motor winding, or a ground fault in the controls wiring. Resetting the breaker without a load test risks a second trip and potential equipment damage. We test the circuit under operating conditions, measure individual motor currents, and check insulation resistance before recommending a repair. ### Cooling loss Cooling loss is the most common reason tenants call for commercial air conditioner repair in July and August, and it traces to one of four causes: a refrigerant leak that has reduced the charge below operating range, a failed or degraded compressor, a condenser coil restricted by debris or fouling that limits heat rejection, or a failed TXV or metering device. We measure suction and discharge pressures, superheat, and subcooling during every diagnostic to isolate the cause accurately rather than guessing. ### Economizer failure A rooftop economizer brings in outdoor air for free cooling when outside conditions are suitable, saving compressor runtime during Toronto’s shoulder seasons. Common failure modes include a seized or frozen damper motor, a failed enthalpy sensor, or a damaged actuator linkage. A damper stuck fully open wastes heating capacity in winter; fully closed means the unit runs the compressor when free cooling was available. Actuator and sensor replacements are typically same-visit repairs. ## Which Carrier, Trane, Lennox, and York rooftop units do you service? Our team services Carrier WeatherMaker, Trane Voyager, Lennox Landmark, and York Sunline packaged rooftop units and carries common replacement parts for each platform. These four brands account for the majority of commercial RTUs on Toronto retail plazas, restaurants, and low-rise office buildings, and we also service Bosch and Daikin commercial packaged units. For sites with other brands, call to confirm part availability before booking. ## How much does commercial rooftop unit repair cost in Toronto? In 2026, the diagnostic call is $500 and establishes the root cause. What varies after that is the repair scope. A capacitor, contactor, or igniter replacement is a same-visit job and typically runs $1,000 to $2,500 all in. An economizer actuator or sensor replacement sits in a similar range. A refrigerant leak repair and recharge adds the cost of refrigerant, which has increased as R-410A is phased out in favour of lower-GWP alternatives such as R-454B. A compressor replacement is the largest cost: parts, refrigerant recovery and recharge, and labour on an access-restricted rooftop bring the total to $10,000 to $20,000 depending on unit size and refrigerant type. On a unit older than 15 years with a failed compressor, RTU replacement is often the better long-term value, and our crew will give you both numbers in writing before you decide. When replacement wins, the same crew handles crane-lift RTU replacement [/commercial-rtu-crane-replacement-toronto/ →](/commercial-rtu-crane-replacement-toronto/) . Timing also affects the bill. Work scheduled outside operating hours, including evenings or weekends, carries a premium in labour but avoids lost revenue during the repair. For restaurants and retail units in particular, the premium is usually far less than the cost of a closed day. ## Serving property managers in Toronto, Mississauga, and the GTA We dispatch to commercial sites across Toronto, North York, Etobicoke, Scarborough, Mississauga, Brampton, Vaughan, Markham, Richmond Hill, and the broader Durham region including Ajax, Pickering, and Whitby, from Financial District office towers and Liberty Village restaurants to the industrial parks around Pearson Airport in Mississauga. If you are searching for rooftop unit repair near you anywhere in that area, the 2-hour target response is the same, 24 hours a day. Our office line is staffed Monday to Saturday, 7 AM to 8 PM, and commercial emergency dispatch covers every other hour. For property managers handling multi-site portfolios, our service documentation includes a written diagnostic report, all repair findings, and the full repair scope for your records. COI and WSIB certificates are available in advance of arrival for sites with vendor pre-qualification requirements. For commercial gas compliance [/enbridge-red-tag-compliance/ →](/enbridge-red-tag-compliance/) issues that accompany an RTU fault, our G1/G2 technicians handle the inspection, repair, and clearance on the same visit. Buildings that want fewer emergency calls can move to a commercial HVAC preventative maintenance [/commercial-hvac-preventative-maintenance-toronto/ →](/commercial-hvac-preventative-maintenance-toronto/) contract with biannual or quarterly RTU servicing. To reach Best HVAC Toronto’s 24/7 commercial RTU dispatch, call 647-254-4113. Transparent pricing ## How much does rtu repair cost in Toronto? All repairs quoted in writing before work begins. Emergency dispatch available 24/7. receipt\_long Written quote before any work