4
CYLINDER SUPPLY AND SAFETY DISCHARGE SCHEMATIC
GENERAL INSTALLATION AND COMMISSIONING
PLEASE NOTE - THE WATER CONNECTION BOSSES AND THE OLIVES & GLAND NUTS SUPPLIED AS
STANDARD ON THIS UK CYLINDERS INDIRECT ARE 3/4” BSP.
COLD MAINS PIPEWORK
The cold mains pipework should be a minimum of 22mm, through to the cylinder installation to ensure that
hot water flow requirements for taps and shower heads are met. Care should be taken to avoid
inefficiency and heat transfer where cold water pipes run adjacent to hot water or heating pipework.
Install an isolating valve (not supplied) to the cold mains pipework. A 22mm BS1010 stopcock or a
quarter turn full-bore lever valve should be used rather than a screwdriver slot or other similar valve.
Make the connection to the cold feed of the cylinder, incorporating a drain valve.
Position the inlet control set above the Temperature and Pressure Relief Valve (T&P) found on the side of the
cylinder. This ensures the cylinder does not need to be drained in order to service the inlet control. Ensure
the directional flow arrow on the inlet control follows the flow of water.
Mount the external expansion vessel in a suitable position to the wall using the provided bracket, and
connect the pipework to the expansion vessel connection provided on the cold water inlet set. There must
be no obstruction or flow restriction between the cylinder and the expansion vessel.
You must ensure that the cylinder does not fill to a pressure of greater than 3.0bar. If there are to be any
showers, bidets, or monobloc taps in the installation (or wherever mixing/blending water fittings are
installed) then a balanced cold supply is necessary, otherwise there is the danger of a mains fed cold service
pressure leaking into the controlled hot circuit. Such back pressure would be detrimental to the system and
could cause the unwarranted operation of discharge valves.
It is essential that the cold service be balanced throughout the property by taking the cold services from the
balanced cold connection on the inlet control set. Should this not be possible an independent 3.0bar inlet
Immersion Heater
T&P
Tundish
Hot Outlet
Drain Valve (not supplied)
via cold inlet
Balanced Cold
Connection
Non-return valve
Expansion Relief valve
Expansion
Vessel & Wall
Bracket
Pressure Reducing valve
Isolation valve (not supplied)
Cold
Mains
Cold Water Inlet Set
*Do not fit shut off valve between
cylinder & expansion valve
Secondary Return
(selected models
only)
Pump
Non-return
valve
Heating
Flow
Control Stat
Heating
Return
2-Port
