I've never had any problems with this thermostat, but after a service man made some adjustments to the wiring in the furnace the fan is not functional. Does this mean that a new thermostat is needed? Also, I was told by the installation company that this WR 1F80-51 is no longer available, but the manufacturer recommends 1F80-382, which is not found under searches. Does any have comments or advise.