andrews STOR-SS300-8-S Manual

2 Issue 1 06/02/20
Andrews Water Heaters
Reproduction of any information in this publication by any
method is not permitted unless prior written approval has been
obtained from Andrews Water Heaters.
Andrews Water Heaters have been designed and manufactured
to comply with current international standards of safety. In the
interests of the health and safety of personnel and the continued
safe, reliable operation of the equipment, safe working practices
must be employed at all times. The attention of U users is
drawn to their responsibilities under the Health and Safety
Regulations 1993.
All installation and service on Andrews Water Heaters must be
carried out by properly qualified personnel and, therefore, no
liability can be accepted for any damage or malfunction caused
as a result of intervention by unauthorised personnel.
Andrews Water Heaters’ policy is one of continuous product
improvement and, therefore, the information in this manual,
whilst completely up to date at the time of publication, may be
subject to revision without prior notice.
Further information and assistance can be obtained from:
Customer support
onday - Thursday: 8am - 5pm
Friday: 8am - 4.30pm
Sales: 0345 070 1055
Technical: 0345 070 1057
Email: [email protected]
Website: www.andrewswaterheaters.co.uk
Twitter: @andrewsWH
Copyright Andrews Water Heaters 2020

Issue 1 06/02/20 3
Contents
Contents
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1 Introduction
1.1 General Information
1.2 Symbols Used
1.3 Liabilities
1.3.1 Manufacturers Liability
1.3.2 Installer’s Liability
1.3.3 Users Liability
2 Safety
2.1 General Safety Warnings
2.2 Recommendations
2.3 Specific Safety Instructions
3 Technical Specifications
3.1 Indirect Single and Twin Coil Connections & Technical Data
3.2 ErP Data
3.3 Dimensions and Connections
3.3.1 STOR-SS300-8-S
3.3.2 STOR-SS500-8-S
3.3.3 STOR-SS800/1000-8-S
3.3.4 STOR-SS300-8-T
3.3.5 STOR-SS500-8-T
3.3.6 STOR-SS800/1000-8-T
3.4 Electrical Diagram
4 Description of Product
4.1 General Description
4.2 Operation Principle
5 Before Installation
5.1 Installation Regulations
5.2 Installation Requirements
5.2.1 Water Supply
5.2.2 Outlet/Terminal Fittings (Taps, etc.)
5.2.3 Limitations
5.3 Choice of Location
6 Installation
6.1 General
6.2 Water Connections
6.2.1 Cold Water Control Pack
6.2.2 Primary Circuit Control
6.2.3 Secondary Circulation
6.2.4 Discharge
6.2.5 Worked Example of Discharge Pipe Sizing
6.3 Electrical Connections
6.4 Filling the Installation

4 Issue 1 06/02/20
Contents
Contents continued
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28
29
29
29
29
29
29
29
30
30
31
31
31
33
33
33
33
33
34
34
36
7 Commissioning
7.1 General
7.2 Checklist Before Commissioning
7.3 Commissioning Procedure
7.3.1 Indirect Units
7.3.2 Flow Performance
7.3.3 Temperature Controls
7.3.4 Operational Faults
8 aintenance
8.1 General
8.1.1 Maintenance Requirements
8.2 Standard Inspection & Maintenance Operations
8.2.1 Inspection
8.2.2 Safety Valve Operation
8.2.3 Strainer
8.2.4 Expansion Vessel Charge Pressure
8.2.5 Re-Commissioning
9 Troubleshooting
9.1 Fault Finding
9.1.1 Important
10 Decommissioning
10.1 Decommissioning Procedure
10.2 Environmental Information
10.3 WEEE Declaration
10.4 RoHs Declaration
11 Spare Parts
11.1 Baxi Genuine Parts List
Warranty

Issue 1 06/02/20 5
Introduction 1
Note
Signals important information.
1 Introduction
1.1 General Information
The following instructions are offered as a guide to the user and
installer.
The installation must be carried out by a competent plumbing
and electrical installer in accordance with Building Regulation
G3 (England and Wales), Technical Standard P3 (Scotland) or
Building Regulation P5 (Northern Ireland) and the Water Fitting
Regulations (England and Wales) or Water Byelaws (Scotland).
1.2 Symbols Used
In these instructions, various risk levels are employed to draw
the user’s attention to particular information. In doing so we wish
to safeguard the user, avoid hazards and guarantee the correct
operation of the appliance.
Danger
Risk of a dangerous situation causing serious physical
injury.
Warning
Risk of dangerous situation causing slight physical injury.
Caution
Risk of material damage.

