en – Original Instructions
Installation, Operation and Maintenance Manual
19
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We recommend, that for pump models with pump housing code BT or BS, you install a ball
shut-off valve before the pump at least, for future maintenance or repair works.
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A properly installed system should include a method of automatically venting the air that
enters the water supply line during use. Air enters the system each time fresh, cold water is
introduced into the hot water heater. Air may also enter the system any time a plumbing line
is opened, for instance during a faucet/taps change or adding a sprinkler system. We
recommend, that for pump models with pump housing code BT or BS, you install an air vent
mounted in a vertical position.
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Pumps with pump housing code BU (item 20 in Figure 3) incorporate a check valve (item 18 in
Figure 3), a ball shut-off valve (item 21 in Figure 3) and a manual air vent valve (item 19 in Figure
3) into the brass pump housing eliminating the need to install these components.
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With the shut-off valve closed at the suction side of the pump and with the check valve
installed at the discharge side, the screw ring (item 5 in Figure 3) can be loosen, thus the
pump motor can be turned in proper position (see section 4.3.3 Rotation of the pump motor
on page 25), or even removed for maintenance (see section 6.4 Disassembly on page 37)
without completely draining the system.
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To be able to exclude the complete unit from the system, e.g. for replacement of the pump
housing without draining the whole system, install additional shut-off valves both at the
suction and at the discharge side of the pump.
The next examples in Figure 5 and Figure 6 show typical installation arrangements for different
return line connection layout, but for single line returns only. For multiple branched supply line
installations, a recirculation line should be installed for each branch.
Figure 5
No. Description
No. Description
1 Tee fitting
7 Circulating pump model BT / BS
2 Hot water return (recirculation) line
8 Ball shut-off valve
3 Hot water supply line
9 Hose bib
4 Cold water supply line
10 Water heater
5 Air vent
11 “Y” fitting
6 Check valve
