Heatrae Sadia ELECTROMAX Release note

Installation & Servicing Instructions 1
INSTALLATION &
SERVICING INSTRUCTIONS
ELECTROMAX
Combined Electric Flow Boiler
and Direct Unvented Water Heater
Please read and understand these instructions before starting work
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commissioning

2 Installation & Servicing Instructions
SECTION PAGE
1.0 Introduction
1.1 Important Notes 3
1.2 Basic Operation of the
Electromax 3
1.3 Storage, Unpacking and
Handling 4
1.4 Contents Check List 4
2.0 Technical Data 5
3.0 General Requirements
3.1 Location of the Electromax 9
3.2 Water Supply 9
3.3 Pipework, Fittings and Outlet/
Terminal Fittings 10
3.4 Treatment of the Primary
(Central Heating) Circulating
System 10
3.5 Sealed Primary Systems 11
4.0 Installation - General
4.1 Positioning the Electromax 12
4.2 Removal of Panels 12
4.3 Cable Entry Positions 13
4.4 Programmable Room
Thermostat 13
5.0 Installation - Plumbing
5.1 Pipe Fittings 14
5.2 Cold Water Combination
Valve 14
5.3 Secondary Expansion Vessel 14
5.4 Balanced Hot Water Supplies 15
5.5 Outlet Pipework 15
5.6 Secondary Circulation 15
5.7 Discharge Pipework 15
5.8 Primary (Central Heating)
Pipework 18
6.0 Installation - Electrical
6.1 Important Notes 19
6.2 Off Peak and 24 Hour
Electrical Supply 19
6.3 Boiler Connection (45 Amp) 21
6.4 Programmable Room
Thermostat 21
Contents
SECTION PAGE
7.0 Commissioning
7.1 Filling the Electromax
Cylinder 22
7.2 Filling the Sealed System
Primary Circuit 23
7.3 Check the Operation of the
Safety Valves 23
7.4 Set the Programmable Room
Thermostat 24
7.5 Preliminary Electrical Checks 24
7.6 Check Operation of the
Electric Boiler 24
7.7 Setting the Automatic By-pass
Valve 25
7.8 Check Operation of the
Immersion Heaters 26
7.9 Demonstration to User 26
8.0 Maintenance
8.1 Maintenance Requirements 27
8.2 Check Cylinder Water Supply 27
8.3 Descaling Immersion Heaters 27
8.4 Operation of Cylinder Safety
Valves 28
8.5 Operation of Primary System
Safety Valve 28
8.6 Primary System Expansion
Vessel Charge Pressure 28
8.7 Electrical Checks 29
9.0 Fault Finding and Servicing
9.1 Fault Finding 30
9.2 Replacement Parts 35
9.3 Servicing 37
10.0 Guarantee 43
11.0 Spares Stockists 44

Installation & Servicing Instructions 3
1.0 Introduction
1.1 Important Notes
The Electromax must be installed in
accordance with the manufacturer’s
instructions and all relevant regulations
in force at the time of installation.
This appliance is not intended for use
by persons (including children) with
reduced physical, sensory or mental
capabilities, or lack of knowledge
and experience, unless they have
been given supervision or instruction
concerning the use of the appliance by
a person responsible for their safety.
The Electromax Domestic Hot Water
Cylinder is of the UNVENTED type.
Its installation is subject to Building
Regulation G3 (England and Wales),
Technical Standard P3 (Scotland) or
Building Regulation P5 (Northern Ireland).
Installation must be carried out by a
competent person.
The Electromax should be installed and
maintained by a competent person. Please
read and understand these instructions
before installing the Electromax. Following
installation and commissioning the
operation of the Electromax, the central
heating system and associated controls
should be explained to the customer and
these instructions left with them for future
reference.
The Electromax electric heating boiler must
be installed into a sealed (pressurized)
primary system. Following installation of
the primary system the system should be
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an inhibitor added.
The Electromax Domestic Hot Water
cylinder is directly heated by means of
electric immersion heaters. The electric
central heating boiler although housed
in the same casing operates completely
independently to the cylinder. It is strongly
recommended that the water heating is
done by means of an Off-Peak electrical
supply.
The use of an Off-Peak tariff that provides
at least three off peak electricity periods,
such as Economy 10, is recommended.
Where possible the central heating
“on” periods should be programmed
to coincide with the off peak electricity
periods available during the day. This
will ensure maximum economy of the
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Guide” for information on the off peak
periods available from various electricity
providers.
The Electromax does not contain any
substances harmful to health; it does not
contain any asbestos. Small quantities
of adhesives and sealants used in the
manufacture of the product are cured and
present no known hazards.
1.2 Basic operation of the Electromax
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boiler and direct electrically heated unvented
domestic water heating cylinder.
The domestic hot water is preferentially
heated by an Off Peak electricity supply via an
immersion heater that is specially designed to
heat virtually the complete cylinder capacity.
A “Boost” immersion heater is also provided
to allow a smaller quantity of water to be
heated should the stored hot water be fully
used during the day. The cylinder is factory
insulated with a low heat loss expanded
polyurethane foam.

