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VESSEL PRE-CHARGE PRESSURE
When adjusting the vessel precharge pressure, the vessel connection must effectively be open to atmosphere.
Failure to set the precharge pressure correctly will cause incorrect operation of the Home Booster.
The pressure vessel precharge must be set to 90% of the cut-in pressure setting. Example, if the cuit-in pressure is set to 2.5 bar,
then the pre-charge pressure must be set to 2.5 x 0.9 = 2.25 bar.
The vessel precharge pressure should be adjusted before the pump is filled with water. If the system
has already been filled and the pump run, then:
1. Switch off the pump.
2. Release the water pressure by opening a cold water tap supplied by the Home Booster.
3. The precharge pressure can now be checked using a car tyre pressure gauge. The Schraeder air
valve is located in the top righthand corner of the pump back plate.
4. The tap should be left open while checking and adjusting the precharge pressure.
For small pressure adjustments a foot pump can be used. If large amounts of gas are required then
dry nitrogen should be used in order to prevent corrosion within the vessel.
Operation
The 200 litre integral water storage tank within Home Booster supplies water to the pump though an isolating valve and strainer. A
vent screw is provided for venting the pump on the inlet casting. The pump is controlled by the Grundfos PM2 controller. When
power is applied, the PM2 will sense the discharge pressure, if the pressure is below the set pressure the pump will start. The
pressure will build up in the system, the pump will continue to run until there is a no flow condition. The pressure in the system can
build up to the closed valve pressure of the pump.
The PM2 has built-in pump protection against dry running. The pump will be stopped after 30 seconds, and the red alarm indicator
illuminated, if the pump is running and the pressure remains below the cut-in pressure, with no flow through the pump.
The pump will remain stopped until the reset button is pushed.
FROST PROTECTION
The Home Booster must be protected from freezing conditions. If the booster set is being stored during periods of frost, the tank,
pump and pipework should be drained to avoid damage. Remove all drain and vent plugs and allow the pump to drain. Do not
replace the plugs until the booster set is to be used again.
The pump must be vented/primed before it is started again.
Maintenance
The GRUNDFOS Home Booster has been designed for the minimum of maintenance. However, it should be inspected on a regular
basis. It is therefore recommended that a GRUNDFOS maintenance contract is taken out to cover maintenance of the set. For
further details please contact Grundfos Europump Ltd for on 01942 263628.
However, it is the customer’s responsibility to inspect the Home Booster in addition to any maintenance contract to ensure the safety
and correct operation of the set during the interim period between service visits.
Before removing the terminal box cover from the electric motor or before any removal/dismantling of the pump/motor unit
takes place, ensure that the electricity supply to the Home Booster has been suitably isolated and cannot be switched on.
Care should be exercised when carrying out maintenance work as there may be sharp edges exposed which can cut skin.
INSPECTION
The Home Booster should be inspected at regular intervals, this must be carried out when the Home Booster has been shut down.
The following checks should be carried out at this time.
1. Check that there are no leaks on the internal pipe work, the pump particularly around the shaft seal, and pressure tank.
2. Check for any corrosion particularly on the pressure tank.
3. Check that the pump shaft is free to rotate.
4. Check that water does not appear at the valve on the pressure tanks when the air valve is depressed.
5. Check and adjust if necessary the precharge pressure of the pressure vessel.
6. Check that the pump operate quietly and smoothly without vibration or excessive noise.
Any large deviations from the system values should be investigated for a possible fault. Should any faults be found check the
symptoms with the Fault Finding Chart.
Should any faults be found check the symptoms with the Fault Finding Chart and if necessary contact Grundfos Pump Ltd for advice
or Grundfos Europump for service.
Once inspection and any maintenance work is completed, ensure that the isolating valves are opened fully, and that the electricity
supply to the booster set is restored. Check that the correct system pressure is achieved.