6 Issue 1 06/02/20
1 Introduction
1.3 Liabilities
1.3.1 anufacturers liability
Our products are manufactured in compliance with the
requirements of the various applicable European regulations
and Directives.
This appliance complies with the requirements of the CE
marking directive.
In the interest of U customers, we are continuously
endeavouring to make improvements in product quality. All the
specifications stated in this document are therefore subject to
change without notice.
Our liability as the manufacturer may not be invoked in the
following cases:
• Failure to abide by the instructions on using the appliance.
• Faulty or insufficient maintenance of the appliance.
• Failure to abide by the instructions on installing the product.
1.3.2 Installer’s liability
The installer is responsible for the installation and the
commissioning of the appliance. The installer must respect the
following instructions:
• Read and follow the instructions given in the manuals
provided with the appliance.
• Carry out installation in compliance with the prevailing
legislation and standards.
• Perform the initial start up and carry out any checks
necessary.
• Complete the commissioning checklist.
• Explain the installation to the user.
• If maintenance is necessary, warn the user of the obligation
to check the appliance and maintain it in good working order.
• Give all the instruction manuals to the user.
1.3.3 Users liability
To guarantee optimum operation of the appliance, the user must
respect the following instructions:
• Read and follow the instructions given in the manuals
provided with the appliance.
• Call on qualified professionals to carry out installation and
initial start up.
• Get your fitter to explain your installation to you.
• Have your required checks and services done.
• eep the instruction manuals in good condition and close to
the appliance.
Note
This appliance can be used by children aged from 8
years and above and persons with reduced physical
sensory or mental capabilities or lack of experience and
knowledge if they have been given supervison or
instruction concerning use of the appliance in a safe way
and understand the hazards involved. Children shall not
play with the appliance. Cleaning and user maintenance
shall not be made by children without supervision.
Children must be supervised to ensure they do not play
with the appliance.

Issue 1 06/02/20 7
Safety 2
2 Safety
2.1 General Safety Warnings
2.2 Recommendations
2.3 Specific Safety Instructions
Danger
This cylinder is intended to be used as unvented and as
such becomes pressurised when in operation. The
combination of pressurisation and hot water could lead
to serious physical injury if the safety instructions in this
manual are not adhered to.
Warning
• Only competent persons received adequate training
having are permitted to work on the appliance and
the installation.
• Do Not tamper with any of the safety valves or
controls supplied with the cylinder.
• Before any work, switch off the mains supply to the
appliance.
• Do Not switch on if there is a possibility that the
water in the cylinder is frozen.
Warning
When handling the unit, take appropriate precautions
for the weight of the unit.
Caution
Annual maintenance is recommended by a competent
person.
See
Weights can be found in section 3.1 page 8.
Warning
• If water discharges from the temperature/pressure
relief valve on the cylinder shut down the heat
source. Do not turn off any water supply. Contact a
competent installer for unvented water heaters to
check the system.
• Do Not tamper with any of the safety valves fitted
to the system. If a fault is suspected contact a
competent installer.
• Do Not bypass the thermal cut-out(s) in any
circumstances.

