Need help diagnosing my furnace once it goes into 1 hour lockout -
Got up this morning, house cold and furnace off. Pulled thermostat and jumpered Rh to W, nothing. Went to furnace, jumpered Rh to W on circuit board, nothing, not even draft inducer starting up. Noticed the green "OK" LED on the circuit board was flashing, but didn't have sense enough to count how many times. Turned off power and pulled all thermostat wires. Turned on power and jumpered Rh to W, now furnace comes on normally and works. Turn off power, reconnect thermostat wires, jumper Rh to W and it works fine. Go upstairs and connect thermostat to base unit, furnace doesn't come on even though the thermostat is calling for heat. Back down to the basement, there's no 24v at terminal W. Turn off power, pull thermostat, check pins on back of thermostat and Rh has continuity to W. Not sure what's going on, so I put the thermostat back on the base and heat comes on, everything working fine.
After staring at furnace documentation, I think what happened is furnace went into 1 hour lockout mode for reasons not yet determined. The 1 hour lockout gets reset by power cycling, so that's why it worked after I turned off the power. I'm looking for help diagnosing the cause next time this happens. Obviously I'll count the LED blinks to see what the error code is, but if it's in lockout mode, what do I do for further diagnostics? I'm confused about thermostat issue, it's relatively new, seems to work fine, not sure why it had that glitch. My technical skill level is pretty high but never worked on furnaces before.