4 Installation & Servicing Instructions
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a sealed (pressurized) primary system. It
is suitable for conventional radiator based
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sealed system functional and safety controls,
including the circulating pump and primary
expansion vessel. The boiler automatically
responds to lower central heating loads by
reducing (modulating) the boiler output which
saves wasteful on-off cycling. For summer
use the boiler can be switched off on the
Electromax control panel, however a “pump
exercise” facility will energise the circulating
pump for a brief period every day to prevent
pump seizure through long periods without
use.
Time and temperature control of the central
heating is by means of a Programmable
Room Thermostat which is supplied loose
with the Electromax for remote siting in a
suitable, convenient position.
The necessary cold water mains supply
controls are supplied in a kit for installation
on site in a suitable, convenient position.
7KHVHPXVWEH¿WWHGWRFRPSO\ZLWK%XLOGLQJ
Regulation G3 and Water Fittings Regulations
or Byelaws.
1.3 Storage, Unpacking and Handling
The Electromax is delivered in protective
expanded polystyrene packaging with
reinforced corner posts. The assembly is
shrunk wrapped in heavy duty polythene. The
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boxed and attached to the main assembly
by 2 polypropylene bands. The assembly
must be stored upright, under cover in dry
conditions.
Units must not be stacked. The packaging
must be removed prior to installation.
Note the weight of the product and the
handling instructions applied to the packaging.
If using a handling device, eg. A sack barrow,
to manually move the Electromax, trucking
must be done from the rear to avoid damage
to the outer panels.
The Electromax should be lifted and handled
by two persons. Handholds are provided in
the top rear panel, in both side panels and
underneath the Electromax assembly to
aid lifting. Stooping should be avoided and
protective clothing worn when necessary.
The packaging is recyclable and should be
disposed of in accordance with environmental
guidelines.
1.4 Contents check list
Within the Electromax packaging the following
components are supplied. Please check that
all parts are available before commencing
installation.
x Electromax unit
x Cold Water Combination Valve
comprising Pressure Reducing Valve,
Strainer, Check Valve and Expansion
Valve
x Unvented system Expansion Vessel
(18 litre, pre-charged to 3.5 bar)
x Wall mounting bracket for Expansion
Vessel
x Programmable Room Thermostat
x Immersion heater key spanner
x Hose connection adaptor for primary
system drain valve
x Set of Cable Entry Glands and blanking
plugs (3 x 20mm, 1 x 25.4mm)
x Installation Manual
x User Instructions
x Fitting template

Installation & Servicing Instructions 5
2.0 Technical Data
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h42/hWk'orhtdetaehytitnauQ)sertil(
Thro'45deg C Thro'50deg C 45deg C in60mins
180 180 200 57 litres 1.95
OffP eak heater 3kW
Timeto heat(mins)
CylinderPerform ance
Specification /feature
ElectricBoiler& P rimaryCirc u it
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8.3kW at230 V
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Electricalsupplyfrequency 50 H z
V042taspmA5.73gnitary
lppuslacirtcelE
.Am03gnitarpirT.spmA54gnitarDCR
Internalfuse rating (P um p supply) 2 A m ps
delaeSepytmetsysyramirP
Primarysystem operating pressure(min) 100kP a (1bar)
Primarysystem pressurerel
iefvalve s e tting 300kP a (3bar)
Prim arysystem E xpansion V essel 12 litre.P re-charged to 100kP a (1bar)
PrimaryFlow Tem perature R adiatorM odel A djustablefrom 65 to 80 deg C
PrimaryFlow Tem perature U nderfloor M odel A djustablefrom 30 to60degC
Adjustable 10 to 50kP a (0.1-0.5bar)differentialpressure.dettifdeilppuSev
lavssapybcitamotuA
Primarycirculating pum p S upplied fitted. Grundfos U P S 15-50
.dettifdeilppuStnevriacitamotuA
.dettifdeilppuSpoolgnillifyrarop
meT
DHW cylinder
OffP eak immersion heaterinput 3kW at240 V
2.8kW at230 V
Boostimmersion heater input 3kW at240 V
2.8kW at230 V
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evlaVnoitanibmoCretaWdloChtiwlargetnI.)rab5.3(aPk05
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noisnapxE
)rab5.3(aPk053o
tdegrahc-erP.ertil81lesseVnoisnapxEWHD
Tem perature/PressureReliefV alve 90 deg C / 1000kP a (10 bar)
Com bined thermostat and therm alcut-out Thermostatadjustable10to 70 deg C .R e-settablec
ut-out80 deg C
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wlargetnIevlaVkcehC
evlaVnoitanibmoCretaWdloChtiwlargetnIreniartS
.orezlaitnetopnoitelpedenozO.enahteru
ylopdednapxeCFCH/CFCnoitalusnI
GlobalW arming potential3.1
Com plete unit
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P ackaged dimensionsH xW xD (mm) Electrom ax unit: 1566 x 600 x 650
Installation K it:320x315x610

6 Installation & Servicing Instructions
Diagram 1 Dimensions
600
550
1476
50
Min.
clearance
either
side
300
Minimum clearance
over Top Panel for
access
TOP
FRONTLEFT HAND
SIDE
Side Panel Lifting
Points (Mirrored in
Right Hand Side
Panel)
Lifting Points In Base
Lifting Points
In Upper Rear
Panel
Tundish
Viewing
Window

