# Commercial Furnace Repair Toronto | Toronto Commercial HVAC > Commercial furnace repair in Toronto for RTU gas heat, suspended unit heaters and industrial warm-air. $185 diagnostic, $450-$3,500. TSSA G1 and Enbridge-authorized. URL: https://torontocommercialhvac.ca/commercial-furnace-repair/ Repair $185+ diag # Commercial Furnace Repair in Toronto, ON | Rooftop Gas Furnace Sections, Unit Heaters & Industrial Warm-Air Last updated: October 10, 2026 Commercial furnace repair for rooftop unit gas heat sections, suspended unit heaters and industrial warm-air furnaces. Most failures are ignition, heat exchanger and drafting faults, and our TSSA G1 and Enbridge-authorized technicians handle shutdown, tagging and repair. Repair for RTU gas heat sections, suspended unit heaters and industrial warm-air. $450-$3,500. - Combustion and CO testing - Heat exchanger inspection - Ignition and inducer repair - 90-day labour warranty Call (437) 524-2997 [tel:+14375242997 →](tel:+14375242997) Request Service [/contact/ →](/contact/) View pricing [#pricing →](#pricing) ![Technicians inspecting a rooftop unit gas heat section in winter](/images/misc/two-technicians-inspecting-the-gas-heat-section-of.webp) Quick Facts Pricing $185+ diag Emergency response 2-4 hours, 24/7 Labour warranty 90 days Program lead Daniel Okonkwo, Operations Lead Commercial Credentials & Verification TSSA G1 + G2 Licensed Gas Technicians ESA Electrical Safety Authority 313A Refrigeration Licensed Refrigeration Mechanics $5M CGL + WSIB Enbridge-Authorized Since 2006 2-4 Hour Emergency Response 90-Day Labour Warranty on Repairs / 2-Year on Installs 5-Star Commercial Satisfaction 20+ Years Commercial-Only Toronto Commercial HVAC [/ →](/) repairs commercial furnaces across Toronto and the GTA: gas heat sections in packaged rooftop units, suspended gas unit heaters in warehouses and garages, and industrial warm-air furnaces serving plant floors. Our technicians are TSSA G1 licensed and Enbridge-authorized, so we can shut down, tag, repair and clear unsafe appliances. Most commercial furnace failures fall into three groups. Ignition faults: cracked hot surface igniters, dirty or weak flame sensors and failed ignition boards. Draft faults: failed inducer motors, blocked or damaged vent connectors and stuck pressure switches. Heat exchanger faults: cracks from years of thermal stress and low airflow, which can leak carbon monoxide into the building. The first two are usually quick fixes. The third is a safety shutdown. Furnace repairs typically run $450 to $3,500, plus a $185 diagnostic waived on repairs over $750. Every repair ends with a combustion and CO test. ## What Does Commercial Furnace Repair Cover? ### Rooftop unit gas heat sections The gas heat section of a packaged RTU is the most common commercial furnace in Toronto. We repair igniters, sensors, inducers, gas valves, limit switches and heat exchangers. Cooling-side and full-unit work sits under rooftop unit repair [/rooftop-unit-repair/ →](/rooftop-unit-repair/) . ### Suspended unit heaters Reznor and Modine unit heaters hang in warehouses, loading docks, garages and shops. Venting damage and dirty burners are the usual faults. ### Industrial warm-air furnaces Larger furnaces serving plant floors and shops, often with ducted distribution and higher firing rates. ## Furnace Failure Modes and Fixes | Fault | Signs | Typical fix | | --- | --- | --- | | Cracked igniter | Unit tries to light, then locks out | Igniter replacement | | Weak flame sensor | Lights for a few seconds, shuts off | Clean or replace sensor | | Inducer failure | Noise, pressure switch fault, no ignition | Inducer motor replacement | | Blocked or damaged vent | Pressure switch trips, rollout | Vent repair or replacement | | Cracked heat exchanger | CO readings, visible cracks, flame disturbance | Shutdown, heat exchanger or unit replacement | | Limit trips | Overheating from low airflow | Filters, blower, belts | ## When Should You Call for Furnace Repair? - Heat is locking out or cycling on and off. - You smell exhaust or see soot around the appliance. - A CO alarm sounds. Evacuate first, then call. - The utility or an inspector has red-tagged the unit. - Unit heaters in a warehouse light only after several tries. ## Repair or Replace a Commercial Furnace? Ignition and draft repairs are almost always worth doing. A cracked heat exchanger on a unit past 18 years, or one where parts are discontinued, usually points to replacement. We quote both in writing, and replacement work falls under commercial HVAC replacement [/commercial-hvac-replacement/ →](/commercial-hvac-replacement/) . ## Furnace Repair Across Toronto and the GTA We work in Scarborough Junction and Dufferin-Finch industrial buildings, Hwy 410 and Steeles warehouses, Dixon-Rexdale plants and