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
Please leave this leaflet with the user following installation and
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 Cold Water Supplies 15
5.5 Outlet Pipework 15
5.6 Secondary Circulation 15
5.7 Discharge Pipework 15
5.8 Primary (Central Heating)
Pipework 19
6.0 Installation - Electrical
6.1 Important Notes 20
6.2 Off Peak and 24 Hour
Electrical Supply 20
6.3 Boiler Connection 22
6.4 Programmable Room
Thermostat 22
Contents
SECTION PAGE
7.0 Commissioning
7.1 Filling the Electromax
Cylinder 23
7.2 Filling the Sealed System
Primary Circuit 24
7.3 Check the Operation of the
Safety Valves 24
7.4 Set the Programmable Room
Thermostat 25
7.5 Preliminary Electrical Checks 25
7.6 Check Operation of the
Electric Boiler 25
7.7 Setting the Automatic By-pass
Valve 26
7.8 Check Operation of the
Immersion Heaters 27
7.9 Demonstration to User 27
8.0 Maintenance
8.1 Maintenance Requirements 28
8.2 Check Cylinder Water Supply 28
8.3 Descaling Immersion Heaters 28
8.4 Operation of Cylinder Safety
Valves 29
8.5 Operation of Primary System
Safety Valve 29
8.6 Primary System Expansion
Vessel Charge Pressure 29
8.7 Electrical Checks 30
9.0 Fault Finding and Servicing
9.1 Fault Finding 31
9.2 Replacement Parts 35
9.3 Servicing 37
10.0 Guarantee 43
11.0 Spares Stockists 44

Installation & Servicing Instructions 3
1.1 Important Notes
TheElectromaxmustbeinstalledinaccordance
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 (pressurised)
primary system. Following installation of the
primary system the system should be flushed
in accordance with BS 7593 and 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 system. Refer to Table 2, Page 20 “Tariff
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
The Electromax is an integrated electric flow
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.
The electric flow boiler must be installed
into a sealed (pressurised) primary system.
It is suitable for conventional radiator based
central heating systems & underfloor heating
systems when using underfloor controls and
is supplied fitted with all necessary primary
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
1.0 Introduction

4 Installation & Servicing Instructions
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. These must be
fitted to comply with Building 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
Electromax unvented fitting kit is supplied
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 (Page 5)
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.
• Electromax unit
• Cold water combination valve comprising
pressure reducing valve, strainer, check
valve and expansion valve
• Unvented system expansion vessel (18
litre, pre-charged to 3.5 bar)
• Wall mounting bracket for expansion
vessel
• Programmable room thermostat
• Immersion heater key spanner
• Hose connection adaptor for primary
system drain valve
• Set of cable entry glands and blanking
plugs (3 x 20mm, 1 x 25.4mm)
• Installation manual
• User instructions
• Fitting template

Installation & Servicing Instructions 5
2.0 Technical Data
ssoLtaeHWk3retaehtsooByticapaC
h42/hWk'orhtdetaehytitnauQ)sertil(
Thro' 45deg C Thro' 50deg C 45deg C in 60 mins
180 180 200 57 litres 1.95
Off Peak heater 3kW
Time to heat (mins)
Cylinder Performanc
e
Specification / feature
Ele ctric Boile r & Primary Circuit
9kW at 240 V or 6kW at 240 V)xam(tupnIlacirtcelE
V042ot022egatlovylppuslacirtcelE
Electrical supply frequency 50 Hz
V042taspmA5.73gnitarylppuslacirtcelE
.Am03gnitarpirT.spmA54gnitarDCR
Internal fuse rating (pu mp supply) 2 Amps
delaeSepytmetsysyramirP
Primary system operating pressure (min) 100kPa (1 bar)
Primary system pressure relief valve setting 300kPa (3 bar)
Primary system expansion vessel 12 litre. Pre-charged to 100kPa (1 bar)
Primary flow temperature radiator model Adjustable from 65 to 80 deg C
Primary flow temperature underfloor model Adjustable from 30 to 60 deg C
Adjustable 10 to 50kPa (0.1-0.5bar) differential pressure .dettifdeilppuSevlavssapybcitamotuA
Primary circulating pump Supplied fitted. Grundfos UPS 15-50
.dettifdeilppuStnevriacitamotuA
.dettifdeilppuSpoolgnillifyraropmeT
DHW cylinder
Off Peak immersion heater input 3kW at 240 V
2.8kW at 230 V
Boost immersion heater input 3kW at 240 V
2.8kW at 230 V
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)rab5.3(aPk053otdegrahc-erP.ertil81lessevnoisnapxeWHD
Temperature/Pressure relief valve 90 deg C / 1000kPa (10 bar)
Combined thermostat and thermal cut-out Thermostat adjustable 10 to 70 deg C. Re-settable cut-out 85 deg C
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.orezlaitnetopnoitelpedenozO.enahteruylopdednapxeCFCH/CFCnoitalusnI
Global warming potential 3.1
Com ple te unit
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Packaged dimensions H x W x D (mm) Electromax unit:1566 x 600 x 650
Installation kit : 320 x 315 x 610
8.3kW at 230 V or 5.5kW at 230 V

