English (GB)
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10. How it works
This section gives a short description of how the different pump
functions work.
Pump functionality
• To achieve 0.5 l/min. to turn the flow switches on, there must
be a minimum height between the bottom of the cold-water
storage tank and the highest point of the outlet pipe or the
shower outlet of at least 250 mm.
• The pump control will automatically turn the pump on and off
when water is consumed. The power supply to the pump can
therefore be left on at any time.
Use of flanges
• We do not recommend that you take the hot-water supply
directly from the top of the hot-water cylinder, as entrapped air
may cause problems such as airlocks in the supply pipe.
• Excessive air entering the pump will cause faulty operation
and damage to the pump seals which will cause water leaks.
Valves
• Do not fit any non-return valves in the inlet pipe as the pump
must be able to vent back to the cold-water storage tank and
hot-water cylinder.
10.1 Universal-head pumps
• All air must be thoroughly purged from the system. If air is
present in the pump, it will be unable to generate sufficient
pressure to operate the pressure switch. This will cause the
pump to run or pulse continuously.
• Any leak or drip will cause the pump to operate periodically,
the frequency dependent on the rate of the leak.
Pressure and flow control
Shower pumps for universal-head applications are controlled by
both water pressure and water flow.
Twin-impeller pumps incorporate two separate pressure and flow
control systems, one on each pump end, ensuring complete
isolation of hot- and cold-water systems and consistent operation
over a wide range of unbalanced flow rates.
The control system manifold includes an integral non-return valve
to maintain system pressure when water is not flowing.
Operation
The pressure switches start the pump on falling pressure. The
switch point is factory-set.
Once the pump has been started by the pressure switches, the
flow switches maintain the pump running, providing the flow rate
is above 0.5 l/min. When the flow rate drops below 0.5 l/min., or
the demand is turned off, the pump will stop after first running on
for three seconds to recharge the pressure tanks.
11. Engineer check list
• Minimum 227 litres (50 gallons) of water of stored cold water.
• 22 mm pipes if the pump is rated 2.0 bar or greater.
• Dedicated, independent supply from hot-water cylinder and
cold feed from tank.
• At least 2 m head from water level in cold-water storage tank
to top of pump (1 m on SSR2, STR2, SSP, STP, SSN and STN
pumps).
• Anti gravity loop if the pump is sited above hot-water cylinder.
• The pump must not be connected directly to mains pressure
water (Combi, Unvented, Thermal Store, etc.).
• Highest point of pipes must be at least 250 mm below the base
of the cold-water storage tank (not applicable for universal-
head pumps).
• Hot-water temperature must not exceed 60 °C (cylinder must
have thermostat).
If correction of any of the above did not ensure successful
operation, please call 01525 775460 in UK or 01-4089800 in ROI
to speak to a technical advisor.
12. Maintenance and service
• Inspect all flexible hoses and connections at least every six
months, as water temperature and mechanical stress, can
cause the hoses to deteriorate with age. Replace as
necessary to prevent leaks. Only hoses designed for the pump
can be used.
• Clean strainers every six month, or when needed.
If the flow from the shower drops below its normal
performance, it may be necessary to clean the pump strainers.
Blocked strainers are common on initial installation of pumps,
or in new buildings where the use of jointing compounds,
tapes, flux and other debris can be flushed through the
system.
In this event, close the isolating valves, remove and clean the
strainers. See section
6. Startup
.
• Washers and seals must be replaced when necessary to
prevent leaks or drips.
• If the supply cord is damaged, it must be replaced by the
manufacturer, the service agent or similarly qualified persons
in order to avoid a hazard.
• A common cause of poor shower performance is a clogged
shower head/handset, so regular cleaning and descaling is
important. This applies particularly to hard-water areas.
• If you have any questions, please contact the Service
Helpline: UK: 01525 775460. ROI: 01-4089800.
Tank air-pressure setting (universal-head pumps)
The pressures are factory-set. In the event of a leak, they should
be set as follows:
The smaller tank (300 ml) should be set at a pressure between
0.9 and 1.0 bar. The larger tank (500 ml) should be set at a
pressure between 0.5 and 0.6 bar.
13. Disposal
This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest Grundfos company
or service workshop.
The crossed-out wheelie bin symbol on a product
means that it must be disposed of separately from
household waste. When a product marked with this
symbol reaches its end of life, take it to a collection
point designated by the local waste disposal
authorities. The separate collection and recycling of such
products will help protect the environment and human health.
If correction of any of the above did not ensure
successful operation, please call the Service
Helpline before removing the pump from the
installation:
UK: 01525 775460
ROI: 01-4089800
It is important that the total head on the pump is less
than 8 m. Otherwise, the pressure switch can never
operate and hence the pump will fail to start.
In certain applications, for example steam cabinets, it
may be necessary to increase the pressure. Consult
the appliance manufacturer.
Summary of Contents for SSN
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