Weil-McLain Boiler - Manual (Page 27)

Part Number 550-110-646/0607
Universal control systems — Control supplement
Troubleshooting
Burner access panel must be in posi-
tion during boiler operation to prevent
momentary flame rollout on ignition of
main flame. Severe personal injury or
substantial property damage will result.
Never jumper (bypass) any device ex-
cept for momentary testing as outlined
in Troubleshooting Charts. Substantial
property damage and/or severe personal
injury could occur.
Label all wires prior to disconnection
when servicing controls. Wiring errors
can cause improper and dangerous opera-
tion.
Verify proper operation after servicing. See
vent damper manufacturer’s instructions
packed with vent damper for additional
information. Failure to comply could
result in severe personal injury, death or
substantial property damage.
Before troubleshooting
1. Have a voltmeter that can check 10 VAC, VAC,
and a continuity tester.
. Check for 10 VAC (minimum 10 to maximum
1) to boiler.
. Make sure thermostat is calling for heat and contacts
(including appropriate zone controls) are closed.
Check for VAC between thermostat wire nuts and
ground.
In event of vent damper failure:
Effikal or Field Controls vent damper
If troubleshooting chart recommends replacing actuator and actuator is
not immediately available, damper blade can be fixed in an open position
to allow boiler operation. Manually turning blade can cause actuator
damage . Follow these instructions only in case of no heat or damper
actuator malfunction.
1. Move damper service switch to
Hold Damper Open position. Apply call
for heat to boiler. Damper blade should then rotate to open position
and boiler will fire.
. If step 1 does not open damper, manually rotate damper blade to open
position using wrench or pliers on flat shaft between damper and actua-
tor. Boiler will fire. Verify that damper service switch is in Hold Damper
Open position (Figure 11).
. Do not leave vent damper permanently in this position. Replace actua-
tor immediately. If vent damper is left in open position, boiler will not
operate at published efficiencies.
Johnson Controls vent damper
If troubleshooting chart recommends replacing actuator and actuator is
not immediately available, damper blade can be fixed in an open position
to allow boiler operation. Follow these instructions only in case of no heat
or damper actuator malfunction. See Figure 11.
1. Turn off power to boiler.
Failure to turn off power to boiler can result in severe personal
injury, death or substantial property damage.
. Refer to vent damper manufacturer’s instructions for procedure to fix
vent damper in open position.
. Turn on power to boiler.
. Using wrench or pliers on flat shaft section, manually rotate damper
blade until green light turns on. Boiler will fire (Figure 11).
. Do not leave vent damper permanently in this position . Replace
actuator immediately. If vent damper is left in open position, boiler will
not operate at published efficiencies.
Figure 11 Manually opening vent damper