Central heat and air installers typically minimise or avoid installing ventilation in bathrooms to prevent condensation build-up due to the extra moisture already present in the space. This can make for uncomfortable room temperatures. Air conditioning is typically not a major problem, but winter temperatures may make your bathroom nearly unusable, not to mention the increased risk of frozen pipes. Installing a forced air radiant heater is one way to alleviate this problem.
Turn off the breaker to the bathroom. Remove the cover from the vent fan. Typically these are fastened with a single thumbscrew in the centre. Twist it counterclockwise to remove it. Remove the bulb from the light. Locate the mounting screws and remove them with your cordless drill.
Pull the fixture down from the ceiling and twist off the wire nuts holding the wires together. Twist them counterclockwise to remove.
Match up the wire leads from the back of the heater unit with the cable in the junction box above. Match black to black, white to white and green to green. Use a wire nut to fasten each pair of wires together. Twist the wire nut clockwise to fasten.
Tuck the wires into the junction box and push the heater into the opening. Fit the new fixture to the face of the junction box. Install the mounting screws that came with your new fixture into the threaded holes in the junction box.
Install a light bulb into the light socket of the unit. Install the glass cover and screen or over the heater, if installation is required. Follow the installation instructions that came with your heater for specifics.