Topic: Troubleshooting / GFCI Shuts off System

I have a Honeywell 7-day thermostat, model HWF1GA-15-120. The radiant coils were installed under ceramic tile two weeks ago and functioned well until yesterday. The GFI tripped and I have not been able to reset. The thermostat is on a dedicated 20 amp breaker not GFI protected. The ohms readings are within range so I am confident there isn’t a short in the floor coils. Please advise.