8 Issue 1 06/02/20
3 Technical Specifications
300 500 800 1000 300 500 800 1000
Single Single Single Single Twin Twin Twin Twin
Coil surface area (bottom) m2 1.4 1.8 2.7 3.3 1.4 1.8 2.7 3.3
Coil surface area (top) m2 N/A N/A N/A N/A 1.1 1.3 1.3 1.3
Coil rating (bottom) kW 49 61 83 115 49 61 83 115
Coil rating (top) kW N/A N/A N/A N/A 40 45 45 45
Flow rate (bottom) m3/h 6 6 8 8 6 6 8 8
Flow rate (top) m3/h N/A N/A N/A N/A 6 6 6 6
Indirect heat time (mins) L/Mins 46 64 69 84 46 64 69 84
Pressure drop through bottom coil kPa 20 20 60 60 20 20 60 60
Pressure drop through top coil kPa N/A N/A N/A N/A 20 20 20 20
Heat loss (kWh in 24h) kWh 1.78 2.42 2.60 3.38 1.78 2.42 2.60 3.38
Storage capacity L 291 484 769 955 291 484 758 945
Weight full (kg) g 376 601 933 1144 384 610 933 1145
Weight empty (kg) g 85 117 164 189 93 126 175 200
Max design pressure Bar 8 8 8 8 8 8 8 8
Nominal operating pressure Bar 6 6 6 6 6 6 6 6
Expansion relief valve setting Bar 8 8 8 8 8 8 8 8
Temperature and pressure Bar/°C 10/95 10/95 10/95 10/95 10/95 10/95 10/95 10/95
relief valve setting
Maximum primary pressure (coil) Bar 25 25 25 25 25 25 25 25
Maximum working temperature °C 70 70 70 70 70 70 70 70
Coil odels(s) 300 500 800 1000 300 500 800 1000
Single Single Single Single Twin Twin Twin Twin
Energy efficiency class C C - - C C - -
Standing loss (kWh/24h) 1.78 2.42 2.60 3.38 1.78 2.42 2.60 3.38
Storage volume 291 484 769 955 291 484 758 945
3.2 ErP data
Standing heat-loss
Note
1. Indirect cylinders tested in conformance with BS EN 12897: 2016. Heat up time from cold through 50°C,
based on a flow temperature of 80°C +/- 2°C & normal volume.
Note
Testing is carried out to BS EN 12897: 2016
3 Technical Specifications
3.1 Technical data

Issue 1 06/02/20 9
Technical Specifications 3
3.3 Dimensions and Connections
Fig. 1
3.3.1 STOR-SS300-8-S
ø620
Section -A-B-
70
346
355
760
50
23
8
9
1
7
6
8
10
14
10
15
1685
1415
-B-
-A-
Side
inspection
detail
Connections
1 Cold water inlet/draining 1” Male AISI 316
2 D.H.W. outlet 1” Male AISI 316
3 Recirculation 1” Male AISI 316
6 Primary circuit inlet 1” Male AISI 316
7 Primary circuit outlet 1” Male AISI 316
8 Side connection 1-1/2” Male AISI 316
9 Valve P&T connection 3/4” Female AISI 316
10 Side gasket EPDM
11 Top gasket EPDM
12 Probe tube for sensor AISI 316
13 Recirculation pipe AISI 316
14 Valve P&T 3/4” 10 bar
15 Side stainless steel disk AISI 316
D.H.W. Tank
• Material: AISI 316 chemically
descaled and passivated
• Max. working pressure: 8 bar
• Max. working temperature:
70°C
• Volume: 291L
Heating coils
• Material: AISI 316
• Max. working pressure: 25 bar
• Max. working temperature:
90°C
• Heat exchange area: 1.4m2
• Volume: 10.4L
Thermally Insulated
• Polyurethane foam (C.F.C. free)
• Density 45 g/m3
Equipments
• White outer lining
• Top cover
• Control panel with thermometer
and regulating thermostat
Technical Characteristics
42°
9
14

