Installation / Operation Instruction Manual

43
Error
Code
Definition of Code Cause of Problem and Actions Taken to Correct
105
Flame detected out of
sequence
 Check to see if flame is present inside the combustion chamber before or after the
ignition cycle.
 If so, check to make sure the gas valve is wired correctly.
 Check for voltage at the gas valve connection.
 Replace the gas valve if defective.
 If no flame is visible outside of the ignition sequence/run cycle, then make sure the
flame sensor is wired to the correct terminal.
 Make sure the ignition cable is not crossing the flame sensor wire or ignition ground
wires.
 If problem persists and all other checks have been verified, replace the control
module.
109,
110
Ignition Failure
Occurred.
 Burner failed to light or stay lit after 4 retries.
 Hold condition – will reattempt ignition after 15 minute waiting period. A log will be
stored in service history.
 Check gas valve wiring and gas valve operation during the ignition cycle.
 If burner lights but quickly goes out, check the flame sensor wire or the flame
sensor.
 If the flame sensor rod is badly corroded with deposits, clean with sandpaper or
replace.
 Check the inlet gas supply to make sure the pressure is sufficient and does not
drop after the gas valve opens.
 Make sure the combustion blower is operating during the ignition and run cycle.
 Check the venting system to make sure the inlet and exhaust terminals and venting
system is not blocked.
122,123
Light-off Rate Proving
Failed
 If blower speed is not verified from the PWM (Pulse Width Modulation) signal within
5 minutes, the previously described error code “62” changes from a hold condition
to this lockout code condition
 Check the harness and pin terminals for a good connection to the control module.

Replac
e the blo
w
er
or control module if the wi
re harness is good.
172
Water temperature
sensor resistance
invalid
 Hold 93 will be displayed if this value remains out of range
 Measure the resistance of the water temperature sensor and compare it with the
tank temperature using the chart below.
NOTE
 If there is do display, check primary/secondary voltage
 Before troubleshooting always verify the following
o Gas inlet pressure
o Static to dynamic gas pressure drop
o No vent and intake restrictions
o All wire connections are tight
o No grounded wires or missing grounds
o
No water leaks