Installation & Servicing Instructions 7
Diagram 2 Key Components
User Interface Panel
Electrical Connection
Terminal Blocks
Primary System Pressure
Relief Valve
Temperature / Pressure
Relief Valve
Tundish
Automatic Bypass
Valve
Discharge Pipe
Primary Flow
Isolating Valve
Primary Return
Isolating Valve
Primary System
Drain Point
Filling Loop
Isolating Valve
(Primary Side)
Cold Water Inlet
Connection
Hot Water Outlet
Connection
Filling Loop
Isolating Valve
Off Peak Immersion
Heater
Filling Loop
Electric Boiler
Domestic Hot
Water Cylinder
(Insulated)
Boost Immersion
Heater
Boiler Electronic Control
(Under Cover)
Fascia Panel
Top Panel
Primary System
Expansion Vessel
Primary Circulating
Pump
Automatic Air Vent
Electric Control Circuitry
(Mounted Behind Fascia)
Primary System
Expansion Vessel
Connection
Primary System
Expansion Vessel
Air Valve
Panel Mounted Fuses 3 amp

8 Installation & Servicing Instructions
SPEED
SETTING
SPEED
R.P.M.
INPUT
POWER (W)
FULL LOAD
CURRENT (A)
LOCKED ROTOR
CURRENT (A)
lll 2300 50 0.23 0.30
ll 2100 45 0.20 0.25
l 1700 35 0.16 0.20
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 Q (m /h)
3
1.0
2.0
3.0
4.0
5.0
3
2
1
H (m)
Diagram 3 Pump Characteristics
Diagram 4 Automatic Bypass Valve Characteristics
0
0.2
0.4
0.6
0.8
1
1.2
0 300 600 900 1200 1500 1800 2100 2400 2700 3000
V (l/h)
Differential Pressure (bar)

Installation & Servicing Instructions 9
3.0 General Requirements
3.1 Location of the Electromax
The Electromax must not be sited outside or
in any location where it could be exposed to
the weather. It must be installed in a dry and
frost free environment.
The Electromax must be vertically mounted
RQDÀDWOHYHOVXUIDFHFDSDEOHRIVXSSRUWLQJ
the “full” weight of the unit. When full the unit
weighs a total of 256kg.
The location chosen must allow the discharge
pipe from the unvented cylinder safety
valves to be correctly installed. Domestic hot
water pipe runs should be kept as short as
SRVVLEOH IRU PD[LPXP HFRQRP\ 6XI¿FLHQW
access must be allowed around the unit to
allow removal of the front and top panels for
servicing and maintenance of the system.
Refer to Diagram 1, page 6 for details of
recommended minimum clearances.
An installation template is supplied with the
unit to aid in location and layout of pipework
connections.
3.2 Water supply
Bear in mind that the mains water supply to
the property will be supplying both the hot
and cold water requirements simultaneously.
It is recommended that the maximum
water demand be assessed and the water
supply be checked to ensure this demand
can be satisfactorily met.
NOTE: A high mains water pressure will
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Wherever possible the mains water supply
pipe should be in 22mm OD (copper) or
25mm OD (Blue MDPE). The minimum mains
water supply requirements should be 1.0 bar
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YDOXHVRXWOHWÀRZUDWHVPD\EHSRRULIVHYHUDO
outlets are used simultaneously, the higher
WKHDYDLODEOHSUHVVXUHDQGÀRZUDWHWKHEHWWHU
the system performance will be.
The Electromax unvented cylinder has
an operating pressure of 3.5 bar which is
controlled by the Cold Water Combination
Valve. The Cold Water Combination Valve
can be connected to a maximum mains
supply pressure of 16 bar. The water supply
must be of wholesome water quality (Fluid
&DWHJRU\DVGH¿QHGE\WKH:DWHU6XSSO\
Regulations 1999).
In some areas of the UK the water supply
may have a high level of natural hardness.
Whilst this is not detrimental to the quality
of the water, in water heating systems the
calcium carbonate which causes the water’s
“hardness” can precipitate onto hot surfaces
and in time adversely affect hot water
performance. If the temporary hardness of
the cold water mains supply exceeds 200mg/l
(check with your Water Supply Company) it
is recommended that some form of water
treatment is considered. Any device selected
must be suitable for use in unvented water
heating systems and not unduly affect the
ÀRZUDWHFDSDFLW\WRWKH(OHFWURPD[F\OLQGHU
consult the manufacturer of the device for
details.

10 Installation & Servicing Instructions
3.3 Pipework, Fittings and Outlet / Terminal
Fittings
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systems and have a rated operating
pressure of at least 6 bar. Where plastic
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pressure must be achievable at outlet
temperatures that can be expected within
the hot water distribution pipework. If in
doubt, consult the manufacturer of the
¿WWLQJVVHOHFWHG
The Electromax unvented cylinder can
be used in conjunction with most types of
WHUPLQDO¿WWLQJV,WLVDGYDQWDJHRXVLQPDQ\
mixer showers or taps to have balanced
pressure hot and cold water supplies, in
these instances the balanced cold water
supply should be teed off the supply to the
Electromax immediately after the Cold Water
Combination Valve (see diagram 5).
Branches to cold outlets where drinking
water may be drawn should be taken
directly from the main supply before the
Cold Water Combination Valve to avoid
the possibility of warm expanded water
being drawn from cold taps.
3.4 Treatment of the Primary (Central
Heating) Circulating System
Primary water circulating systems will be
subject to corrosion unless an appropriate
water treatment is applied. Without treatment
WKHHI¿FLHQF\RIWKHV\VWHPZLOOEHUHGXFHG
over time as corrosion sludge accumulates
within the system, risking damage to the pump
and valves, system noise and circulation
problems.
Electromax Housing
Unvented System
Primary System
Unvented Cylinder
Temperature /
Pressure Relief
Valve
Discharge Pipe
Cylinder Drain Expansion Valve
Discharge
Cold Water
Mains Supply
Expansion
Vessel
Cold Balanced
Draw Off (to
Mixer Outlets)Cold Draw Off
(to Drinking
Water Outlets)
Cold Water
Combination
Valve
Tundish
Isolating
Valve
Diagram 5 System Schematic - DHW Cylinder

