Bradford White EF120T Installation & Operation Manual With Troubleshooting Manual page 56

Error Code Definition of Code
DHW Sensor Fault
93
(Domestic Hot Water)
Flame detected out of
105
sequence
Ignition failure
110
occurred
Light-off rate proving
122
failed (hard lockout)
Purge rate proving
123
137 Interlock off
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failed
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Cause of Problem and Actions Taken to Correct
Check the sensor wire harness from the DHW sensor to the control
module to ensure there are no loose connections or breaks in the wires.
Check the resistance reading from each of the outside wires to the
center (common) wire.
If the ohm readings are not fairly close, replace the sensor.
Replace the control module if the problem persists and the sensor and
wire connections are not defective.
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.
Burner failed to light or stay lit after 3 retries.
Hold condition – will reattempt ignition after 1 hour waiting period.
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 steel
wool or replace.
Check the inlet gas supply to make sure the pressure is sufficient and
does not drop more than 2" to 3" after 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.
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.
Replace the blower or control module if the wire harness is good.
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.
Replace the blower or control module if the wire harness is good.
Check wiring and correct any possible shorts.
Check Interlock (ILK) switches to assure proper function.
Verify voltage through the Interlock string to the Interlock input with a
voltmeter.
If steps 1-3 are correct and the fault persists, replace the control
module.
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