The Reset indicator button on the right side of my Hilo smart thermostat for electric floor heating is lit (red). What should I do?

When the Reset indicator button is illuminated, this means that the ground fault protection circuit has been tripped. You can try to reset the ground fault circuit by pressing the Reset button.

If this does not resolve the issue, cut the power to the circuit in the electrical panel and have your wiring checked by an electrician.