Installation & Servicing Instructions 11
For optimum performance after installation
the Electromax boiler and its associated
FHQWUDO KHDWLQJ V\VWHP PXVW EH ÀXVKHG LQ
accordance with the guidelines given in BS
7593:1992 “Treatment of water in domestic
hot water central heating systems”. This must
involve the use of a proprietary cleanser, such
as GE Betz Sentinel X300 or X400, Fernox
³6XSHUÀRF´RU6DODPDQGHU6\VWHP&OHDQVHU
Follow the manufacturer’s instructions to
ensure correct cleansing of the system.
For long term protection against corrosion
DQGVFDOHDIWHUÀXVKLQJWKHV\VWHPVKRXOG
be dosed with an inhibitor such as GE Betz
Sentinel X100, Fernox MB-1 or Copal, or
Salamander System Inhibitor in accordance
with the guidelines given in BS 7593:1992.
)DLOXUHWRÀXVKDQGDGGLQKLELWRUWRWKH
system will invalidate the appliance
warranty.
3.5 Sealed Primary Systems
The Electromax boiler must be installed in a
sealed primary system. All necessary primary
V\VWHP FRQWUROV DUH VXSSOLHG ¿WWHG WR WKH
Electromax. The sealed system expansion
vessel fitted has a capacity of 12 litres
which, as a general guide, will be suitable
for a heating system of up to 107 litres. If
in doubt the total primary system volume
must be calculated to determine if additional
expansion volume is required.
The Electromax initial primary system cold
¿OOSUHVVXUHLVEDU7KHH[SDQVLRQYHVVHO
size = 0.11 x the total system volume. The
boiler and pipework within the Electromax
hold approx. 2 litres of water, therefore
additional system expansion volume will
only be necessary for systems that exceed
107 litres.
The Electromax boiler incorporates an
DXWRPDWLFDLUYHQWDWLWVKLJKHVWSRLQW¿WWHG
to the pump housing, see Diagram 6). If any
primary pipework is routed above the level
of the Electromax additional air vents must
EH¿WWHGWRWKHKLJKHVWSRLQWVRIWKHÀRZDQG
return pipes and at any point where air is
likely to collect.
$Q DXWRPDWLF E\SDVV YDOYH LV ¿WWHG WR WKH
Electromax to allow thermostatic radiator
YDOYHVWREH¿WWHGWRWKHV\VWHP
Electromax Housing
Unvented System
Primary System
Electric Boiler
Filling Loop
Primary System
Drain Valve
Primary System
Pressure Relief
Valve
Primary
Flow
Primary
Return
Isolating
Valves - to Radiators
or Undefloor System
Automatic
Bypass Valve
Primary System
Expansion Vessel
Circulating
Pump
Automatic
Air Vent
Diagram 6 System Schematic - Primary Circuit

12 Installation & Servicing Instructions
4.0 Installation - General
4.1 Positioning the Electromax
Decide where the Electromax is to be
installed. Reference must be made to the
dimensions of the unit and the minimum
access space requirements (see Diagram 1,
page 6). Consideration must also be taken
of the routing of the pipework to the unit,
provision of the discharge pipe and siting
of any external controls such as the Cold
Water Combination Valve and secondary
system Expansion Vessel. Pipework can
be connected from below the unit or from
the left and right hand sides. Knock-outs
are provided in the side panels for side
connections. A template is provided to aid
in positioning the unit and determining the
pipework entry locations.
If using side entry pipework the following
connections are made to the Electromax
(when viewed from front of unit see Diagram
2, page 7):
Left hand side
3ULPDU\ÀRZSULPDU\UHWXUQGLVFKDUJHSLSH
Right hand side
Cold water inlet supply, hot outlet supply
Note the weight of the product (see Technical
Specifications) and adopt safe lifting
techniques. A two man lift is recommended.
Hand holds are provided in the left and right
hand side panels, the rear and underside.
If the front panels are removed prior to
SRVLWLRQLQJ LQ LWV ¿QDO LQVWDOODWLRQ SRVLWLRQ
DO NOT lift using the exposed pipework
assembly.
4.2 Removal of Panels
Refer to Diagram 7. For installation and
commissioning the front and top panels must
be removed. The lower front panel must be
removed before the upper front panel.
The lower front panel (Panel A on Diagram
7) is secured by spring clips and is removed
E\SXOOLQJIRUZDUGXVLQJWKH¿QJHUUHFHVVHV
either side of the panel. Once removed, the
two M5 screws securing the lower edge of
the upper front panel must be removed. The
upper front panel (Panel B on Diagram 7)
must then be removed by pulling forward
to disengage it from the remaining spring
clips.
The top panel (Panel C on Diagram 7) is
secured by two screws and spring clips. To
remove, unscrew the two securing screws on
the top panel and then pull upwards using the
¿QJHUUHFHVVHVHLWKHUVLGHRIWKHSDQHO
A
B
C
'LDJUDP5HPRYDORI3DQHOV