begins. No hidden fees. ### RTU diagnostic call On-site fault diagnosis and written report Starting from $ 500 diagnostic to compressor replacement, depending on fault - check Full RTU inspection and fault isolation - check Refrigerant pressure and electrical checks - check Combustion analysis on gas heating sections - check Written findings for property manager records Get a quote [tel:+16472544113 →](tel:+16472544113) MOST COMMON ### Common component repair Typical single-component failure, same-visit Starting from $ 2,500 diagnostic to compressor replacement, depending on fault - check Everything in the diagnostic - check Capacitor, contactor, or igniter replacement - check Economizer damper and actuator repair - check Refrigerant top-up or minor leak repair Get a quote [tel:+16472544113 →](tel:+16472544113) ### Compressor replacement Major component or full refrigerant circuit Starting from $ 20,000 diagnostic to compressor replacement, depending on fault - check Full refrigerant recovery and recharge - check Compressor or condenser coil replacement - check Electrical and controls verification - check Manufacturer warranty on replacement parts Get a quote [tel:+16472544113 →](tel:+16472544113) Prices are guide ranges for Toronto and the GTA. Final pricing depends on your equipment, access, and site conditions, and we confirm it in writing before starting. Request a free estimate [/contact/ →](/contact/) or call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) . savings Financing available on approved credit, plus lease-to-own with zero down on qualifying installs. Why us ## Why choose Best HVAC Toronto for rtu repair? workspace\_premium ### TSSA G1/G2 certified for gas RTU sections Commercial RTUs with gas heating sections are regulated gas appliances. Our technicians hold the G1 and G2 licences required to inspect, repair, and clear them without bringing in a second contractor. bolt ### 2-hour response target, 24/7 We hold a 2-hour dispatch target across Toronto and the GTA for commercial RTU breakdowns, including evenings, weekends, and statutory holidays. verified\_user ### COI and WSIB on file Property managers and facility operators receive WSIB clearance certificates and a certificate of insurance with every service call, keeping vendor records current without chasing documents. domain ### Brand-specific RTU expertise Our crew services Carrier WeatherMaker, Trane Voyager, Lennox Landmark, and York Sunline units regularly and carries common replacement parts for each platform on the van. ## How Best HVAC Toronto compares | Feature | Typical provider | Best HVAC Toronto | | --- | --- | --- | | Emergency response | Next business day at earliest | 2-hour target, 24/7 including weekends | | Gas heating section work | Subcontracted to a separate gas contractor | TSSA G1/G2 in-house, no second contractor | | Documentation | Invoice only | Written diagnostic report, COI, WSIB certificate | | Parts availability | Ordered in, job delayed | Common Carrier, Trane, Lennox, York parts on van | | Quote before repair | Verbal or after the fact | Written fixed price in CAD before work begins | How it works ## How does our rtu repair service work? 1. 1call ### Call 24/7 dispatch Call 647-254-4113 and describe the symptoms: no cooling, no heating, tripped breaker, or active fault code. We dispatch within 2 hours to commercial sites across the GTA. 2. 2search ### On-site RTU diagnostic Our crew inspects the full unit: refrigerant pressures, electrical and controls, gas heating section, economizer, and any active fault codes. You receive written findings. 3. 3build ### Written quote, then repair You approve a fixed written price in CAD before we touch anything. Most common faults are resolved on the same visit because our vans carry parts for Carrier, Trane, Lennox, and York units. 4. 4verified ### Test and document Full verification after the repair: temperature rise, refrigerant charge, economizer operation, and controls. You receive a service report for property manager records. ## Not sure what your rtu repair situation needs? Get a straight answer and a written price, with the numbers to back it up. No pressure, no scare tactics. call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) Book Online [/contact/ →](/contact/) Our work ## Recent rtu repair projects Click any image to enlarge. Reviews ## What customers say about our rtu repair work starstarstarstarstar4.9 out of 5 from 150+ customer reviews star star star star star > They took over four buildings from a previous contractor and had the boiler rooms documented properly within a month. Reporting is far better than what we had. PProperty manager, mid-rise portfolioToronto star star star star star > Make-up air unit failed on a Friday. They were on the roof within a couple of hours and we opened on time. That response is why we signed a maintenance agreement. RRestaurant