10 Issue 1 06/02/20
3 Technical Specifications
Fig. 2
3.3.2 STOR-SS500-8-S
Connections
1 Cold water inlet/draining 1” Male AISI 316
2 D.H.W. outlet 1” Male AISI 316
3 Recirculation 1” Male AISI 316
6 Primary circuit inlet 1” Male AISI 316
7 Primary circuit outlet 1” Male AISI 316
8 Side connection 1-1/2” Male AISI 316
9 Valve P&T connection 1-1/4” Female AISI 316
10 Side gasket EPDM
11 Top gasket EPDM
12 Probe tube for sensor AISI 316
13 Recirculation pipe AISI 316
14 Valve P&T 1-1/4” 10 bar
15 Side stainless steel disk AISI 316
D.H.W. Tank
• Material: AISI 316 chemically
descaled and passivated
• Max. working pressure: 8 bar
• Max. working temperature:
70°C
• Volume: 484L
Heating coils
• Material: AISI 316
• Max. working pressure: 25 bar
• Max. working temperature:
90°C
• Heat exchange area: 1.8m2
• Volume: 13.8L
Thermally Insulated
• Polyurethane foam (C.F.C. free)
• Density 45 g/m3
Equipments
• White outer lining
• Top cover
• Control panel with thermometer
and regulating thermostat
Technical Characteristics
ø770
Section -A-B-
70
380
400
855
50
23
8
9
1
7
6
8
10
14
10
15
1690
1371
-B-
35°
-A-
Side
inspection
detail
9
14

Issue 1 06/02/20 11
Technical Specifications 3
Fig. 3
3.3.3 STOR-SS800/1000-8-S
Connections
1 Cold water inlet/draining 1-1/4” Male AISI 316
2 D.H.W. outlet 1-1/2” Male AISI 316
3 Recirculation 1-1/2” Male AISI 316
6 Primary circuit inlet 1” Male AISI 316
7 Primary circuit outlet 1” Male AISI 316
8 Side connection 1-1/2” Male AISI 316
9 Valve P&T connection 1-1/4” Female AISI 316
10 Side gasket EPDM
11 Top gasket EPDM
12 Probe tube for sensor AISI 316
14 Valve P&T 1-1/4” 10 bar
15 Side stainless steel disk AISI 316
D.H.W. Tank
• Material: AISI 316 chemically
descaled and passivated
• Max. working pressure: 8 bar
• Max. working temperature:
70°C
• Volume mod 800: 769L
• Volume mod 1000: 955L
Heating coils
• Material: AISI 316
• Max. working pressure: 25 bar
• Max. working temperature:
90°C
• Heat exchange area
Mod. 800: 2.7m2
Mod. 1000: 3.3m2
• Volume mod 800: 20.8L
• Volume mod 1000: 24.7L
Thermally Insulated
• Polyurethane foam (C.F.C. free)
• Density 45 g/m3
Equipments
• White outer lining
• Top cover
• Control panel with thermometer
and regulating thermostat
Technical Characteristics
ø950 ø790
Section -M-N-
282
100
50
9
1
7
A
B
EF
C
D
8
2
3
6
11
12
14
10
15
6,3,2
1,7,8,9,14
800
-N--M-
Side
inspection
detail
Manipulation eye bolt
provide with the tank
A B C D E F
STOR-SS800-8-S 1840 907 300 265 600 1472
STOR-SS1000-8-S 2250 1057 375 450 775 1882

12 Issue 1 06/02/20
3 Technical Specifications
Fig. 4
3.3.4 STOR-SS300-8-T
D.H.W. Tank
• Material: AISI 316 chemically
descaled and passivated
• Max. working pressure: 8 bar
• Max. working temperature:
70°C
• Volume: 291L
Heating coils
• Material: AISI 316
• Max. working pressure: 25 bar
• Max. working temperature:
90°C
• Heat exchange area:
1.4m2+ 1.1m2
• Volume: 10.4L + 7.8L
Thermally Insulated
• Polyurethane foam (C.F.C. free)
• Density 45 g/m3
Equipments
• White outer lining
• Top cover
• Control panel with thermometer
and regulating thermostat
Technical Characteristics
Connections
1 Cold water inlet/draining 1” Male AISI 316
2 D.H.W. outlet 1” Male AISI 316
3 Recirculation 1” Male AISI 316
4 Upper primary circuit inlet 1” Male AISI 316
5 Upper primary circuit outlet 1” Male AISI 316
6 Lower primary circuit inlet 1” Male AISI 316
7 Lower primary circuit outlet 1” Male AISI 316
8 Side connection 1-1/2” Male AISI 316
9 Valve P&T connection 3/4” Female AISI 316
10 Side gasket EPDM
11 Top gasket EPDM
12 Probe tube for sensor AISI 316
13 Recirculation pipe AISI 316
14 Valve P&T 3/4” 10 bar
15 Side stainless steel disk AISI 316
ø620
Section -A-B-
346
355
400
130
760
1415
1685
50
70
9
3 2
1
7
9
8
6
5
4
10
14
8
14
10
15
-A-
-B-
Side
inspection
detail
42°

