A. O. Smith Water Products Company
Service Handbook
Irving, Texas 2000©
Training Department
36
BTH COMMON ERROR CODES -
Code 04 - ECO Open
The hi-limit has been tripped or is malfunctioning -- Try to reset the ECO.
Test
to see if ECO is malfunctioning. Also make sure to test the lower temp probe
for continuity. If it has failed the unit may be stacking
Code 02 - Ignition fail after
Has failed to ignite after 3 tries -- Could be a gas pressure problem,
3 attempts
condensate tee, or venting.
Code 05 - Open
Open temperature probe -- the upper temperature probe is malfunctioning
Temperature Probe
(not the lower probe). Test for continuinty thru upper temp probe. An open
circuit means the upper probe and its wiring needs to be replaced. If
continuity is present, check connections to replace board.
Code 11 - Pressure switch
Pressure switch fails to close/open after 5 minutes -- Check condensate tee
fail
and venting. Jump switch temporarily, or test wiht manometer. 90% of the
time its going to be a problem with condensation or venting installation
problem. (too long, too short, manifold venting)
Codes higher than 199 -
These are software errors -- the electric noise is causing unnecessary lockouts.
Replace the board.
Solid "00" or "01" -
The first number which comes up is "00". If the heater is stuck on the startup
Condensate tee
process, you'll get the solid 00. This is an indication that the condensate tee
is clogged.
OTHER SERVICE HINTS
Condenstate tee
BTH produces quite a bit of condensation. If the tee is not installed properly
or kinked or plugged or is going up hill, the venting will fill up quickly and the
problem may be registered as another error.
Chattering gas valve
Low or High supply gas pressure. Possibly plugged condensate hose.
Noisy heater
Short runs on the venting can increase noise. By adding a few elbows
in the venting or extending the run, the noise will diminish. The muffler
will help. Using 4" vent - if possible - may also help.
BTH ERROR CODES
Summary of Contents for BTH 120
Page 65: ......