ownerMississauga star star star star star > Two rooftop units replaced over a weekend so we never lost a shift. Crane, permits, and the schedule were all handled without us chasing anyone. WWarehouse operations leadBrampton FAQ ## RTU Repair questions, answered ### How much does commercial RTU repair cost in Toronto? expand\_more A diagnostic call runs $500 and covers on-site fault isolation and a written report. Common single-component repairs, such as a capacitor, contactor, igniter, or economizer actuator replacement, typically total $1,000 to $2,500 all in (2026 pricing). A compressor replacement or major refrigerant circuit repair runs $10,000 to $20,000 depending on tonnage and refrigerant type. All work is quoted in writing in CAD before we begin. ### Which RTU brands does your crew service? expand\_more Best HVAC Toronto is a manufacturer-authorized dealer for Lennox, Carrier, Trane, Bosch, Napoleon, and York. Our crew regularly services Carrier WeatherMaker, Trane Voyager, Lennox Landmark, and York Sunline packaged rooftop units, and carries common replacement parts for each on the van. These four brands cover the majority of commercial RTUs across Toronto's retail, restaurant, and office stock. If your site has a different brand, call to confirm part availability. ### What does a compressor lockout mean on a commercial RTU? expand\_more A compressor lockout is a safety shutdown triggered when the unit detects an out-of-range condition: low or high refrigerant pressure, a high discharge temperature, a voltage fault, or a motor current overload. Clearing the fault code without addressing the root cause means the unit will lock out again within hours. Our crew diagnoses the triggering condition and repairs it rather than simply resetting the fault. ### What is an economizer fault and how is it repaired? expand\_more An economizer is a damper assembly that brings in outdoor air for free cooling when outside conditions allow, saving compressor runtime during Toronto's shoulder seasons. Common faults include a seized damper motor, a failed enthalpy sensor, or a damaged actuator. A damper stuck fully open wastes heating capacity in winter; fully closed means lost free cooling in summer. Actuator and sensor replacements are typically completed on the same visit. ### What causes an ignition fault on a gas RTU? expand\_more An ignition fault means the gas heating section failed to light or failed to prove a flame after lighting. Common causes include a cracked or degraded hot surface igniter, a dirty or out-of-position flame sensor, a faulty induced draft motor, or a gas pressure fault at the valve. Our TSSA G1/G2 certified technicians diagnose and repair gas heating sections in-house, which avoids the delay of coordinating a separate gas contractor. ### What causes a tripped breaker on a rooftop unit? expand\_more A tripped breaker on a commercial RTU is usually caused by a compressor drawing excess current on start, a failed run capacitor causing locked-rotor current, a short in a condenser or evaporator fan motor winding, or a ground fault in the controls wiring. Resetting the breaker without a load test risks a second trip and potential equipment damage. We test the circuit under operating conditions before recommending a repair. ### What causes cooling loss on a commercial rooftop unit? expand\_more Most summer commercial air conditioner repair calls on rooftop units trace to one of four causes: a refrigerant leak that has reduced the charge below operating range, a failed or degraded compressor, a condenser coil restricted by debris or fouling, or a failed TXV or metering device. We measure refrigerant pressures, superheat, and subcooling during every diagnostic to distinguish between these causes accurately. ### Do you provide COI and WSIB documentation for property managers? expand\_more Yes. We provide a current certificate of insurance and WSIB clearance certificate with every commercial service call. If your property management system requires these documents before a vendor can access the roof or mechanical room, our dispatch team can send them in advance of arrival. ### Can you respond to RTU breakdowns outside business hours? expand\_more Yes. Our commercial dispatch runs 24/7 with a 2-hour target response across the GTA, including evenings, weekends, and holidays. For sites where after-hours roof access requires coordination with building security or property management, let our dispatch team know when you call so we can arrange it ahead of arrival. ### Should I repair or replace a commercial rooftop unit? expand\_more Repair is the better value when a unit under 15 years old has a single failed component such as a capacitor, contactor, igniter, or economizer actuator. On a unit older than 15 years with a failed compressor, a $10,000 to $20,000 repair often approaches the cost of a new RTU, and replacement brings a lower-GWP