Installation & Servicing Instructions 13
4.3 Cable Entry Positions
The electrical supply cables can be routed to
enter the unit from the left or right hand side
(see Diagram 8). There are four cable entry
holes in each upper side panel; one 25mm
diameter and three 20mm diameter. The
accessory kit contains a set of cable glands
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VKRXOGEH¿WWHGLQWRWKHFDEOHHQWU\KROHVRQ
the side selected for cable entry and secured
in place using the lock nuts supplied. The
remaining four cable entry holes not used
should be blanked off using the appropriate
blanking plugs supplied.
The cable glands must be used to secure the
HOHFWULFDOVXSSO\FDEOHVZKHQ¿WWHG)DLOXUH
to do so can result in the cables straining
internal electrical connections and possible
electrical failure as a result. Failure due to
inadequate cable securing will not be covered
by the warranty.
4.4 Programmable Room Thermostat
The Electromax is supplied with a Danfoss
TP5000 Programmable Room Thermostat.
This is supplied in the accessory kit supplied
with your unit. Follow the installation
instructions provided with the Programmable
Room Thermostat for correct siting and
mounting of the unit. If the radiators are to
EH¿WWHGZLWK7KHUPRVWDWLF5DGLDWRU9DOYHV
(TRV’s) the room where the Programmable
Room Thermostat is located must not have
a TRV fitted in compliance with Building
Regulation Part L.
Right hand cable
entry holes shown.
Left hand holes
are mirrored in left
hand panel.
20mm
25mm
Top
Panel
Diagram 8 Cable Entry Positions
Front
Panel
Diagram Programmable Room Thermostat

14 Installation & Servicing Instructions
5.0 Installation - Plumbing
3LSH¿WWLQJV
Pipe connections to the Electromax must be
PDGHXVLQJPPFRPSUHVVLRQW\SH¿WWLQJV
Solder connections directly to the unit must
not be made as the heat may damage the
insulation materials used. Damage caused
E\ KHDW DSSOLHG WR VROGHU ¿WWLQJV LQ FORVH
proximity to the unit will not be covered by
the warranty. Solder connections may be
used elsewhere in the system away from the
(OHFWURPD[XQLW8VHZDWHUVROXEOHÀX[IRU
PDNLQJVROGHUHGMRLQWVDQGHQVXUHDQ\ÀX[
residue is removed following installation.
5.2 Cold Water Combination Valve
The Cold Water Combination Valve can be
connected anywhere on the cold water mains
supply prior to the Electromax unit, however
it must be possible to connect the secondary
system Expansion Vessel between this
valve and the cold inlet connection of the
unit. Whilst it is often more convenient to
do so, there is no requirement to site the
valve close to the unit, it can be located at
a point remote from the unit if this is more
convenient. However, ensure the discharge
from the Expansion Valve (see Diagram 10)
can be correctly installed. The Expansion
Valve connection must not be used for any
other purpose.
The Cold Water Combination Valve is installed
as a complete one-piece unit. The valve
incorporates an Isolating Valve, a Pressure
Reducer, a Strainer, an Expansion Valve
and a single Check Valve. The valve can be
¿WWHGLQDQ\RULHQWDWLRQWRVXLWWKHLQVWDOODWLRQ
however, ensure the valve is installed with
WKHGLUHFWLRQRIÀRZDUURZVVWDPSHGRQWKH
side of the brass body) pointing towards the
Electromax unit.
EXPANSION VALVE
COLD MAINS
CONNECTION
(22mm)
EXPANSION VALVE
OUTLET (15mm)
OUTLET
CONNECTION
(22mm)
PRESSURE
REDUCING
VALVE
HOUSING
PRESSURE
REDUCING
VALVE
CARTRIDGE (3.5 bar)
5.3 Secondary Expansion Vessel
The Secondary (DHW) Expansion Vessel is
VXSSOLHGLQWKHDFFHVVRU\NLWDQGPXVWEH¿WWHG
to the cold water supply to the Electromax
to accommodate any water expansion that
results from heating the water inside the
F\OLQGHU7KH([SDQVLRQ9HVVHOPXVWEH¿WWHG
between the Cold Water Combination Valve
and the cold inlet of the Electromax cylinder
(see Diagram 5, page 10).
The Expansion Vessel must be adequately
supported, a wall mounting bracket is
supplied for this purpose. The location of the
Expansion Vessel should allow access for
maintenance. This will entail access to the
air valve on top of the unit to check and, if
necessary, re-charge the vessel pre-charge
pressure. The vessel pre-charge pressure
is 3.5 bar.
Diagram 10 Cold Water Combination Valve

