Weil-McLain SERIES 7 PFG - Manual (Page 13)

13
PFG S
erieS
7 G
aS
-
Fired
W
ater
B
oiler
– U
niverSal
C
ontrol
S
yStemS
Part Number 550-110-643/0605
Check for open thermostat or circ. relay (where used) or check for
loose wire connections, defective spill switch or rollout thermal fuse
element, or open LWCO or hight limit contacts.
If LWCO, spill switch or rollout thermal fuse element
contacts are open, determine cause and correct
condition. Failure to do so will cause severe personal injury, death,
or substantial property damage.
Is damper harness securely plugged in at both
ends?
No Yes
Secure connections.
TABLE II: No Spark, System Does Not Work
With Vent Damper
Is 24VAC present across terminals C and Y on
transformer?
No Yes Check for loose wire connections
or bad relay on transformer.
Is 24VAC present across terminal C and yellow wire
between damper connector and rollout thermal fuse
element?
No Yes
Replace actuator.
Check for out of round stack section.
Does motor rotate open?
No Yes
Is damper rotated open?
No Yes
Open thermostat contacts for 30
seconds. Damper will rotate to closed
position. Close thermostat contacts.
Damper will rotate to open position..
Is 24VAC present across terminals PV
and MV/PV?
No Yes
Is 24VAC present at Terminals
PV and MV/PV?
No Yes
Is spark present now?
Yes No
Re-test.
Turn OFF supply voltage.
Check continuity of each wire in wiring
harness to damper. Does continuity exist
for each wire?
No Yes
Replace damper
wiring harness.
Securely connect and
turn
ON supply voltage.
Re-test.
Check spark wire. Is it securely
connected to ignition control?
No Yes
Is condition of spark
wire good (not brittle,
burned or cracked)?
No Yes
Remove damper harness from boiler
wiring harness. TEMPORARILY install
jumper between terminal 2 and
terminal 5 on damper plug in boiler
wiring harness. See Figure 10. Does
boiler fire?
No Yes Replace pilot assembly.
Replace ignition control.
Replace actuator.
Is spark gap 0.125" and
located in pilot gas stream?
No Yes
Replace pilot assembly.
Replace ignition
control.
Is spark electrode ceramic
cracked?
No Yes
Replace pilot assembly.
Turn ON supply voltage
and operate system
several complete cycles.