Why does my heater have a ground wire but the thermostat has no terminal for ground?
Connect the protective ground wire leading from the unheated lead to the ground leading from the power supply.
Connect the Warmup heating mats to the electrical system through a Ground Fault Circuit Interrupter (“GFCI”). Otherwise, If you aren’t using a thermostat with a built-in GFCI, supply your system using dedicated GFCI protected circuits. This requirement is critical to the safe operation of your Warmup heating mat.
Additionally, all electrical work must be performed by a qualified electrician in accordance with local building & electrical codes and The Canadian Electrical Code.
Visit the installation and wiring manuals for further information.