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.
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.
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.