Installation & Servicing Instructions 15
5.4 Balanced Cold Water Supplies
It is advantageous in many mixer showers
or taps to have balanced pressure hot and
cold water supplies, in these instances the
balanced cold water supply should be teed
off the supply to the Electromax immediately
after the Cold Water Combination Valve (see
diagram 5, page 10).
Branches to cold outlets where drinking
water may be drawn should be taken
directly from the main supply before the
Cold Water Combination Valve to avoid
the possibility of warm expanded water
being drawn from cold taps.
5.5 Outlet Pipework
The pipework from the Electromax to the
KRW RXWOHW ¿WWLQJV VKRXOG EH LQ PP SLSH
with short runs of 15mm pipe to showers
and basins. Small bore pipe can be used to
suit some taps, but runs should be kept as
short as possible. Pipe sizes may vary due
to system design.
5.6 Secondary Circulation
Secondary circulation is not recommended
for the Electromax as it is intended for
Off-Peak electrical operation. During other
periods the electricity supply is interrupted
to the immersion heaters so no reheating
will take place. Circulating the stored water
would gradually cool it to an unacceptable
temperature.
'LVFKDUJH3LSHZRUN
It is a requirement of Building Regulations
that any discharge from an unvented system
should be visible and safely conveyed away
from the system without danger to persons in
or about the building where it is installed. The
GLVFKDUJHSLSHVKRXOGEH¿WWHGLQDFFRUGDQFH
with the requirements and guidance notes of
Building Regulations. Building Regulation G3
Requirements and Guidance section 3.9 are
reproduced in the following sections.
Information Sheet No.33 available from
the British Board of Agrement gives further
advice on discharge pipe installation. For
discharge pipe arrangements not covered
by G3 Guidance or BBA Info sheet No. 33
advice should be sought from either your
local Building Control Officer or Heatrae
6DGLD7KHGLVFKDUJHSLSHZRUNVXSSOLHG¿WWHG
to the Electromax will convey any discharge
from the unvented cylinder Temperature
and Pressure Relief Valve and the sealed
system Pressure Relief Valve. A discharge
pipe will also be required from the Expansion
9DOYH¿WWHGWRWKH&ROG:DWHU&RPELQDWLRQ
Valve. Where practical this can be teed into
the discharge pipe from the Electromax. It
is recommended that an additional tundish
LV ¿WWHG LQWR WKLV GLVFKDUJH SLSH WR JLYH DQ
early indication of operation of the Expansion
Valve.
In some instances it may be possible to
discharge into an internal waste system and
soil stack. To do this a self sealing waste
YDOYHPXVWEH¿WWHGLQWRWKHGLVFKDUJHSLSH
after the tundish to prevent foul odours or
back-pressurisation from the waste system
entering the building via the tundish. In these
systems it is essential that the tundish is
¿WWHGLQDYLVLEOHSRVLWLRQDVWKH¿QDOSRLQW
of discharge will not be visible. Consult
the manufacturer’s recommendations with
UHVSHFWWRWKHFRUUHFW¿WWLQJRULHQWDWLRQDQG
waste and soil stack materials selection. It
will also be necessary to get dispensation
IURP \RXU ORFDO %XLOGLQJ &RQWURO 2I¿FHU WR
discharge in this manner. Discharges from
an unvented system can be up to 95oC for
several minutes, ensure any waste or soil
pipe connected to the discharge can
safely accept these conditions.
G3 REQUIREMENT
“…there shall be precautions…to ensure that
the hot water discharged from safety devices
is safely conveyed to where it is visible but
will not cause danger to persons in or about
the building.”

16 Installation & Servicing Instructions
Water may drip from the discharge pipe of
the pressure-relief device and that this pipe
must be left open to the atmosphere.
The pressure-relief device is to be operated
regularly to remove lime deposits and to
verify that it is not blocked.
The discharge pipe connected to the
pressure relief device is to be installed in a
continuously downward direction and in a
frost free environment
**8,'$1&(6(&7,21
The discharge pipe (D1) (see Diagram
11, page 17) from the vessel up to and
including the tundish is generally supplied
by the manufacturer of the hot water storage
system. Where otherwise, the installation
should include the discharge pipe(s) (D1)
from the safety device(s). In either case
the tundish should be vertical, located in
the same space as the unvented hot water
VWRUDJH V\VWHP DQG EH ¿WWHG DV FORVH DV
possible and within 500mm of the safety
device e.g. the temperature relief valve.
The discharge pipe (D2) from the tundish
should terminate in a safe place where there
is no risk to persons in the vicinity of the
discharge, preferably be of metal and:
a. be at least one pipe size larger than the
nominal outlet size of the safety device unless
its total equivalent hydraulic resistance
exceeds that of a straight pipe 9m long
i.e. discharge pipes between 9m and 18m
equivalent resistance length should be two
pipe sizes larger, and so on. Bends must
EHWDNHQLQWRDFFRXQWLQFDOFXODWLQJWKHÀRZ
resistance. Refer to Diagram 11, Table 1 and
the worked example.
An alternative approach for sizing discharge
pipes would be to follow BS6700:1987
6SHFL¿FDWLRQIRUGHVLJQLQVWDOODWLRQWHVWLQJ
DQGPDLQWHQDQFHRIVHUYLFHVVXSSO\LQJZDWHU
IRU GRPHVWLF XVH ZLWKLQ EXLOGLQJV DQG WKHLU
FDUWLODJHVAppendix E, section E2 and Table
21.
b. have a vertical section of pipe at least
300mm long below the tundish before any
elbows or bends in the pipework.
c. be installed with a continuous fall.
d. have discharges visible at both the tundish
DQG¿QDOSRLQWRIGLVFKDUJHbut where this
LVQRWSRVVLEOHRULVSUDFWLFDOO\GLI¿FXOWWKHUH
should be clear visibility at one or other of
these locations.
Examples of acceptable discharge
arrangements are:
L LGHDOO\EHORZD¿[HGJUDWLQJDQGDERYH
the water seal in a trapped gully.
ii. Downward discharges at low level; i.e.
up to 100mm above external surfaces such
as car parks, hard standings, grassed areas
etc. are acceptable providing that where
children may play or otherwise come into
contact with discharges a wire cage or similar
guard is positioned to prevent contact, whilst
maintaining visibility.
iii. Discharges at high level; e.g. into
a metal hopper and metal down pipe with
the end of the discharge pipe clearly visible
(tundish visible or not) or onto a roof capable
of withstanding high temperature discharges
of water and 3m from any plastics guttering
system that would collect such discharges
(tundish visible).
iv. Where a single pipe serves a number
of discharges, such as in blocks of flats,
the number served should be limited to not
more than 6 systems so that any installation
discharging can be traced reasonably easily.
The single common discharge pipe should
be at least one pipe size larger than the
largest individual discharge pipe (D2) to be
connected. If unvented hot water storage
systems are installed where discharges from
safety devices may not be apparent i.e. in
GZHOOLQJVRFFXSLHGE\EOLQGLQ¿UPRUGLVDEOHG
people, consideration should be given to
the installation of an electronically operated
device to warn when discharge takes place.
Note: The discharge will consist of scalding
ZDWHUDQGVWHDP$VSKDOWURR¿QJIHOWDQGQRQ
metallic rainwater goods may be damaged by
such discharges.

