Dunkirk WPSB Series II - Manual (Page 26)

26
BLOCKED VENT SAFETY SWITCH
(BLOCKED VENT SAFETY SHUTOFF)
Blocked vent safety switch is manual reset disc thermostat
with fi xed setpoint (340°F), and normally closed contacts. It
is located at relief opening of integral draft diverter. In event
of chimney or venting system blockage causing products of
combustion to spill out of relief opening, blocked vent safety
switch disc heats up and blocked vent safety switch contacts
open, shutting down fl ow of gas to main burners by removing
power to gas valve.
In event blocked vent safety switch contacts open, reset
button on back of switch will pop up. Blocked vent safety
switch must be reset manually, after switch has cooled off,
by pushing reset button down. Check venting system and
chimney for blockage when restoring system to operating
condition. DO NOT operate boiler without blocked vent
safety switch.
ROLLOUT SWITCH
(FLAME ROLLOUT SAFETY SHUTOFF)
Rollout switch is temperature-sensitive fuse link device.
Located on boiler base just outside fi re box. In event of
heat exchanger fl ueway blockage causing fl ame to roll
out of fi re box, fuse does not change in appearance when
blown.
If rollout switch blows, it must be replaced with exact
replacement. Check heat exchanger fl ueways for blockage
when restoring system to operating condition. DO NOT
operate system without rollout switch.
EQUIPMENT AND OPTIONAL ACCESSORIES