A bathroom heat lamp takes the edge off a cold morning without heating the whole room. Installing one is a straightforward electrical job — but there are specific code requirements in Ontario for bathroom circuits that every homeowner should know before starting.
Bathroom heat lamps use infrared bulbs — typically 250W or 375W — that emit radiant heat rather than convective heat. They warm objects and people directly rather than heating the air. Most residential bathroom heat fixtures combine one or two heat lamps with a fan and a standard light — a 3-in-1 or 4-in-1 unit that handles heating, ventilation, and lighting from one ceiling fixture.
A single 250W infrared bulb draws about 2.1A. A standard 2-bulb heat lamp draws about 4.2A, plus fan and light load. A 3-in-1 unit with two 250W bulbs, a fan, and a 100W light draws close to 5A total — well within a 15A circuit. However, the Ontario Electrical Code requires bathroom circuits to be GFCI-protected, and many code-compliant installations put the heat lamp on its own dedicated circuit, separate from the GFCI receptacle circuit.
If your heat lamp is a combined fan-heater unit over 1,500W, it typically requires a dedicated 20A circuit. Check the fixture’s nameplate amperage before choosing wire gauge and breaker size.
Turn off the bathroom circuit at the panel. The heat lamp mounts in the ceiling at a junction box — it replaces an existing fixture or goes in a new opening cut to size. Standard units mount to a 4-inch octagonal box. Connect the fixture wires to the supply: black to black (hot), white to white (neutral), bare copper to green (ground). Heat lamp fixtures with fans require a dedicated neutral wire at the switch location for each function — if you’re wiring a new installation, run a 3-conductor cable (NMD-90 14/3) from the fixture box to the switch location to give heat, fan, and light their own switching.
Installing a new heat lamp circuit in Ontario requires an ESA permit and inspection. The homeowner can do the work in their primary residence, but the permit is mandatory for a new circuit. The ESA inspection is typically quick: an inspector confirms the circuit is properly protected and the fixture is correctly mounted. Running the permit through the ESA’s online portal takes about 15 minutes.
The most common mistake on bathroom heat lamp installs is positioning the fixture too close to the shower or tub. The Ontario Electrical Code requires a minimum Zone 2 clearance — heat lamps are not rated for Zone 0 or Zone 1 placement (inside or immediately adjacent to the shower or tub). A reliable rule of thumb: position the fixture closer to the door or vanity than to the shower head. This keeps it in a compliant zone, provides effective warmth when stepping out, and prevents moisture from reaching the fixture’s electrical components over time.
Planning a bathroom heat lamp installation? Call us at 416-838-9006 or visit our contact page — we install bathroom heat lamps and ventilation fans across the GTA.
Electrician Since 2008 Journeyman Electrician Designated Master Electrician at EZSMART Corp