Boiler Manual
11c Troubleshooting — control module
Make sure ground wiring is installed per wiring diagram. Good grounding is extremely important for proper operation.
Solder or water splatter between plugs and circuit board can cause improper operation of control module. Place a shield over the boiler internal controls and components during installation. Failure to comply could result in severe personal injury, death or substantial property damage.
Control indicator lights — lockout modes
See Charts 1 through 7 in this section for detailed troubleshooting procedures.
To reset control after a lockout, turn off power at the 120 VAC service switch or turn down all thermostats.
Wait 45 seconds. Then restore power or call for heat.
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POWER light flashing alone
Usually indicates reversed polarity of 120 VAC power wires.
POWER and TSTAT CIRC lights flashing
Usually indicates stray voltage on external thermostat circuit wires (usually due to miswired
POWER and PRESS SWITCH lights flashing
Usually indicates pressure switch is closed when it should not be, or pressure switch failed to close within 5 minutes of inducer starting.
POWER and FLAME lights flashing
Usually indicates false flame sense or flame sensed when it shouldn’t be there.
Part number
Control indicator lights — non-lockout modes
FLAME light flashing alone
Usually indicates pilot flame was not established within 15 seconds from application of spark. Control will flash light, but will continue to cycle indefinitely until flame is established or problem is corrected.
PRESS SWITCH light flashing alone
Usually indicates pressure switch opened during the run cycle.
Troubleshooting the control module
See Figure 25 for location of harness plug receptacles and plugs on the control module.
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