We have a Maple Chase 9520 Thermostat. The thermostat suddenly lost it's display; and, the Heat Pump hooked to it is not working. We have checked the fuse and it looks OK. We are still going to try to find a fuse to fix it. Also, the breaker for the heat pump was fine and we are checking the fuses for the heat pump.

Any other thoughts? And, is there such a thing as a reset button?

Check to see if there is a fuse on the circuit board. Check the transformer for 24 volt output. If the stat has batteries replace them with known good ones.