Grundfos SSL 1.4 C Installation And Operating Instructions Manual Download Page 4

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4. Positioning the pump

Minimum inlet pressure: 2 metres (recommended).
Keep the pump as close as possible to the source of hot and cold
water.
For optimum performance, ensure
• a good water flow to the pump
• sufficient head
• unrestrictive pipework
• provision to prevent air locks.
Place the pump in a well-ventilated location, e.g. on the floor of
the airing cupboard.

The pump must be mounted horizontally with discharge ports
vertically upwards to ensure correct operation of the flow
switches.
To reduce noise, we recommend the pump be mounted on a
small concrete foundation of approximately 225 x 225 mm and
40-50 mm thick.
Connect the pump and shower system as shown in fig. 2,
page 12.
To achieve 0.5 l/min. to turn the flow switches on, there must be a
minimum height between the water level in the cold-water storage
tank and the shower outlet of approximately 250 mm. See fig. 2,
page 12.
The pump must be installed in accordance with the Water Supply
(Water Fittings) Regulations 1999.
For installation within a bathroom, locate the pump in accordance
with the IEE Wiring Regulations seventeenth edition (BS 7671:
2008) Part 6 Section 601 for a shower pump with an IPX2
enclosure. The pump must be positioned at least 0.6 metres
horizontally or 3 metres vertically away from any bath, shower
tray or basin.

4.1 Negative head

If the water level in the cold-water storage tank is below the level
of the shower outlet, this is called a negative-head system. To
enable the pump to operate, a negative-head pump must be
used. See section

2.1 Type key

5. Hot-water cylinder connections

The use of a Surrey flange (see fig. 2, page 12) is recommended
to ensure a free-flowing supply of air-free hot water.
The hot-water supply may be taken directly from the top of the
hot-water cylinder, but entrapped air may cause problems.
22 mm copper pipe should be used to ensure an adequate flow to
the pump. Where high flows are expected, 28 mm is
recommended.

6. Cold-water supply

The cold-water supply to the pump must be connected using
22 mm pipe to the cold-water storage tank. See fig. 2, page 12.
The tank connector should be positioned at least 25 mm (1”)
lower than the cold-water supply to the hot-water cylinder to
prevent the supply of hot water only.

7. Connecting the pump

For ease of installation, subsequent servicing and cleaning of
strainers, full-bore isolating gate valves should be fitted in the
pump suction and discharge ports.

The flexible hoses supplied with the pump must be used for
connecting the pump to the pipework. Use of these hoses will
ensure strain- and vibration-free watertight connections. The
maximum bend angle should not exceed 45 °.
After initial installation, run the pump for a few minutes, switch off,
drain down and clean the suction strainers.
For SSN, SSP, STN and STP pumps, remove the suction hose
from the pump, and the strainer basket can be removed by hand
or with long-nosed pliers.
Line up pipework, and fit hoses to the pump before connecting to
pipes. Position pipework accurately so that the pump is not
subject to mechanical strain.
Plastic nuts should be finger-tight plus 1/4 turn. The nuts should
be retightened after hot water has been pumped for the first time.

7.1 STC, STR, SSR, STL and SSL pumps

The strainers supplied with the pump must be fitted to the pump
suction connections only with the wire dome towards the pump.
See fig. 1.

Fig. 1

Fitting the strainer

Note

Select a position for installing the pump which
affords easy access for subsequent servicing
and maintenance.

Caution

Do not cover the pump, otherwise the motor will
overheat.

Caution

The pump must be placed in a frost-free location.

Warning
The pump may be fitted under a bath, providing
this space is only accessible through the use of
a tool. If in doubt, consult the Wiring Regulations.

Note

If the pump is positioned above the outlet of
the hot-water storage cylinder, ensure that the
pipework to the pump from the cylinder has a
downward loop. This will help prevent air locks.

Caution

Do not use any jointing compounds.

Caution

Do not connect the pump directly to the water
mains supply.
Do not use any jointing compounds or tape.

Caution

Do not use any jointing compounds or tape.

Note

Isolating valves greatly assist draining down,
strainer cleaning and refilling, which will result in
much lower service costs.

Note

Do not bend hoses as this will cause restriction
of flow.

203

Discharge
connection