Relay Control - Dunkirk Empire II Installation & Operation Manual

MAIN AIR VENT: for down flow systems or diaohraam tvoe exoansion tanks (not
orovided_ Before a system is filled with water, there is air in the pipes and radiation units.
Some of the air will be trapped as the system is filled. It is possible to eliminate most of this
air through the air vents on the radiation units. A main air vent will speed and simplify this
process. The main air vent should be installed on the highest point in the supply main when
all radiation is below the top of the boiler.
AUTOMATIC FILL VALVE (not provided)
For safe, efficient operation, a hot water system must be filled with water. Adding new
water, when needed can be done manually (by use of a hand valve in the water supply line).
This requires regular attention to the system's needs. An automatic fill valve or pressure
reducing valve accomplishes this without attention. It is installed in the supply line on hot
water boilers only. The valve operates through water pressure differentials. It does not
require an electrical connection.
BURNER SOLENOID VALVE (provided)
The Beckett and Carlin oil burner's use a standard solenoid valve. Upon burner shut down, a
standard solenoid valve stops the flow of oil to the nozzle. Without the solenoid valve, the oil
pump continues to pump oil to the burner nozzle until the burner motor winds down below the
pumps cut-off speed. The Riello oil burner has a delay solenoid valve. The delay solenoid
valve provides the same shut down action as the standard solenoid valve, plus on burner
start up the delay solenoid valve remains closed for an additional 15 seconds. This allows
the burner fan motor to pre-purge the combustion chamber and the oil pump to bring the
supply oil pressure up to its set point helping to provide a clean light off.
AQUASTAT RELAY CONTROL (provided)
The water temperature limit control in the aquastat relay is adjustable and may be set: as
low as 140°F so long as return water temperatures to the boiler are no less than 120°F, or
as high as 240°F so long as the boiler and heating system have adequate circulation to
remove the heat from the boiler otherwise steam may be created in the boiler. Refer back to
SYSTEM PIPING section for more information.
DRAIN VALVE (provided)
The drain valve is a manually operated valve that provides a means of draining all the water
from the boiler and heating system. It should be installed in the reducing tee where the
return line enters the boiler.
CIRCU LATOR (Drovided_
Every forced hot water system requires a circulator. A separate circulator or zone valve is
required for each zone, if there are two or more zones. The circulator must have the capacity
to provide the circulation required by the heating system. The circulator should be connected to
the supply main and must be wired into the boiler's electrical system. See the SYSTEM
PIPING section for piping configurations with the circulator located on the supply main piping
using zone circulators or zone valves. When the piping is arranged with zone circulators and no
bypass piping, the circulator provided with the boiler may be used as a zone circulator. Both
piping arrangements allow the circulator to pump away from the expansion tank and show how
the piping should be arranged to allow the heating system to be easily purged of air.
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