Under Ontario's Technical Standards and Safety Act and O. Reg. 220/01, boilers above certain capacity thresholds must be registered with the TSSA, inspected by a TSSA-authorized inspection body at specified intervals, and have current inspection certificates accessible. All gas appliance service must be performed by TSSA-registered contractors.

Commercial boilers should receive comprehensive annual service by a TSSA-registered contractor before the heating season — ideally completed by mid-October. Monthly operational checks by building staff are also recommended between professional service visits.

An annual service includes combustion analysis and burner adjustment, heat exchanger inspection, flue and venting inspection, gas pressure verification, ignition system test, safety control testing (high limit, low water cutoff, pressure relief valve), expansion tank check, pump seal inspection, water chemistry test, and a written service report.

Required safety controls include a temperature and pressure relief valve, a high limit control, a low water cutoff (steam boilers), a pressure relief device, and automatic gas shutoff interlocked with safety controls. These must be tested annually by a licensed technician.

Consider replacement when: the boiler is over 20 years old, heat exchanger failure is confirmed, repeated expensive repairs occur, TSSA compliance cannot be maintained economically, or the efficiency gap versus modern equipment makes replacement economically sound. A licensed contractor can provide a condition assessment.

A low water cutoff monitors water level (steam boilers) or pressure (hot water boilers) and shuts off the burner if the water drops below a safe minimum. Operating without water can cause catastrophic overheating. These must be tested annually.

No. Operating a boiler above the registration thresholds without a current TSSA inspection certificate violates the Technical Standards and Safety Act. The TSSA can order the boiler shut down. Insurance coverage may also be voided for incidents when required inspections were not maintained.

Common causes include leaks in the piping, a failed expansion tank causing the relief valve to weep repeatedly, improper makeup water system, and air in the system. Pressure loss should never be addressed by simply adding water — the root cause must be identified and corrected by a licensed contractor.