I have a baseboard heater with a 24 volt transformer to the thermostat. I replaced a mercury thermostat following the wiring diagram for single stage with single transformer in the 1F80-0471 manual. When it calls for heat the display flashes and clicks every 2-3 seconds. I left the jumper between RH and RC, connected the whit wire to RH, the black toC and jumpered C to W. What have I done wrong?