12 • Condensing Models: On-Demand Water Heater Service Handbook
TR
OUBLE
SHOO
TING
Incorrect DIP Switch Se ngs
Error Code: 031
1. Turn off the power supply.
2. Remove front cover and locate the
DIP switches at the bottom of the
computer board.
3. Refer to “Table 5: DIP Switch
Settings”, p. 19.
Table 5 lists the
correct DIP switch positions.
NOTE:
Before you change the DIP
switch settings, turn off power
to the heater by using the switch
above the computer.
Abnormal Combus on
Error Code: 101
This code is a warning that the air-
fuel ratio for combustion is gas rich.
The heater will continue to operate
with this error code, but a shutdown
is imminent if the problem is not
resolved. The next step is a 991 error
code which will force the water heater
to shut down.
Refer to “Error Code: 991,“ page 17.
Igni on Failure / Flame Loss
Error Codes: 111 or 121
Either the water heater will not
fire after three failed attempts at
ignition (code 111) or it is not firing
consistently (code 121).
These codes can appear due to a
component in the heater or due to an
external cause, such as no gas supply.
These codes will automatically reset
when water stops moving through the
heater or when the power is turned
off, then back on again.
1. Verify that the gas supply pressure is
within specifications when the heater
is in standby and when the heater is
trying to light. Also, verify that the
gas line is cleared of debris.
•
It is possible that there is a faulty
pressure regulator at the gas
meter.
•
For propane units, colder
periods of the day result in a cold
regulator and may cause this
problem.
2. Check the High Limit Switch and
Overheat Cutoff Fuse (OHCF) as follows:
•
Turn off power to the water
heater, then turn it back on. (Use
the switch above the computer
board.) Listen for the “clunking”
noises of the gas solenoid valves.
If you DO hear them, skip the
remaining bullet points and go to
step 3.
•
Turn off power to the heater by
disconnecting the power cord or
external switch.
•
Locate the high limit switch (item
411, p. 70). See also Figure 24
on page 35.
Push the button in the middle of
it. The switch was reset if you
heard and felt the button click.
Turn the power back on and test
the heater. If the unit fires on,
the cause of the high limit trip
must be determined. Continue
with the troubleshooting
process.
If the high limit switch trips
again, replace the high limit
switch (part number 319143-
228) However, if the high limit
switch tripped and the heater
is in a hard water environment,
the heater may be scaled up.
See “Descaling the Unit” on
page 29.
•
Refer to “Checking the Overheat
Cutoff Fuse (OHCF)” on page
27.
3. Make sure that the clear plastic
tube connecting the proportional
gas valve to the combustion
chamber is attached. See Figure 6.
If necessary, see also Figure 33 (p.
41) and Figure 37 (p. 42).
4. Check the igniter for a spark. The
spark may be viewed through the
sight glass located next to the
igniter and flame sensor. A strong
blue spark will remain steady and
in place, while a weak spark will
jump around.
4.1
If no spark or a weak spark is
observed, check the igniter
wire connec ons and make
sure that these are secure.
4.2
Check the igniter rod to
make sure the black wire is
properly a ached and that
the rod doesn’t move. If it
moves, replace the igniter
rod, part 320273-357. You
will also need a gasket, part
319143-034.
4.3
When the igniter is sparking,
check the voltage across the
purple wires coming to the
igniter. Normal voltage is
108-132 VAC. If voltage is
outside of this range then
replace the computer board,
part #320273-369.
4.4
If the previous steps s ll
don’t result in a spark being
generated, replace the
igniter (part 320273-381).
5. If flame comes on for only 1-2
seconds before going out, verify
that the green IN USE LED on
the built-in controller or remote
controller did not turn on. If the
LED stayed off, then inspect the
flame sensor. Clean it if necessary.
Replace it if any damage (chips
or cracks in the ceramic) is seen
or if the metal rod can move
