Part 12: Troubleshooting; Mod Con Error Code; Boiler Error; Boiler Fault - Heat Transfer MODCON VWH 300 LP Installation & Maintenance

PART 12: TROUBLESHOOTING

A. MOD CON ERROR CODE
If any of the sensors detect an abnormal condi-
tion or an internal component fails during the
operation of the Mod Con Boiler, the display
may show an error code. This code may either
be the result of a temporary condition in which
case the display will revert to its normal readout
when the condition is corrected or it may be the
result of a condition that the controller has eval-
uated as not safe to restart the boiler. In this
case, the boiler control will be locked out,
requiring the maintenance person to manually
reset the control by pressing the {S4/RESET} but-
ton for more than 1 second. Typically, if the dis-
play has a code beginning with F followed by 2
numbers the Mod Con Boiler is locked out. If the
display has a 3 letter code it is the result of a
temporary condition.
B. BOILER ERROR
When an error condition occurs, the controller
will display an error code on the display module.
These error codes and several suggested cor-
rective actions are included in Table 12-1.
GAS-FIRED HOT WATER SUPPLY BOILER
C. BOILER FAULT
1. When a fault condition occurs the controller
will illuminate the red "fault" indication light
and display a fault code in the format. The
alarm output will also be activated. Most fault
conditions will also cause the CH pump to
run in an attempt to cool the boiler.
2. Note the fault code and refer to Table 12-2 for
an explanation of the fault code along with
several suggestions for corrective actions.
3. Press the reset key to clear the fault and
resume operation. Be sure to observe the
operation of the unit for a period of time to
assure correct operation and no re-
occurrence of fault codes.
n
WARNING
When servicing or replacing any components of this
boiler be certain that:
• The gas is off.
• All electrical power is disconnected
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