Gas and Oil Home Heating Furnaces - honeywell thermostat or miller furnace problem

i turned our gas heater on the other day and after some time it shut off but it hadnt heated the house up yet. i went to the thermostat and it seemed to be froze up no buttons would work and it read 74 degress. I went to work and when i came back it was now a blank screen the screen comes on only for the ac but the ac doesnt actually work. when i switch it to off or heat the display shuts right down to a blank screen. if i switch the thermostat to fan instead of auto it does kick the fan on....any help would be appriciated no heat and its getting cold.

never mind the a/c does work b ut still screen goes blank for heat and heater doesnt turn on

Hi J:

Does the thermostat have batteries? Maybe they need replacing?

Was this t-stat just added or had it for a while? LIke John said, how's the battery?

yes we had it for a while, no batteries...just a switch with F or E and a screw that says "do not unscrew"

Switch stays on F.

Sounds like the t-stat may be at the end of it's life.

before we rule out the t-stat. Undo the t-stat, and touch the R and W wires. The furnace should come on.. Leave the wire on for awhile to see if the furnace acts up or not.