APR 2018
6
Hot Water Energy Storage
Unvented Cylinders
GB & NI
Installation & Maintenance Instructions for an unvented
hot water cylinder with external thermal expansion
COLD MAINS PIPEWORK
Run the cold mains through the building to the place where
the unvented cylinder is to be installed. Take care not to run
the cold pipe near hot water or heating pipework so that the
heat pick-up is minimised. Identify the cold water supply pipe
and fit an isolating valve (not supplied).
We recommend using a full bore 22mm quarter turn ball
valve, alternatively a 22mm stopcock can be used, however
this may reduce the flow rate.
Do not
use a “screwdriver
slot” or similar service valve.
For pre-plumbed units simply make the connection to the
inlet control set (Position A Page 12). For standard models
make the connection to the cold feed of the cylinder and
incorporate a drain valve. Position the drain valve no higher
than the cold inlet to ensure sufficient draining of the
cylinder when required. Position the inlet control just
above
the Temperature & Pressure Relief Valve (TPRV) mounted on
the side of the cylinder. This ensures that the cylinder does
not have to be drained down in order to service the inlet
control set. Ensure that the arrow points in the direction of
the water flow.
Select a suitable position for the expansion vessel. Mount
it to the wall using the bracket attached to the vessel. Use
suitable fittings capable of supporting full vessel weight (and
with appropriate consideration to wall material). Connect
the expansion vessel to the cold feed pipework between the
inlet control set and the cold inlet on the cylinder. Ensure
that the top of the vessel is accessible for servicing.
Connecting to the cylinder
All of the pipework connections on the cylinder are 22mm
compression and supplied complete with gland nuts and
olives, in the Accessory Kit box. Only connect 22mm
BS EN1057-R250 copper tube to these connections.
Cut the tube square using a rotary tube cutter and ensure no
sharp edges or burrs protrude. Slide both gland nut and olive
onto the tube and push tube fully home into the connection,
ensuring the tube end fully bottoms on the connection
recess. Smear the outer wall of the olive with plumbing paste
and tighten the gland nut in the prescribed manner. Upon
filling/commissioning, ensure all connections are completely
watertight, including immersion bosses and any pre-plumbed
pipework if applicable.
Note:
No control or isolation valve should be fitted between
the expansion relief valve and the storage cylinder. The relief
valve connections should not be used for any other purpose.
Expansion vessel (not to scale)
Turn to
test
Cold
Mains In
Balanced Cold
Connection
Outlet to Cylinder
Expansion
Relief to
Tundish
Expansion
Relief
Connection
INSTALLATION INSTRUCTIONS
