B&D Mfg HSS - Manual (Page 5)

5
PURGING HSS
®
BUFFER TANK
The HSS
®
Buffer Tank can have several loops or circuits and each one
should be purged separately. The HSS Buffer Tank shall be filled with water
prior to running any of the circulator pumps. Keep a water source nearby to
fill the tank as necessary. As air is relieved from the system piping water will
need to be added. Prior to running any of the pumps except the 15-58
pumps, the large metal screw on the back of the Grundfos pump shall be
removed, and the pump shaft turned by hand to allow air to be purged from
the pump. ( Check 3– speed pump for right setting.)
Turn on the 1
st
zone pump, by jumper or thermostat, and monitor the water
level in the HSS
®
Buffer Tank, as the water level drops in the Buffer Tank,
add water to maintain a minimum level of water in the tank. A minimum
level would be just below the return line pipe discharge point. The reason for
a low water level while filling is to allow air to vent without splashing water
out of the Buffer Tank. When the water level rises, 1-2" above the discharge
point in the Buffer Tank then shut off the 1st zone circuit and start the 2
nd
zone circuit process. Repeat this process until all zones have been purged.
It is important to note the arrow on the pump should be pointing up this will
ensure proper flow direction. The isolation pump flanges should be turned
on. This is accomplished when the line on the valve is parallel with the pipe
direction. There may be occasions when a pump for an air handler is located
two stories above the HSS
®
Buffer Tank and will not have enough head to
purge the air out of the line. In those cases turn the isolation valve shut and
pull out the smaller pump and bolt in a larger pump and open the isolation
flanges. Once the air handler has been purged, then shut off the isolation
valves on the flanges. Unbolt the temporary pump and bolt in the permanent
pump, open the isolation flanges while pump is running open bottom flange
first. Once the pump runs and pushes a small amount of air out of the system
the pump will maintain the prime. If you should loose prime on this circuit
you would need to re purge as described above. When all the hydronic zones
are purged then move to the water-to-water heat pump manifold and start the
purging process as started with the zone pumps. Be sure to purge the air out
of the pumps first.
WARNING: HSS
®
Buffer Tank is a non-pressurized unit and should never be pressurized.