Issue 1 06/02/20 13
Technical Specifications 3
Fig. 5
3.3.5 STOR-SS500-8-T
D.H.W. Tank
• Material: AISI 316 chemically
descaled and passivated
• Max. working pressure: 8 bar
• Max. working temperature:
70°C
• Volume: 484L
Heating coils
• Material: AISI 316
• Max. working pressure: 25 bar
• Max. working temperature:
90°C
• Heat exchange area:
1.8m2+ 1.3m2
• Volume: 13.8L + 9.5L
Thermally Insulated
• Polyurethane foam (C.F.C. free)
• Density 45 g/m3
Equipments
• White outer lining
• Top cover
• Control panel with thermometer
and regulating thermostat
Technical Characteristics
Connections
1 Cold water inlet/draining 1” Male AISI 316
2 D.H.W. outlet 1” Male AISI 316
3 Recirculation 1” Male AISI 316
4 Upper primary circuit inlet 1” Male AISI 316
5 Upper primary circuit outlet 1” Male AISI 316
6 Lower primary circuit inlet 1” Male AISI 316
7 Lower primary circuit outlet 1” Male AISI 316
8 Side connection 1-1/2” Male AISI 316
9 Valve P&T connection 1-1/4” Female AISI 316
10 Side gasket EPDM
11 Top gasket EPDM
12 Probe tube for sensor AISI 316
13 Recirculation pipe AISI 316
14 Valve P&T 1-1/4” 10 bar
15 Side stainless steel disk AISI 316
ø770
Section -A-B-
380
400
350
140
855
1371
1690
50
70
9
3 2
1
7
9
8
6
5
4
10
14
8
14
10
15
-A-
-B-
Side
inspection
detail
35°

14 Issue 1 06/02/20
3 Technical Specifications
Fig. 6
3.3.6 STOR-SS800/1000-8-T
D.H.W. Tank
• Material: AISI 316 chemically
descaled and passivated
• Max. working pressure: 8 bar
• Max. working temperature:
70°C
• Volume mod 800: 758L
• Volume mod 1000: 945L
Heating coils
• Material: AISI 316
• Max. working pressure: 25 bar
• Max. working temperature:
90°C
• Heat exchange area
mod 800: 2.7m2+ 1.3m2
mod 1000: 3.3m2+ 1.3m2
• Volume mod 800: 20.8L + 9.5L
Volume mod 1000: 24.7L + 9.5L
Thermally Insulated
• Polyurethane foam (C.F.C. free)
• Density 45 g/m3
Equipments
• White outer lining
• Top cover
• Control panel with thermometer
and regulating thermostat
Technical Characteristics
Connections
1 Cold water inlet/draining 1-1/4” Male AISI 316
2 D.H.W. outlet 1-1/2” Male AISI 316
3 Recirculation 1-1/2” Male AISI 316
4 Upper primary circuit inlet 1” Male AISI 316
5 Upper primary circuit outlet 1” Male AISI 316
6 Lower primary circuit inlet 1” Male AISI 316
7 Lower primary circuit outlet 1” Male AISI 316
8 Side connection 1-1/2” Male AISI 316
9 Valve P&T connection 1-1/4” Female AISI 316
10 Side gasket EPDM
11 Top gasket EPDM
12 Probe tube for sensor AISI 316
13 Recirculation pipe AISI 316
14 Valve P&T 1-1/4” 10 bar
15 Side stainless steel disk AISI 316
A B C D E F G
STOR-SS800-8-T 1840 907 300 265 600 1472 1052
STOR-SS1000-8-T 2250 1057 375 450 775 1882 1237
ø950 ø790
Section -M-N- Partial section for -P-
282
350
100
50
9
1
7
A
B
EF
G
C
D
8
5
4
2
3
6
11
12
14
10
15
6,3,2
4,5
1,7,8,9,14
800
-N-
-P-
-M-
Side
inspection
detail
Manipulation eye bolt
provide with the tank

