Model 25 HBA The light on my thermostat went out and the fan keeps blowing. There seems to be two breakers for the furnace that I will be checking. What could be causing this malfunction.

Thanks... Kathy

The model # you gave is for the outside heat pump. The problem will be with the indoor blower section. Turn the breaker going to the blower section to off and then back on, to see if it was tripped. Loss of line voltage or 24v will give you a blank thermostat. Loss of 24v--- blown transformer or open low voltage fuse on control board.