52
C. Trouble shooting problems where a hard lockout code is displayed. When a hard lockout occurs, the boiler
will shut down and the display will flash the letter “E” followed by a two digit service code. Once the condition
that caused the lockout is corrected, the boiler will need to be manually reset using the RESET button on the
display.
CODE CONDITION POSSIBLE CAUSES
E 00
A flame signal was present when there should
be no flame.
• Defective gas valve - make sure inlet pressure is below maximum
on rating plate before replacing valve.
E 02 Flame failure after 5 tries to restart
• No gas pressure
• Gas pressure under minimum value shown on rating plate
• Gas line not completely purged of air
• Defective Electrode
• Loose burner ground connection
• Defective Ignition Cable
• Loose or defective gas valve harness
• Defective gas valve (check for 24 VDC at harness during trial for
ignition before replacing valve)
• Air-fuel mixture out of adjustment - consult factory
• Blockage in vent system or heat exchanger (BWC 150 Only)
• Blocked condensate trap (BWC150 Only)
E 03 Internal control failure • Reset the control. If problem reoccurs, replace the MCBA.
E 04 Power failure occurred after lockout
• Some other error on this list occurred and power to the boiler was
then interrupted. Reset control and see if hard lockout reoccurs.
E 05
E 06
E 07
E 11
Internal control failure • Reset the control. If problem reoccurs, replace the MCBA.
E 12 Low water cut-off circuit open
• If yellow light on LWCO is on, system is low on water
• If neither yellow nor green light is on, check LWCO harness and
check for 24VAC across AT140 transformer
E 13
E 14
E 15
E 16
E 17
Internal control failure • Reset the control. If problem reoccurs, replace the MCBA.
E 18
MCBA supply sensor detected temperatures in
excess of 200°F for an extended period of time
• See possible causes for “b18” error. Also, check safety limit for
proper operation.
E 19
MCBA return sensor detected temperatures in
excess of 200°F for an extended period of time
• See possible causes for “b19” error.
E 28
Blower is not running when it should or fan
speed signal not being detected by MCBA
• Loose connection in 120 VAC fan wiring
• Loose or miswired fan speed harness
• Defective fan
E 29 Blower fan speed has not returned to zero rpm
• Miswired fan speed harness
• Defective fan
E 31 Shorted supply temperature sensor
• Shorted or miswired supply sensor wiring
• Defective supply sensor
E 32 Shorted return temperature sensor
• Shorted or miswired return sensor wiring
• Defective return sensor
E 35 Flue gas temperature sensor short circuit
• Shorted or miswired flue temp sensor wiring
• Defective flue temp sensor
E 36 Supply water temperature sensor circuit open
• Loose or miswired supply sensor wiring
• Defective supply sensor
E 37 Return water temperature sensor circuit open
• Loose or miswired return sensor wiring
• Defective return sensor
E 40 Flue gas temperature sensor circuit open
• Loose or miswired flue temp sensor wiring
• Defective flue temp sensor
E 44 Internal control failure • Reset the control. If problem reoccurs, replace the MCBA.
E 52 Flue gas temperature over 230°F
• Heat exchanger needs to be cleaned
• Boiler over-fired
• Air-fuel mixture out of adjustment - consult factory
E 60 Internal control failure • Reset the control. If problem reoccurs, replace the MCBA.
Table 13.4: Hard Lockout Codes Displayed
