Weil-McLain 550-110-260/02002 Boiler User Manual


 
Part number 550-110-260/0200
47
Boiler Manual
continued
CHART 3 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.
Boiler should be in
normal operating
sequence.
Observe operation until
thermostat is satisfied
and inducer has
completed its post-purge
cycle.
Remove one of the wires connected to the pressure
switch.
Check continuity across the switch terminals.
Does the ohmmeter indicate the switch is closed?
Replace control
module.
Retest.
Check air pressure switch
per manual Section 11.
Replace if necessary.
Retest.
Try reseating plug in
module receptacle and
restart.
If inducer still does not
work, replace inducer
assembly.
Retest.
No Yes
Wait 45 seconds.
Does inducer motor operate?
No Yes
Remove INDUCER plug (
Figure 25, Item 6, page 44
)
from plug receptacle of control module.
Place voltmeter leads across the 120 VAC N and
120 VAC H pins of the INDUCER receptacle (left column
center and right column bottom pins).
Does the voltmeter indicate 120 VAC?
No Yes
Are vent or combustion air
passages blocked?
No Yes
Clear passages and
recycle boiler.
Recheck boiler operation.
No Yes
Wait 5 minutes.
Is
PRESS SWITCH
light flashing?
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 inducer motor operate?
No Yes
— Usually indicates pressure switch stuck closed or failed to make within 5 minutes