No furnace ops

My barn furnace is "dead". It has a solid red LED. Fuse is OK; I have 24V from R to chassis gnd; I can work the cover switch off/on & see the voltage go to 27V actually & toggle to 0 when the cover is removed; no flue obstructions; plenty of LP; ??

The fan will not turn on either.

I am out of idea's now... Any help is appreciated.

Thanks !

(A) With the thermostat turned way up, do you have 24V at the "W" terminal to Chassis Ground...??
(ALT: You could also disconnect the red & white thermostat wires from board and run a jumper wire from R to W also.)
(B) Does the ventor motor come on...??

Please advise before going onto the next step(s).

My natural gas furnace has a condensation sump with a float activated pump and a float activated override which shuts down the fan and furnace if the pump fails to work. That is the condition it is in now. The switch on the float activated pump is bad, so when combustion produces enough condensation to fill the sump (about three pints) the float activated override switch shuts my system down so that the condensation water won't overflow and run onto the floor. I can run my furnace for about 4 hours before everything shuts down and I have to syphon the water out of the sump to get it going again. Your problem could be that.

All the best, Stan