retail plazas across the GTA. For boilers and radiant heat, see commercial heating repair [/commercial-heating-repair/ →](/commercial-heating-repair/) . Transparent Pricing ## How Much Does Commercial Furnace Repair Cost in Toronto? Diagnostic $185 Ignition, venting, combustion and heat exchanger inspection. - CO and combustion test - Camera inspection where needed - Written findings Book This [tel:+14375242997 →](tel:+14375242997) Most Requested Ignition and Draft $450-$1,400 Igniters, flame sensors, inducers, pressure switches, ignition boards. - Usually same visit - Draft verified - 90-day labour warranty Book This [tel:+14375242997 →](tel:+14375242997) Heat Exchanger $1,800-$3,500 Heat exchanger replacement where parts are available. - Unsafe units tagged out - Combustion commissioning - Replacement option quoted Book This [tel:+14375242997 →](tel:+14375242997) The $185 diagnostic is waived on repairs over $750. Heat exchanger replacements depend on part availability; when parts are no longer made, we quote unit replacement instead. Why Us ## Why Choose Toronto Commercial HVAC for Furnace Repair? ### Safety First Every furnace call includes a CO test. Cracked heat exchangers are shut down and tagged, never left running. ### TSSA G1 and Enbridge-Authorized Licensed for large gas equipment and authorized to repair and clear red-tagged appliances. ### Camera Inspections Borescope cameras confirm heat exchanger cracks so you are not replacing parts on a guess. ### Ignition Parts on Hand Igniters, flame sensors, inducers and pressure switches for common RTU and unit heater models. ### Insurer-Ready Records Combustion printouts and written findings for every appliance we touch. ### 90-Day Labour Warranty Furnace repairs carry a 90-day labour warranty, with manufacturer parts warranties passed through. ## Repair or replace? Get the numbers first. A $185 diagnostic gives you written findings per unit, waived when the approved repair is over $750. (437) 524-2997 [tel:+14375242997 →](tel:+14375242997) Request Service [/contact/ →](/contact/) Process ## How Does Our Furnace Repair Process Work? 1. 01 ### Call Dispatch No-heat and lockout calls get a 2-4 hour emergency response, 24 hours a day. 2. 02 ### Inspect Ignition sequence, draft, venting, gas pressure and heat exchanger checked, with a camera when cracks are suspected. 3. 03 ### Make Safe and Quote Unsafe appliances are shut down and tagged. You get written findings and a repair or replace quote. 4. 04 ### Repair Ignition and draft repairs usually close on the first visit. Daniel Okonkwo, Operations Lead, signs off every gas repair report. 5. 05 ### Test and Record Combustion and CO tests after repair, with printed results for your building file and insurer. Field Photos ## Furnace Repair Work on Toronto Commercial Sites Track Record ## Related Commercial Projects All projects [/projects/ →](/projects/) ![Gas technicians repairing a suspended unit heater in a Scarborough warehouse](/images/featured/two-gas-technicians-on-a-scissor-lift-repairing-a-.webp) [/projects/scarborough-warehouse-red-tag-clearance/ →](/projects/scarborough-warehouse-red-tag-clearance/) Scarborough $42,500 ### Scarborough Warehouse 7-Unit Enbridge Red Tag Clearance [/projects/scarborough-warehouse-red-tag-clearance/ →](/projects/scarborough-warehouse-red-tag-clearance/) Seven red-tagged gas appliances repaired, combustion tested and cleared in nine working days, so the warehouse had heat back before the first hard frost. Repair Case study [/projects/scarborough-warehouse-red-tag-clearance/ →](/projects/scarborough-warehouse-red-tag-clearance/) Client Feedback ## What Clients Say About Our Furnace Repair 5-Star Commercial Satisfaction > "Eight heaters were locking out every morning. They found damaged vents and two failed inducers and documented every unit for our insurer." Carla Mendes Facilities Manager, Furniture distribution warehouse Vaughan Venting and inducer repairs on 8 suspended unit heaters$7,200 > "Our shop floor furnace failed during a -18C week. They had it running the same afternoon and came back to tune combustion the next day." Bogdan Petrescu Plant Engineer, Metal fabrication plant Brampton Industrial warm-air furnace burner and ignition board repair$2,950 > "They caught two cracked heat exchangers during a routine call, shut the units down safely and had both replaced before the tenants noticed." Shawn Delaney Property Manager, Strip plaza with 9 tenants Scarborough RTU heat exchanger inspection and replacement on 2 units$6,400 Straight Answers ## Furnace Repair FAQs ### How much does commercial furnace repair cost in Toronto? + Commercial furnace repair in Toronto usually costs $450 to $3,500 plus a $185 diagnostic, which is waived on repairs over $750. Ignition and draft repairs such as hot