Got a furnace problem that has me running in circles. Perhaps some
quick advice can point me in the right direction at least. We have a
Carrier furnace, older that 5 years old, and this year is has been
failing to ignite, flashing error code 14 (ignition lockout) causing
it to wait 3 hours before the next attempt. FYI here is the code
#14 default= ignition lockout, control will reset after 3 hours. Refer
#34 default= ignition proving fault. Check for gas valve turned off,
oxide build up on flame sensor, main shut valve turned off, Green wire
must be connected to furnace sheet metal, proper flame sense microamps
(.5 micro amps DC minimum), inadequit flame carry over or rough
ignition, low inlet gas pressure.
Now, a little history:
1) Four years ago we had a crawlspace dug out and the project and the
project went poorly, causing the basement to be exposed to excessive
dust and moisture for much of that winter.
2) This winter we began having trouble with the thermostat. The
backlight would not light, it would display gibberish, and sometimes
not display anything. Shortly thereafter we noticed that this
behavior happened at the same time the furnace had the ignition
3) We called an independent contractor and described the problems.
The tech wasn't aware or (or wasn't concerned with) the codes and was
only concerned with the thermostat. He indeed found and straightened
some bent pins and we could notice a tighter fit when we closed the
cover of the stat. He figured that solved the problem, and he never
even looked at the furnace itself.
4) A month later the lockout recurred, and the contractor sent another
guy on the callback. The furnace had restarted by then so he didn't
see the codes, and I don't think we mentioned them when we made the
emergency call. Anyway, he was certain it was an overheating issue
and when he went in he found the coil was *very*
dirty (from the
crawlspace project) and had to scrape it with cleaning solution.
5) Now, another month later, the problem has returned.
I don't know which direction to take this. I don't want to keep bring
techs out who don't fix the root cause (whatever it is). Before I
invest in another call, perhaps someone could tell me:
- Could this problem really be caused by a defective stat or dirty
coil? The stat HAS been loose and the coil HAS been dirty, but the
error codes don't mention these, and don't seem to allude to them.
For that matter, if the ignition is locked out, will it cause the stat
to act funky when I use it? I don't want to pay for another scraping,
or a new coil, if I don't have to.
- If I call the techs back, after I make sure they are aware of the
codes, what directions should I give them?
- Is there anything I can check on my own fairly easily before
resorting to another callback?
Thanks for any advice,