Hi - stumped by a thermostat or furnace problem

[mike_001]

I have a York G2FD series furnace run by Lux PSP511 thermostat. A couple of weeks ago the heating stopped working. I hit the reset button on the thermostat and that worked.

The same thing happened twice more - every time, the furnace worked fine then failed to turn back on after a period of low temp settings. Now however the reset does not work anymore.

I replaced the batteries on the thermostat, took the cover off - all wires seem clean and solidly attached.

I'd really appreciate any suggestions.

Thanks, mike

[HayZee518]

I went to the lux site and copied something in the specs:
NOT COMPATIBLE WITH:
Multi-stage Heat Pumps
Multi-stage Gas or Oil Furnaces
3 Wire Hydronic Systems
Is your system any of the above?

[hvacwiz]

Take the cover of the t-stat back off, put a jumper between r-w if your furnace runs you more than likely need a new stat.

[mike_001]

I did it and you were right. bought a new thermostat and everything's fine!

Much thanks, hvacwiz!

mike

[hvacwiz]

Your welcome.