Installation & Servicing Instructions 17
Worked example of discharge pipe
sizing
The example below is for a G1/2 temperature
relief valve with a discharge pipe (D2) having
4 No. elbows and length of 7m from the
tundish to the point of discharge.
From Table 1:
Maximum resistance allowed for a straight
length of 22mm copper discharge pipe
(D2) from a G1/2 temperature relief valve
is 9.0m.
Subtract the resistance allowed for 4 No.
22mm elbows at 0.8m each = 3.2m
Therefore the permitted length equates to:
5.8m
5.8m is less than the actual length of 7m
therefore calculate the next largest size.
Maximum resistance allowed for a straight
length of 28mm pipe (D2) from a G1/2
temperature relief valve equates to 18m.
Subtract the resistance of 4 No. 28mm
elbows at 1.0m each = 4.0m
Therefore the maximum permitted length
equates to 14.0m
As the actual length is 7m, a 28mm (D2)
copper pipe will be satisfactory.
Table 1 Sizing of Copper Discharge
Pipes (D2) for Common T&P Relief Valve
Sizes
Valve outlet size Minimum size of
discharge pipe D1
Minimum size of
discharge pipe D2
from tundish
Maximum
resistance
allowed,
expressed as a
length of straight
pipe (I.e. no
elbows or bends)
Resistance
created by each
elbow or bend
G1/2 15mm
22mm
28mm
35mm
up to 9m
up to 18m
up to 27m
0.8m
1.0m
1.4m
G3/4 22mm
28mm
35mm
42mm
up to 9m
up to 18m
up to 27m
1.0m
1.4m
1.7m
G1 28mm
35mm
42mm
54mm
up to 9m
up to 18m
up to 27m
1.4m
1.7m
2.3m
Fixed grating
Discharge below
fixed grating
(Building Regulation
G3 section 3.9d gives
alternative points
of discharge)
Trapped
gully
Discharge pipe (D2) from tundish,
with continuous fall. See Building
Regulation G3 section 3.9d i-iv,
Table 4 and worked example
300mm
minimum
500mm maximum
Metal discharge pipe (D1) from
Temperature relief valve to tundish
Tundish
Safety device
(e.g. Temperature
relief valve)
Diagram 11
Schematic Discharge
Pipe Arrangement

18 Installation & Servicing Instructions
5.8 Primary (Central Heating) Pipework
&RQQHFWLRQVWRWKH(OHFWURPD[SULPDU\ÀRZ
and return must be in 22mm o/dia. pipe.
,VRODWLQJYDOYHVDUH¿WWHGWRWKH(OHFWURPD[
XQLWRQWKHSULPDU\ÀRZDQGUHWXUQFRQQHFWLRQV
to enable the Electromax boiler to be isolated
from the primary circuit for maintenance and
servicing. Connections to the isolating valves
are 22mm compression.
Conventional radiator based central heating
design considerations should be made
in selecting the radiators and circulating
pipework sizes. The maximum output from
the Electromax boiler is 9kW, ensure the
radiator load does not exceed this. NOTE:
The Electromax boiler is dedicated to the
space heating only, the domestic hot water
is heated by separate immersion heaters,
so there is no requirement to allow a hot
water loading factor in designing the primary
system.
8VHZDWHUVROXEOHÀX[IRUPDNLQJVROGHUHG
MRLQWVDQGHQVXUHDQ\ÀX[UHVLGXHLVUHPRYHG
following installation.
A filling loop is provided within the
Electromax casing to fill the primary
circuit directly from the cold water supply.
When the system is full and correctly
SUHVVXUL]HGWKHÀH[LEOHKRVHRIWKH¿OOLQJ
loop should be disconnected from the
primary circuit.
Primary Flow
Isolating Valve
Primary Return
Isolating Valve
Filling Loop
Isolating Valve
(Primary Side)
Filling Loop
Isolating Valve
(Cold Water Side)
Cold Water
Inlet Connection
Hot Water
Outlet
Connection
Filling Loop
Flexible
Connection
6KRZQ¿WWHG
IRU¿OOLQJ
Diagram 12
Primary Connections

