Filling The Boiler - Dunkirk Empire II Installation & Operation Manual

FILLING THE BOILER
HOW A HOT WATER SYSTEM OPERATES
The entire heating system (boiler, piping, and radiation units) is filled with water. As the
water in the boiler is heated, it is circulated from the top of the boiler through the supply
main to the radiation units. The cooler water in the radiation units flows back through the
return piping through the return main into the boiler. This arrangement provides positive and
rapid response to the thermostat.
FILLING THE SYSTEM WITH WATER
OPTION #1- This method utilizes the boiler piping as shown in the figure on the previous page.
a) Close the main shutoff valve, isolation valves, and zone valves (if applicable). If bypass piping
is installed, also close the two throttling valves. Leave the boiler service shutoff valve (if
installed) and the balancing valves to each heating zone fully open.
b) Open the following valves in order: the drain valve for power purging, isolating valves
before and after the boiler circulator (if applicable), both throttling valves (if applicable),
and then open the fill line shutoff valve. Water will fill the bypass piping and push the air
through the piping and out the power purging drain valve. When the power purging drain
valve runs air free, close the bypass piping throttling valve (leaving the throttling valve to
the supply piping fully open).
c) Next, open the isolation valve (or zone valve) to the first zone. Water will fill the piping and
push any air out the power purging drain valve. When the power purging drain valve runs air
free, close the isolation valve or zone valve). Repeat this procedure for the remaining heating
zones.
d) Once all zones are filled with water and purged of air, close the power purging drain
valve and fill line shut off valve, open the main shutoff valve, and adiust the throttling
valves and balancing valves as required.
OPTION #2 - Close the air vents on all radiation units. Open the valves to the radiation units.
Make sure the boiler drain valve, expansion tank drain cock, and the air bleed screw on the
expansion tank drain fitting are closed. Open the fill valve on the piping to the expansion
tank. Open the water inlet to the boiler and leave it open. Open the air vent on the lowest
radiation 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 until finishing with the highest radiation
unit. If the heating system has automatic vents, this manual venting is unnecessary but it will
speed up the proper filling of the system.
If the system is a closed expansion tank system, an automatic fill valve is needed. Leave the
automatic fill valve open to refill the system automatically as needed. Note the initial fill
pressure on the boiler's temperature / pressure gauge, which should be 10-15 psig. Any
lowering of the pressure from its initial fill pressure indicates a loss of water due to leakage.
The automatic fill valve should then compensate for this water pressure loss. If it does not,
manually open this valve to refill the system until the needle is again pointing to the same
pressure reading. Instructions are packaged with the valve.
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