furnace codes

oldtown

what does the 2 flash code external lockout mean on a american standard freedom 90 vs two stage furnace lite for a while the burner stopped and blows cold air for long time

Done That

Theres an external limit switch open, or the board has gone past the maximum number of retry/recycle attemps to establish flame or not lose flame after a certain time.

After an hour in external lockout the control should automatically attempt trial for ignition again. Cycling power restarts all of these counters and timers but of course does not resolve the root problem and can cause even more issues.

You may want to just get a tech involved now, be safe with gas and don't waste a lot of time changing parts needlessly.....

Sorry, also meant to add it certainly would be worthwhile to inspect and clean the flame sense probe if this unit has been in for awhile, some fine steel wool or a scotchbrite pad will do.

ben's plumbing

you should have a chart of codes on inside of upper or lower door panels...ben sr

oldtown

cleaned flame sensor ran fine for a while then stopped again could it be a bad flame sensor?

Marty S.

Not likely. A flame sensor is just a steel rod. About the only thing that can go wrong with one is the insulation cracks.

oldtown

i kinda thought so wishfull thinking hope its not contol board