surface igniters, flame sensors, inducer motors, pressure switches and ignition boards typically fall between $450 and $1,400 and are often finished on the first visit. Heat exchanger replacements, where parts are still available, run about $1,800 to $3,500. If the heat exchanger is no longer made or the unit is past 18-22 years, we quote replacement alongside the repair so you can compare. Every repair includes a combustion and CO test. ### What counts as a commercial furnace? + In commercial buildings, the furnace is usually the gas heat section inside a packaged rooftop unit, a suspended gas unit heater in a warehouse or garage, or an industrial warm-air furnace serving a plant floor. These run larger and longer than residential furnaces and need G1 or G2 licensed technicians. ### Why does my unit heater light and then shut off? + Usually a weak flame sensor signal, a blocked vent or a failed pressure switch. Venting problems are common in older warehouses where vent connectors have corroded or been damaged by forklifts. We test draft and flame signal to find the cause. ### How dangerous is a cracked heat exchanger? + A cracked heat exchanger can leak combustion gases, including carbon monoxide, into the supply air. We shut the appliance down, tag it and quote replacement of the heat exchanger or the unit. It is never safe to keep running. ### Do you handle Red Tag repairs on furnaces and unit heaters? + Yes. We are Enbridge-authorized and repair red-tagged appliances, then coordinate clearance. Our Scarborough warehouse project cleared seven red-tagged appliances in nine working days. ### How fast can you respond to a no-heat call? + No-heat emergencies get a 2-4 hour response across Toronto and the GTA, 24 hours a day. ### What standard do you follow for gas work? + CSA B149.1, the natural gas and propane installation code, along with TSSA requirements and manufacturer instructions. ### Can you repair old furnaces with discontinued parts? + Sometimes, using universal ignition parts. For discontinued heat exchangers, replacement of the unit is usually the safer and cheaper long-term option. ### Is there a warranty on furnace repairs? + Yes, a 90-day labour warranty, with manufacturer parts warranties passed through. ### Do you service furnaces as part of a maintenance plan? + Yes. Fall start-ups include combustion analysis, heat exchanger inspection and ignition checks on every gas heat section. Keep Exploring ## Related Services ![Gas technicians repairing a radiant tube heater inside a Toronto warehouse](/images/misc/two-gas-technicians-in-hard-hats-repairing-an-infr.webp) [/commercial-heating-repair/ →](/commercial-heating-repair/) ### Commercial Heating Repair [/commercial-heating-repair/ →](/commercial-heating-repair/) $185+ diag Heating repair for boilers, radiant heaters, RTU heat sections and MUA. $450-$4,500. View service [/commercial-heating-repair/ →](/commercial-heating-repair/) ![Technicians in fall-arrest harnesses repairing a rooftop unit on a Toronto plaza roof](/images/misc/two-technicians-in-hard-hats-and-fall-arrest-harne.webp) [/rooftop-unit-repair/ →](/rooftop-unit-repair/) ### Rooftop Unit Repair [/rooftop-unit-repair/ →](/rooftop-unit-repair/) $185+ diag RTU repair for all major manufacturers, 3 to 150 tons. $450-$5,500. View service [/rooftop-unit-repair/ →](/rooftop-unit-repair/) ![Gas technicians repairing a condensing boiler in a Toronto commercial boiler room](/images/misc/two-tssa-gas-technicians-repairing-a-lochinvar-cre.webp) [/commercial-boiler-repair/ →](/commercial-boiler-repair/) ### Commercial Boiler Repair [/commercial-boiler-repair/ →](/commercial-boiler-repair/) $185+ diag Hydronic, steam, condensing and firetube boiler repair, 500-6,000 MBH. $650-$8,500. View service [/commercial-boiler-repair/ →](/commercial-boiler-repair/) ![Emergency technicians working on a rooftop unit at night in Toronto](/images/misc/two-emergency-hvac-technicians-with-headlamps-work.webp) [/emergency-commercial-hvac-repair/ →](/emergency-commercial-hvac-repair/) ### 24-Hour Emergency Commercial HVAC Repair [/emergency-commercial-hvac-repair/ →](/emergency-commercial-hvac-repair/) $185 surcharge 24-hour emergency dispatch across Toronto and the GTA with 2-4 hour response. View service [/emergency-commercial-hvac-repair/ →](/emergency-commercial-hvac-repair/) ![](/images/misc/two-commercial-hvac-technicians-in-hard-hats-walki.webp) 24-Hour Commercial Emergency Dispatch ## Ready to Book Furnace Repair? Commercial Furnace Repair across Toronto and the GTA: $185+ diag, written findings before any work, and a 2-4 hour emergency response. Call (437) 524-2997 [tel:+14375242997 →](tel:+14375242997) Request Service [/contact/ →](/contact/) - TSSA G1+G2, ESA, 313A - Written findings every visit - 90-day / 2-year labour warranty