Weil-McLain GV90+ - Manual (Page 84)

Part number 550-142-054/0411
GV90+
gas
-
fired water boiler
— Boiler Manual
84
Troubleshooting
(continued)
CHART 4 PRESS SWITCH & POWER lights flashing
Electrical shock hazard — Wherever you see TURN OFF POWER, follow the instructions. Failure to follow
instructions could result in severe personal injury, death or substantial property damage.
• Reset boiler control by turning off power at service switch or
turning down thermostat for at least 45 seconds.
• Thermostat should call for heat and appropriate zone valves
open.
Does blower motor operate?
No Yes
• Replace IBC.
• Retest.
• Check air pressure switch per page 75.
• Replace if necessary.
• Retest.
• Clear passages and recycle boiler.
• Recheck boiler operation.
• Properly position blower
wheel on blower motor shaft
and tighten set screw. (Or
replace blower housing
assembly.)
• Retest.
• TURN OFF POWER at
service switch.
• Properly position blower
wheel on blower motor
shaft and tighten set screw.
(Or replace blower housing
assembly.)
• Retest.
• Boiler should be in normal operating se-
quence (Figure 75, page 65).
• Observe operation until thermostat is satis-
fied and blower has completed its post-
purge cycle.
• Replace blower motor.
(Also check blower
housing assembly.
Replace if necessary.)
• Retest.
• Drain condensate.
• Retest.
• TURN OFF POWER at service switch.
Does blower wheel turn freely by hand?
No Yes
• Remove BLOWER plug (Figure 93, page 78, Item 3) from
plug receptacle of IBC.
• Place voltmeter leads across the 120 VAC N and 120 VAC H
pins of the BLOWER receptacle.
Does the voltmeter indicate 120 VAC?
No Yes
• Remove one of the red wires connected to the pressure
switch.
• Check continuity across the switch terminals.
Does the ohmmeter indicate the switch is closed?
No Yes
Is blower wheel turning at speed of blower motor?
No Yes
Is blower wheel turning at speed of blower motor?
No Yes
• Check condensate trap.
Is there condensate present?
No Yes
Are vent or combustion air
passages blocked?
No Yes
• Wait 5 minutes.
Is purge light flashing?
No Yes