6 Installation & Servicing Instructions
600
550
1476
50
Min.
clearance
either
side
300
Minimum clearance
over Top Panel for
access
TOP
FRONT
LEFT 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
Diagram 1 Dimensions

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
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 2300500.230.30
ll 2100450.200.25
l1700350.160.20
0
0.20.40.60.81.01.21.4 1.61.82.02.22.42.62.83.0Q(m/h)
3
1.0
2.0
3.0
4.0
5.0
3
2
1
H (m)
Diagram 4 Automatic Bypass Valve Characteristics
0
0.2
0.4
0.6
0.8
1
1.2
0300 600900 1200 1500 1800 2100 2400 2700 3000
V (l/h)
Differential Pressure (bar)
Diagram 3 Pump Characteristics
Diagram 4 Automatic Bypass Valve Characteristics

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
on a flat, level surface capable of supporting
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 possible
for maximum economy. Sufficient 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 not
always guarantee high flow rates.
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
and 20 litres per minute flowrate. At these
values outlet flowrates may be poor if several
outlets are used simultaneously, the higher the
available pressure and flowrate the better the
system performance will be.
The Electromax unvented cylinder has an
operatingpressureof3.5 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 Category 1 as defined by the
Water Supply 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 flow rate capacity to the
Electromax cylinder, consult the manufacturer
of the device for details.
For optimum performance after installation the
Electromax boiler and its associated central
heating system must be flushed in 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 “Superfloc”
or Salamander system cleanser. Follow the
manufacturer’s instructions to ensure correct
cleansing of the system.
For long term protection against corrosion
and scale, after flushing, the system should
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.

10 Installation & Servicing Instructions
Failure to flush and add inhibitor to the system
will invalidate the appliance warranty.
3.3 Pipework, Fittings and Outlet / Terminal
Fittings
NOTE: All pipework, fittings and terminal
fittings must be compatible with unvented
systems and have a rated operating pressure
of at least 6 bar. Where plastic pipe / fittings
are being used the rated 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 fittings selected.
The Electromax unvented cylinder can be used
in conjunction with most types of terminal
fittings. 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.
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
the efficiency of the system will be reduced
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 DrainExpansion 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
Diagram 5 System Schematic - DHW Cylinder

Installation & Servicing Instructions 11
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
3.5 Sealed Primary Systems
The Electromax boiler must be installed in a
sealed primary system. All necessary primary
system controls are supplied fitted to the
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 fill
pressure is 1.0 bar. The expansion vessel 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
automatic air vent at its highest point (fitted
to the pump housing, see diagram 6, page
11). If any primary pipework is routed above
the level of the Electromax additional air vents
must be fitted to the highest points of the flow
and return pipes and at any point where air is
likely to collect.
An automatic bypass valve is fitted to the
Electromax to allow thermostatic radiator
valves to be fitted to the system.
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
Primary flow, primary return, discharge pipe
Right hand side
Cold water inlet supply, hot outlet supply.
Note the weight of the product (see Technical
ata, page 5) 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 positioning in its
final installation position DO NOT lift using
the exposed pipework assembly.
4.2 Removal of Panels
Refer to diagram 7, page 12. 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, page 12) is secured by spring clips and is
removed by pulling forward using the finger
recesses 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, page 12)
is secured by two screws and spring clips. To
remove, unscrew the two securing screws on
the top panel and then pull upwards from the
front edge.
A
B
C
Diagram 7 Removal of Panels

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, page 13). 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 and snap fit blanking plugs. The cable
glands should be fitted into the cable entry
holes on 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
electrical supply cables when fitted. Failure 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 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 be fitted with thermostatic
radiator valves (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 9 Programmable Room Thermostat

14 Installation & Servicing Instructions
5.0 Installation - Plumbing
5.1 Pipe fittings
Pipe connections to the Electromax must be
made using 22mm compression type fittings.
Solder connections directly to the unit must
not be made as the heat may damage the
insulation materials used. Damage caused by
heat applied to solder fittings in close proximity
to the unit will not be covered by the warranty.
Solder connections may be used elsewhere
in the system away from the Electromax unit.
Use water soluble flux for making soldered
joints and ensure any flux 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, page 14) 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 a pressure reducer, a strainer,
an expansion valve and a single check valve.
The valve can be fitted in any orientation to
suit the installation, however, ensure the valve
is installed with the direction of flow arrows
(stamped on the side of the brass body)
pointing towards the Electromax unit.
5.3 Secondary Expansion Vessel
The Secondary (DHW) expansion vessel is
supplied in the accessory kit and must be fitted
to the cold water supply to the Electromax to
accommodate any water expansion that results
from heating the water inside the cylinder. The
expansion vessel must be fitted 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
Expansion valve
Cold mains
connection
(22mm)
Expansion valve
outlet (15mm)
Outlet connection
(22mm)
Pressure reducing
valve cartridge
(3.5bar)

