3
2.0 GENERAL REQUIREMENTS
2.1 COMPONENTS SUPPLIED
1. Heatstore HSU unvented water heater incorporat-
ing immersion heater(s) and thermal controls
2. Factory fitted Temperature/Pressure Relief Valve
3. Cold Water Combination Valve.
4. Expansion Vessel and mounting bracket.
5. Tundish.
6. Motorised Valve (Indirect models only).
7. Compression nuts and olives
8. Immersion heater key spanner
2.2 SITING THE UNIT
The Heatstore HSU unvented water heater must be
installed vertically. Although location is not critical,
the following points should be considered:
•
The Heatstore HSU should be sited to ensure
minimum dead leg distances, particularly to the point
of most frequent use.
•
Avoid siting where extreme cold temperatures will
be experienced. All exposed pipework should be in-
sulated.
•
The discharge pipework from the safety valves
must have minimum fall of 1:200 from the unit and
terminate in a safe and visible position.
•
Access to associated controls and immersion
heaters should be possible to allow for periodic
servicing and maintenance.
•
Ensure that the base chosen for the Heatstore
HSU is level and capable of permanently supporting
the weight when full of water (see Table 2).
2.3 WATER SUPPLY
Bear in mind that the mains water supply to the prop-
erty will be supplying both the hot and cold water re-
quirements simultaneously. It is recommended that the
maximum water demand is assessed and the water
supply checked to ensure this demand can be satisfac-
torily met.
NOTE
:
A high mains water pressure will not always
guarantee high flow rates.
Wherever possible the mains supply pipe should be
22mm. We suggest the minimum supply requirements
should be 1.5 bar pressure and 20 litres per minute
flowrate. However, at these values outlet flow rate may
be poor if several outlets are used simultaneously.
The higher the available pressure and flow rate the
better the system performance.
The Heatstore HSU has an operating pressure of 3.5
bar that is controlled by the Cold Water Combination
Valve. The Cold Water Combination Valve can be con-
nected to a maximum mains pressure of 16 bar.
2.4 OUTLET/TERMINAL FITTINGS (TAPS, ETC.)
The Heatstore HSU can be used with most types of
terminal fittings. It is advantageous in many mixer show-
ers to have balanced hot and cold water supplies. In
these instances a balanced pressure cold water con-
nection should be placed between the Cold Water
Combination Valve and the Heatstore HSU water
heater. Outlets situated higher than the Heatstore HSU
will give outlet pressures lower than that at the heater,
a 10m height difference will result in a 1 bar pressure
reduction at the outlet.
2.5 LIMITATIONS
The Heatstore HSU unvented water heater should not
be used in association with any of the following:
•
Solid fuel boilers or any other boiler in which the
energy input is not under effective thermostatic con-
trol unless additional and appropriate safety measures
are installed.
•
Ascending spray type bidets or any other class 1
back syphonage risk requiring that a type A air gap be
employed.
•
Steam heating plants unless additional and appro-
priate safety devices are installed.
•
Situations where maintenance is likely to be ne-
glected or safety devices tampered with.
•
Water supplies that have either inadequate pres-
sure or where the supply may be intermittent.
•
Situations where it is not possible to safely pipe
away any discharge from the safety valves.
•
In areas where the water consistently contains a
high proportion of solids, e.g. suspended matter that
could block the strainer, unless adequate filtration can
be ensured.
Table 3: Standing heat losses
Table 2: Unit weights
Based on an ambient air temperature of 20
o
C and a stored
water temperature of 65
o
C
Type
Model
reference
Nominal
capacity
(litres)
Weight of
unit full
(kg)
DIRECT
HSUDC100
100
124
HSUDC120
120
146
HSUDC150
150
179
HSUDC170
170
201
HSUDC210
210
252
HSUDC250
250
295
HSUDC300
300
355
INDIRECT HSUIC100
100
125
HSUIC120
120
147
HSUIC150
150
181
HSUIC170
170
204
HSUIC210
210
257
HSUIC250
250
301
HSUIC300
300
360
Nominal
capacity
per day
per year
(litres)
(kWh/24h)
(kWh/365d)
100
1.14
416.1
120
1.47
536.6
150
1.70
620.5
170
1.92
700.8
210
2.30
839.5
250
2.45
894.3
300
2.72
992.8
Standing Heat Loss
