Electric In-Floor Heating System Installations

Ontario’s Electrical Safety Authority (ESA) warns the public that improperly installed
electric floor heating systems may pose a fire, burn, or electric shock hazard. A recent
fatality has been associated with floor heating cables/ pads that were not installed as
per the manufacturer and were not in compliance with the Ontario Electrical Safety
Code (OESC).
Caution for Home Owners:
Homeowners are reminded to review and always follow the manufactures operating
instructions. Objects that significantly restrict the normal flow of air over a floor should
not be left unattended on floors heated with Electric In-Floor Heating Systems, unless
specifically permitted by the manufacturer’s instructions.
Caution for Installers:
Recently, an elderly gentleman fell on the floor in the bathroom of his home where a
Licensed Electrical Contractor (LEC) had installed an in-floor heating system without
taking out a notification of work. The man suffered second and third degree burns from
the over-heated floor and succumbed to his injuries weeks later in hospital.
A joint investigation with the ESA revealed the sensor (heat) that needed to be installed
to cut the electrical supply to the floor when a certain temperature is reached was not
installed. Also, the In-Floor Heating mat was intended to be connected to 120 VAC
power supply. It was hooked up to a 240 VAC power supply by mistake, allowing it to
overheat. The floor was able to attain a temperature of 62.2 °C (144 ° F).
Installers should be aware most thermostats are rated for multiple voltages. The
thermostat does not reduce the voltage so extreme caution should be taken to ensure
the voltage supplied to the thermostat matches the voltage required by the in-floor
heating mat or cable installed.