Dunkirk PVWB, Installation Instructions Manual

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15
ROLLOUT SWITCH
(FLAME ROLLOUT SAFETY SHUTOFF)
The rollout switch is a temperature-sensitive fuse link device.
It is located on the boiler base just outside the fire box. In the
event of heat exchanger flueway blockage causing flame to
roll out of the fire box, the fuse will blow, shutting down the flow
of gas to the main burners. The fuse does not change in
appearance when blown.
If the rollout switch blows, it must be replaced with an exact
replacement. Check heat exchanger flueways for blockage
when restoring system to operating condition. DO NOT operate
system without a rollout switch.
SPILL SWITCH
(BLOCKED VENT SAFETY SHUTOFF)
The spill switch is a manual reset disc thermostat with a fixed setpoint
(340° F), and normally closed contacts. It is located at the relief
opening of the integral draft diverter. In the event of chimney or
venting system blockage causing products of combustion to spill
out of the relief opening, the spill switch disc heats up and the spill
switch contacts open, shutting down the flow of gas to the main
burners by removing power to the gas valve.
In the event that the spill switch contacts open, the reset button
on the back of the switch will pop up. The spill switch must be
reset manually, after the switch has cooled off, by pushing the
reset button down. Check the venting system and chimney for
blockage when restoring the system to operating condition. DO
NOT operate the boiler without a spill switch.
Starting Your Boiler
HOW A HOT-WATER SYSTEM OPERATES
Your entire heating system (boiler, piping and radiation units) is
filled with water. As the water in the boiler is heated, it is pumped
from the top of the boiler through the supply main to the radia-
tion units. The cooler water in them flows back through the re-
turn main to the boiler. This provides positive and rapid response
to the thermostat.
FILLING SYSTEM WITH WATER
Close the air vents on all radiation units. Open the valves to
these units. Make sure the boiler and expansion tank drain
cocks are closed. The air bleed screw on the tank drain fitting
should be closed. Open the valve in the line from the boiler to
the expansion tank. Open the water inlet to your boiler and
leave it open. Start with the
lowest radiation unit. Open the air
vent on this unit. When all the air has escaped and water starts
to flow from the vent, close it. Go to the next radiation unit, and
repeat this process. Repeat until you have covered every
WARNING
Never run water into a hot empty boiler.
radiation unit in the system (ending up at the highest unit in the
system). If your units have automatic vents, this manual venting
is unnecessary but it will speed up the proper filling of your
system.
If your system is a closed expansion tank system, you may
leave it open to refill the system automatically as needed. Check
the temperature pressure gauge. Not the position of the hand
indicating pressure. This should be between 10 and 15 lbs.
Any lowering of this movable hand below 10 lbs. Will indicate
loss of water due to leakage. The automatic fill valve should
compensate for this. Instructions are packages with the valve.