Stuart Turner Monsoon U1.5 bar Twin Installation Instructions Manual page 4

Fig. 3
If it is not possible to locate the pump in the preferred area due to site limitations and it
is necessary to position the unit in the loft, or in a position above the secondary tapping
that feeds the pump, then there is an increased risk of air locks. This risk must be
eliminated.
The following measures are suggestions that may overcome the problem:
1) A "U" bend or downward loop in the supply pipe to the pump of 350 mm depth before
rising to the pump should ensure the cylinder vents its air up the expansion pipe not
up the pump feed (Fig. 4).
2) An alternative to the above would be the installation of an automatic air vent situated
at the top of a vertical pipe run directly connected to the pump discharge. This will
ensure any air collecting in the pump is automatically vented.
Fig. 4
hot water
services
hot water
services
(shaded area). Pump at a level
below draw off tapping in
cylinder.
- 4 -
Preferred Pump Location
Model Max. inlet Max. outlet
head head
U1.5
U2.0
8 m
U3.0
U4.0
12 m
U4.5
Table 1
Note: If installed in loft
there must be a height of
200 mm from water surface
to the highest point of the
hot or cold inlet pipework at
all times to prevent air
locks.
Least Preferred Pump
Location (shaded area).
Pump located above the hot
cylinder can increase the
risk of air locks.
8 m
12 m