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Installation & commissioning
General Installation
Pipe fittings
All pipe connections to the cylinder are made via BSP female connection directly to the unit.
Cold Water Supply
The inlet pipe size is best match to the cylinder inlet connection where possible. A 28mm pipe would be the minimum
recommendation but a small pipe may cause more fluid flow noise from the smaller bore due to the increased water
velocity through them.
1” high flow cold water control pack
The control pack consists of a pressure reducing valve with integral strainer, check valve, core unit and expansion valve.
Please note for assembly guidance please see fig 3, page 16.
The pressure reducing valve (see fig 3 page 16) operates between 1.5 - 6 bar and 5 - 10 bar (depending on which cylinder
you have chosen), this is range is clearly indicated on the side of the handle, in order to adjust the predetermined setting
loosen the large plastic screw in the top of the handle and set to the appropriate pressure by rotating the red adjuster at
the top of the gauge as shown on fig 3 page 16. The maximum setting of the valve cannot exceed the cylinder operating
range. For optimum performance the following installation instructions should be complied with.
Installation:
Cold water supply to be sized according to the cylinder.
Flush supply pipework before connection to remove all flux and debris prior to fitting the inlet controls. Failure to do this
may result in irreparable damage to the controls and will invalidate the warranty
The pressure reducing valve can be fitted in any orientation to suit the installation as long as it is fitted in the correct
flow direction. Check the flow arrows on the side of the body
The expansion valve should be installed with the discharge form the expansion valve either horizontal or upright – if
fitted inverted debris may be deposited on the seat when the valve operates. Check direction of flow arrows.
The blank plastic plugs in the body are pressure gauge connections to enable pressure monitoring to be carried out,
should the system develop a fault. It is recommended that these be accessible (the pressure reducing valve has two –
only one need be accessible).
Expansion relief drain pipework must be connected to a safe visible discharge point via a tundish and the pipework must
have a continuous fall. If site conditions allow, the expansion relief drain pipe work can be connected to the T&P valve
drain pipework before the tundish.
Pressure reducing valve:
The pressure reducing valve can be connected anywhere on the cold water mains supply prior to the Andrews water
heater. There is no requirement to site it close to the unit, it can be located at a point where the mains supply enters
the premises if this is more convenient but you must install a non-return valve just after the reducing valve for ease
of maintenance.
The pressure reducing valve can be installed as a complete one-piece unit or incorporating the stopcock. The valve
incorporates a factory set, non-adjustable pressure reducer / strainer. The valve can be fitted in any orientation to suit
the installation, however, ensure that the valve is installed with the direction of flow arrows (stamped on the side of the
brass body) pointing towards the cylinder.
PRV WARNING:
IF THERE IS AN UPSTREAM CHECK VALVE OR FITTING WHICH MAY PREVENT BACKFLOW THEN HIGH PRESSURES
CAN BE EXPERIENCED DUE TO AMBIENT TEMPERATURES WHICH CAN CAUSE DAMAGE TO THE VALVES AND
FITTINGS
