I installed a 120v floor warming system for tile floor. Th cost of the thermostat exceed cost of wire, so in my wisdom, I opted to not use thermostat control from manufacturer but rather use standard double pole dimplex thermostat for electric heaters. Not sure if this was good choice, so here are my questions. Can I use this? I have a red, black and ground coming from the box (12-2) The thermostat has 2 red and 2 black. The tile floor warmer has one black, one white and a ground. If I can use this configuration safetly on a 15 amp dedicated breaker (Resistance of floor warmer is 7 amps), how do I wire it?

I understand that I will not have thermostatic control of the floor. I was looking for a manual adjustment.

Thanks