Issue 1 06/02/20 15
Technical Specifications 3
3.4 Electrical Diagram
Dual safety and temperature control thermostat, manual
reset.
The control panel is equipped with a dual safety and
temperature control thermostat.
If the thermostat safety device is triggered it has to be manually
reset.
To do this the thermostat must be dismantled as indicated
below.
1. Disconnect the power supply to the tank to ensure there is
no power supply to the control panel and prevent any risk
of electric shocks.
2. Dismantle the control panel by unscrewing the four corner
screws that fix it to the tank.
3. Remove the protective front control panel.
4. Remove the temperature setting dial by pressing outwards.
5. Unscrew the two screws on the part left uncovered by the
dial. When mounting it again make sure that the position
of the screws is correct.
6. Turn the thermostat round from the back part of the control
panel without the need to disconnect any wires. On the
back part of the thermostat there is a compartment marked
with an ‘S’. Press the tab inside the compartment with a
fine object to reset the thermostat.
7. Reverse the above steps to reassemble the thermostat.
Warning
The high limit stat must always operate the zone valve
in case of over temperature.
Fig. 7
The control panel /TD has a thermometer and a regulating
and safety thermostat.
- Pilot lights
Te° - Thermometer
TL° - Regulating thermostat
and safety thermostat
❄/☼ - Summer / Winter switch
K - External contactor
(Leave in winter position as the
summer position will disable the
heating)
❄/☼
Te°
TL°
ELN34567891011ABCDEFO/ITL*ReAB23A1B2A5A3B6B4TB425LN230V50HzPowerSupplyDHWPrimaryPump(1ampMax)DHWPrimaryZoneValve
Fig. 8

16 Issue 1 06/02/20
4 Description of Product
This product is a purpose designed unvented water heater. The
unit has a stainless steel inner vessel, which ensures an
excellent standard of corrosion resistance. The outer casing is
a combination of resilient thermoplastic mouldings and soft
jacket. All products are insulated with CFC free polyurethane
foam to give good heat loss protection.
This unit is certified and intended to be used in an unvented
system. The unvented system kit offered by Baxi Heating must
be purchased at the same time. If this kit isn’t purchased, it
could invalidate the warranty of the cylinder.
4 Description of Product
4.1 General Description
The unvented cylinder is used to heat and store hot water for
use in commercial applications.
To provide pressure to the tap or shower an unvented unit uses
the incoming mains water pressure. To do this the cylinder is
sealed and not vented. However, when the volume of water is
heated it expands and without any room for expansion could
cause the cylinder to rupture and fail. To allow expansion of this
heated water it is important that an expansion vessel is used.
This vessel is pressurised and gives the heated water room to
expand.
4.2 Operation Principle

Issue 1 06/02/20 17
Before Installation 5
5 Before Installation
5.1 Installation Regulations
5.2 Installation Requirements
Warning
Installation of the appliance must be carried out by a
qualified engineer in accordance with prevailing and
national regulations as listed below.
• Building Regulations
• The Building Standards (Scotland)
• The Building Regulations (Northern Ireland)
• I.E.E Electrical Regs
• U Water Regulations
5.2.1 Water supply
In an unvented system the pressure and flowrate is directly
related to the incoming water supply. For this reason it is
recommended that the maximum water demand is assessed
and the water supply checked to ensure this demand can be
satisfactorily met.
• We suggest the minimum supply requirements should be
0.15MPa (1.5 bar) pressure and 100 litres per minute flow
rate to ensure adequate discharge of hot water through the
T&P valve in the event of overheating.
• A 28mm cold water supply is recommended, however, if a
smaller supply exists, which provides sufficient flow, this
may be used (although more flow noise may be
experienced).
• The higher the available pressure and flow rate the
better the system performance.
• See Technical Data Table for cylinder operating pressures.
5.2.2 Outlet/terminal fittings (taps, etc.)
• The cylinder can be used with most types of terminal
fittings.
• Outlets situated higher than the cylinder 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.
• All fittings, pipework and connections must have a rated
pressure of at least 8 bar at 80°C.
5.2.3 Limitations
The cylinder should not be used in association with any of the
following:
• Solid fuel heat sources or any other heat source in which the
energy input is not under effective thermostatic control,
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.

