Sorry for the Unsui move of no model number, I will get one asap, will go back in a little while. Tenants said that heat was intermittent. (Why I cant I get these calls during the week?) Furnace flashing code 14 - Ignition Lockout - Ignition will auto reset after 3 hours (refer 34) I open the unit and put back together, tripping the door switch I guess, she started to cycle again. LED steady. Everything seemed normal, little fan spinning, blower starts up, ignition coil turns read, flames look great.... and poof, everything shuts down. ( Want to say the blower stopped at some point and I wasnt sure if that was normal.) LED flashing code 34 - Ignition Proving Failure Control will try 3 times... 3rd time a charm. Lights up, fires up, blower running, heat good. Light steady when I left, but I know I need to do something. Service code 34 says: -Oxide build up on O2 sensor (clean with fine sandpaper) -Proper Flame sense microamps (.5 microamps minimum) -Gas stuff ( I think is fine) Green wire (ground?) check Inadequate flame carry over or rough ignition. Plan to clean O2 sensor (where?), check my ground and replace the filter. Also while every thing is open give the blower and other dusty components a good dusting. You guys know, what else do I need to do, check, etc. DOMO arigatou. Tsuriman