refrigerant and better efficiency. We put both the repair price and the replacement price in writing so you can compare them before deciding. ### How often should commercial rooftop units be serviced in Toronto? expand\_more Commercial RTUs in Toronto should be serviced at least twice a year: a spring visit before cooling season for refrigerant charge, coils, and the economizer, and a fall visit before heating season for the gas heating section, igniter, flame sensor, and heat exchanger. Restaurants and sites with heavy grease or dust loads benefit from quarterly visits. A planned maintenance agreement adds documented readings at every visit, filter and belt replacement, and priority dispatch when a breakdown occurs. ## Related services apartmentCommercial HVACRTUs, restaurant and retail systems, warehouse HVAC, and planned maintenance agreements. [/commercial-hvac/ →](/commercial-hvac/) gpp\_maybeEnbridge Red Tag Emergency ComplianceSame-day red tag inspection, repair, and re-certification so Enbridge can turn your gas back on. [/enbridge-red-tag-compliance/ →](/enbridge-red-tag-compliance/) device\_thermostatBoiler Installation & RepairCombi, condensing, and hydronic boiler installation, repair, and annual maintenance. [/boiler-installation-repair/ →](/boiler-installation-repair/) ![](/images/hero/hvac-technician-in-plain-grey-uniform-kneeling-bes.webp) 24/7 for gas emergencies, red tags, no-heat and no-AC ## Ready to book rtu repair? Commercial rooftop unit repair and RTU diagnostics for Toronto, Mississauga, and GTA property managers, facility operators, and business owners. Our TSSA-certified crew services Carrier WeatherMaker, Trane Voyager, Lennox Landmark, York Sunline, Bosch, and Daikin commercial packaged RTUs with rapid dispatch and same-visit component repair. Symptom-by-symptom diagnostic covers compressor lockouts, ignition faults, tripped breakers, cooling loss, economizer damper failures, refrigerant leaks, and control board faults, with combustion analyzer readings on gas heating sections and superheat and subcool refrigerant checks on cooling circuits. Emergency dispatch runs 24/7 with a target 2-hour on-site response window across Toronto and the GTA, and every repair is quoted in writing before work begins. Property manager audience: Certificate of Insurance (COI) provided on request, master key protocols standard, background-checked technicians, and additional insured endorsements available for tenant agreements. Common failure parts stocked on every van so most emergency repairs are completed same-visit. Written quotes before work begins, and manufacturer parts coverage registered on your behalf. call Call 647-254-4113 [tel:+16472544113 →](tel:+16472544113) Get a Free Estimate [/contact/ →](/contact/) - check\_circle Manufacturer registration filed on your behalf - check\_circle Written quotes before work starts - check\_circle TSSA G1/G2 certified, WSIB covered Cities we serve ## Commercial RTU Repair Across the GTA Rooftop unit diagnostic and repair for Carrier WeatherMaker, Trane Voyager, Lennox Landmark, and York Sunline commercial packaged RTUs. Compressor lockouts, ignition faults, tripped breakers, and economizer damper failures with 2-hour target response for property managers and facility operators. ### Commercial RTU Repair in North York City of Toronto [Commercial RTU Repair in North York →](/commercial-rtu-repair-toronto/north-york/) ### Commercial RTU Repair in Etobicoke City of Toronto [Commercial RTU Repair in Etobicoke →](/commercial-rtu-repair-toronto/etobicoke/) ### Commercial RTU Repair in Scarborough City of Toronto [Commercial RTU Repair in Scarborough →](/commercial-rtu-repair-toronto/scarborough/) ### Commercial RTU Repair in Vaughan City of Vaughan [Commercial RTU Repair in Vaughan →](/commercial-rtu-repair-toronto/vaughan/) ### Commercial RTU Repair in Markham City of Markham [Commercial RTU Repair in Markham →](/commercial-rtu-repair-toronto/markham/) ### Commercial RTU Repair in Mississauga Peel Region [Commercial RTU Repair in Mississauga →](/commercial-rtu-repair-toronto/mississauga/) ### Commercial RTU Repair in Brampton Peel Region [Commercial RTU Repair in Brampton →](/commercial-rtu-repair-toronto/brampton/) ### Commercial RTU Repair in Richmond Hill City of Richmond Hill [Commercial RTU Repair in Richmond Hill →](/commercial-rtu-repair-toronto/richmond-hill/) ### Commercial RTU Repair in East York City of Toronto [Commercial RTU Repair in East York →](/commercial-rtu-repair-toronto/east-york/) ### Commercial RTU Repair in Oakville Halton Region [Commercial RTU Repair in Oakville →](/commercial-rtu-repair-toronto/oakville/) ### Commercial RTU Repair in Burlington Halton Region [Commercial RTU Repair in Burlington →](/commercial-rtu-repair-toronto/burlington/) ### Commercial RTU Repair in Ajax Town of Ajax [Commercial RTU Repair in Ajax →](/commercial-rtu-repair-toronto/ajax/)