The thermostat has been changed. However, when the heater is turn on or work on automatic, and the heater will not blow hot air when thermostat is in the on position. This is for a mobile home is a1997 and the unit is a Coleman evcon unit .

The "on" setting on a thermostat usually is for the fan only. For heat, the stat should be set in the "heat" mode with the fan switch in the "auto" position.