Installation & Servicing Instructions 19
6.0 Installation - Electrical
6.1 Important Notes
All wiring must be carried out in accordance
with the current IEE Wiring Regulations.
The Electromax electrical installation must
be carried out by a competent person in
accordance with any relevant regulations
in force at the time of installation and the
requirements of these instructions to ensure
correct operation.
The main incoming electrical supply to the
SURSHUW\PXVWEHRIVXI¿FLHQWFXUUHQWUDWLQJ
and voltage for the Electromax and any other
electrical requirements for the property.
7KH FRQVXPHU XQLW PXVW EH ¿WWHG ZLWK D
double pole RCD with a trip sensitivity of
30mA capable of breaking the full load
current to BS EN 61008:1994.
A correctly rated MCB must be used in
the supply to the Electromax boiler and
immersion heaters. The MCB to the boiler
must be rated at 45A. The MCB to each
immersion heater must be rated at 16A. It
PD\ EH QHFHVVDU\ WR ¿W D EODQNLQJ SODWH
between the 45A MCB and other MCB’s in the
consumer unit to provide ventilation, check
with the MCB manufacturer.
Each circuit must incorporate an isolating
switch which must have a minimum contact
separation of at least 3mm in all poles.
3 amp protection has been provided for the
thermostat ‘L’ and the pump ‘L’. The fuses
are located in the control assembly.
6.2 Off-Peak and 24 hour Electrical
Supply
To obtain optimum performance and lowest
running costs from your Electromax unit it
should be connected to an Off-Peak electrical
supply. The “Economy 10” tariff, which is
available from most major electricity suppliers,
is recommended. Table 2 shows the suppliers
that offer “Economy 10” and the times that “off
peak” electricity is supplied. Other Off-Peak
tariffs may be suitable, consult the Heatrae
6DGLD6SHFL¿FDWLRQ7HDPRU\RXUHOHFWULFLW\
supplier for further advice.
With an Off-Peak electrical supply there will
be two sets of electrical outputs from the
consumer unit or two separate consumer
units. One will supply the circuits that have a
dedicated off peak use (such as night storage
heaters or off peak water heater), the other
will provide a 24 hour supply to circuits in
use throughout the day (such as lighting,
sockets, etc.).
ECONOMY 10 PROVIDERS
Electricity Supplier Off-Peak Times GMT or Clock
Midlands midnight - 5.00am 1.00 - 4.00pm 8.00 - 10.00pm GMT
Norweb midnight - 5.00am 1.00 - 4.00pm 8.00 - 10.00pm GMT
Southern midnight - 5.00am 1.00 - 4.00pm 8.00 - 10.00pm GMT
South Wales midnight - 5.00am 1.00 - 4.00pm 8.00 - 10.00pm GMT
South Western midnight - 5.00am 1.00 - 4.00pm 8.00 - 10.00pm GMT
Yorkshire midnight - 5.00am 1.00 - 4.00pm 8.00 - 10.00pm GMT
Scottish Hydro 4.30 - 7.30am 1.00 - 4.00pm 8.30 - 12.30pm Clock
Manweb 4.30 - 7.30am 1.00 - 4.00pm 8.30 - 12.30pm Clock
Table 2 Economy 10 Providers

20 Installation & Servicing Instructions
Pum p Fuse (3 A m p) Thermostat‘L’Fuse (3 Am p)
Off Peak supply connection
A suitable electrical connection must be taken
from the Off Peak supply to the Electromax
terminal block. The supply cable should
be 1.5mm2cross sectional area 3 core
HOFR sheathed cable and must be routed
into the Electromax via one of the 20mm
FDEOH JODQGV SUHYLRXVO\ ¿WWHG VHH VHFWLRQ
3.3, page 10). The Live (Brown) conductor
should be connected to the termination
marked “OFF PEAK SUPPLY L”; the Neutral
(Blue) conductor should be connected to the
termination marked “OFF PEAK NEUTRAL
N”; the Earth (Green/Yellow) conductor
should be connected to one of the terminations
marked “EARTH CONNECTIONS “. See
section 6.1, page 19 for MCB and isolation
requirements.
24 Hour supply connection (NB NOT Boiler
connection)
A suitable electrical connection must be taken
from the 24 Hour supply to the Electromax
terminal block. The supply cable should
be 1.5mm2cross sectional area 3 core
HOFR sheathed cable and must be routed
into the Electromax via one of the 20mm
FDEOH JODQGV SUHYLRXVO\ ¿WWHG VHH VHFWLRQ
3.3, page 10). The Live (Brown) conductor
should be connected to the termination
marked “24 HOUR SUPPLY L”; the Neutral
(Blue) conductor should be connected to the
termination marked “ 24 HOUR NEUTRAL
N”; the Earth (Green/Yellow) conductor should
be connected to one of the terminations
marked “EARTH CONNECTIONS “. See
section 6.1, page 19 for MCB and isolation
requirements.
Diagram 13 Electrical Supply Connection Block