User's Manual

Water expands by up to 4% when heated (See Fig. 1). This
means that the design of the water heater and the installation in
which it is used are critical. Conventional (vented) and unvented
systems allow for expansion in different ways.
With unvented systems, there are no cistern tanks or open
outlets to accommodate expansion. All systems above 15 litre,
and some systems of 15 litre or less, employ an expansion vessel
or an internal air-gap to accommodate expansion.
With larger systems (above 15 litre), expansion is
accommodated either by a separate expansion vessel or an
internal air-gap. Multipoint 75 and 100 litre units use an expansion
vessel which is supplied factory fitted within the casing. They are
supplied complete with all the necessary components and
controls to provide a safe and efficient method of providing
stor
ed mains pr
essur
e hot water.
Building Regulations
Dir
ect connection to the cold mains supply has been per
mitted in
the UK since 1987. All units above 15 litre must be installed to
meet the requirements of the Building Regulations. It is a legal
r
equir
ement that the local Building Contr
ol Of
ficer be notified of
any proposed installation of unvented water heating systems over
15 litre capacity. Products up to 500 litre and 45kW must be
appr
oved by a r
ecognised body such as the British Board of
Agrément (BBA) and BEAB and be fitted by an installer who has
successfully completed a recognised course in the installation of
unvented heating systems such as CITB.
Requir
ements call for an expansion space (internal or external),
safety devices to prevent the stored water exceeding 99°C, and
pipework to convey dischar
ged hot water safely away fr
om the
safety devices.
10 20 30 40 50 60 70 80 90 100
4
3
2
1
0
4
.34
TEMPERATURE RISE
O
C
EXPANSION %
1.2
FIG. 1
Blended water
to outlets
Pack U3 or U7
blending valve
Outlet taps
Hot outlet
Cold water in
Balanced
cold water
supply
Heater
Thermostatic blending valves
06
Accessory selection
Multipoint 75/100 ACCESSORIES
Pack U3 and U7 for use with all Multipoints;
PACK U3 TMV2
Connection
15mm compression.
Allows water to be safely stored above 60°C
P
recisely controls outlet water temperature
(range 35°C to 60°C)
Lockable contr
ol knob
Fail-safe shutdown
Incorporates check valves to pr
event cross contamination
Operating pressure 0.2 bar to 6.0 bar
P
ACK U7 TMV3
Connection
15mm compression.
Fully approved under the TMV3 scheme to the DO8
specification
Allows water to be safely stored above 60°C
P
recisely controls outlet water temperature
(range 38°C to 46°C)
Unique adjuster key to prevent unauthorised
temperature adjustment
Fail-safe shutdown
Incorporates check valves to prevent cross contamination
Operating pressure 0.2 bar to 5.0 bar
T
hermostatic blending valves
a
llow water to be stored at high temperatures and
blended with cold water to a preset outlet temperature. This provides over-temperature
protection, and is ideal for the control of Legionellae and the extension of
system capacities.
TMV Installation
Technical Support
Heatrae Sadia offers a dedicated Specifier Advice line to provide information and
advice on specification and installation. This is supported by a fully-trained national
sales team, all of whom are qualified to provide further guidance and support locally.