18 Issue 1 06/02/20
5 Before Installation
5.3 Choice of Location
• Steam heating plants unless additional and appropriate
safety devices are installed.
• Situations where maintenance is likely to be neglected or
safety devices tampered with.
• Water supplies that have either inadequate pressure 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.
• In areas where the water supply contains chloride levels that
exceed 250mg/l.
The cylinder must be vertically floor mounted. Although location
is not critical, the following points should be considered:
• The cylinder 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 pipe work should be insulated.
• 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 must be available for the
servicing and maintenance of the system. Where these
controls are installed against a wall a minimum distance of
250mm must be left.
• Ensure that the floor area for the cylinder is level and
capable of permanently supporting the weight when full of
water.
See
Weights can be found in section 3.1 page 8.
Min250mmMin250mmMin600mm
Fig. 9

Issue 1 06/02/20 19
Installation 6
After reading the previous sections in this booklet and choosing
a good location for the unit please install, paying attention to the
following hydraulic, electrical and commissioning sections.
6.1.1 Heat Source selection
• The Heat Source should have a control thermostat and non
self-resetting thermal cut-out and be compatible with
unvented storage water heaters.
• The Primary Circuit from the Heat Source can be a sealed
system or open vented type - maximum primary pressure 25
bar.
• The Heat Source cannot be vented through the cylinder.
6 Installation
6.1 General
• All pipe fittings are made via BSP pipe connections directly
to the unit.
• A stopcock or servicing valve should be incorporated into the
cold water supply to enable the cylinder and its associated
controls to be isolated and serviced (not supplied).
• The expansion vessel must be connected between the cold
water combination valve and the cylinder.
• The location of the expansion vessel should allow access to
recharge the pressure as and when necessary.
• A suitable draining tap should be installed in the cold water
supply to the cylinder between the expansion valve and the
heater at as low a level as possible.
• It is recommended that the outlet point of the drain pipework
be at least 1 metre below the level of the heater (this can be
achieved by attaching a hose to the drain tap outlet spigot).
6.2 Water Connections
Warning
• Under no circumstances should the factory fitted
temperature/pressure relief valve be removed other
than by a competent person. To do so will invalidate
any guarantee or claim.
• The cold water combination valve is part of the
unvented kit and MUST be installed in accordance
with G3 Building regulations.
• No control or safety valves should be tampered with
or used for any other purpose.
• The discharge pipe should not be blocked or used
for any other purpose.
• The tundish should not be located adjacent to any
electrical components.
See
Refer to the installation schematic Fig. 10, page 20 for
details on the pipework layout.
Specific details for the discharge pipework layout is also
provided in Fig. 13 on page 25.

20 Issue 1 06/02/20
6 Installation
T&P relief
valve
Primary return
Primary flow
Secondary
return
To hot outlets
Mains water
supply
Expansion
vessel
Balanced cold
water connection
Pressure reducing
valve
Pressure relief
valve
Drain cock Tundish Discharge pipe
Inlet
6.2.1 Unvented system kit
• The cold water control pack can be connected anywhere on
the cold water cylinder supply prior to the expansion vessel.
• The control pack incorporates the strainer, check valve, core
unit and expansion relief valve.
• The pressure settings are adjustable and should be set
between 1 & 8 bar.
• The valve can be fitted in any orientation to suit the
installation as long as the valve is installed with the direction
of flow arrows pointing in the correct direction.
• The expansion relief valve should be installed with the
discharge pipework in either the horizontal position or facing
downwards.
• No other valves should be placed between the cold water
combination valve and the cylinder.
• The blank plastic plugs in the body of the pressure relief
valve 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).
Typical installation schematic (not to scale)
Caution
• The expansion vessel pressure must be set in
accordance with the inlet pressure set on the
pressure reducing valve.
• 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 any warranty.
Fig. 10