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 hot
outlet fittings should be in 22mm pipe 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.
5.7 Discharge Pipework
It is a requirement of Building Regulation G3
that any discharge from an unvented system is
conveyed to where it is visible, but will not cause
danger to persons in or about the building.
The tundish and discharge pipes should be
fitted in accordance with the requirements and
guidance notes of Building Regulation G3. The
G3 Requirements and Guidance section 3.50 -
3.63 are reproduced in the following sections of
this manual. For discharge pipe arrangements
not covered by G3 Guidance advice should
be sought from your local Building Control
Officer. Any discharge pipe connected to the
pressure relief devices (expansion valve and
temperature/pressure relief valve) must be
installed in a continuously downward direction
and in a frost free environment.
Water may drip from the discharge pipe of
the pressure relief device. 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.
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.”
Notes:
Discharge pipe-work D2 can now be a plastic
pipe but only pipes that have been tested to a
minimum 110°C must be used.
Discharge pipe D2 can now be plumbed into
the soil stack but only soil stacks that can
handle temperatures of 99°C or greater should
be used.
The following extract is taken from the latest
G3 Regulations
Discharge pipe D1
3.50 Safety devices such as temperature relief
valves or combined temperature and pressure
and pressure relief valves (see paragraphs 3.13
or 3.18) should discharge either directly or by
way of a manifold via a short length of metal
pipe (D1) to a tundish.
3.51 The diameter of discharge pipe (D1)
should be not less than the nominal outlet size
of the temperature relief valve.
3.52 Where a manifold is used it should
be sized to accept and discharge the total
discharge form the discharge pipes connected
to it.

16 Installation & Servicing Instructions
3.53 Where valves other than the
temperature and pressure relief valve from a
single unvented hot water system discharge by
way of the same manifold that is used by the
safety devices, the manifold should be factory
fitted as part of the hot water storage system
unit or package.
Tundish
3.54 The tundish should be vertical, located
in the same space as the unvented hot water
storage system and be fitted as close as
possible to, and lower than, the valve, with no
more than 600mm of pipe between the valve
outlet and the tundish (diagram 11 & Table 1,
page 18).
Note: To comply with the Water Supply (Water
Fittings) Regulations, the tundish should
incorporate a suitable air gap.
3.55 Any discharge should be visible at the
tundish. In addition, where discharges from
safety devices may not be apparent, e.g. in
dwellings occupied by people with impaired
vision or mobility, consideration should be
given to the installation of a suitable safety
device to warn when discharge takes place,
e.g. electronically operated.
Discharge pipe D2 (not supplied)
3.56 The discharge pipe (D2) from the
tundish should:
(a) have a vertical section of pipe at least
300mm long below the tundish before any
elbows or bends in the pipework (see diagram
1, G3), (diagram 11, page 18); and
(b) be installed with a continuous fall
thereafter of at least 1 in 200.
3.57 The discharge pipe (D2) should be
made of:
(a) metal; or
(b) other material that has been demonstrated
to be capable of safely withstanding
temperatures of the water discharged and is
clearly and permanently marked to identify
the product and performance standard (e.g.
as specified in the relevant part of BS 7291).
3.58 The discharge pipe (D2) should 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. for discharge
pipes between 9m and 18m the equivalent
resistance length should be at least two sizes
larger than the nominal outlet size of the
safety device; between 18 and 27m at least 3
sizes larger, and so on; bends must be taken
into account in calculating the flow resistance.
(See diagram 1, Table 1, G3), (diagram 11 &
Table 1, page 18 in these instructions) and the
worked example.
Note: An alternative approach for sizing
discharge pipes would be to follow Annex D,
section D.2 of BS 6700:2006 Specification for
design, installation, testing and maintenance
of services supplying water for domestic use
within buildings and their curtilages.
3.59 Where a single common discharge
pipe serves more than one system, it should
be at least one pipe size larger than the
largest individual discharge pipe (D2) to be
connected.
3.60 The discharge pipe should not be
connected to a soil discharge stack unless it can
be demonstrated that that the soil discharge
stack is capable of safely withstanding
temperatures of the water discharged, in which
case, it should:
(a) containamechanicalseal,notincorporating
a water trap, which allows water into the
branch pipe without allowing foul air from
the drain to be ventilated through the
tundish;
(b) be a separate branch pipe with no sanitary
appliances connected to it;
(c) if plastic pipes are used as branch pipes
carrying discharge from a safety device
they should be either polybutalene (PB) to
Class S of BS 7291-2:2006 or cross linked

Installation & Servicing Instructions 17
polyethylene (PE-X) to Class S of BS 7291-
3:2006; and
(d) be continuously marked with a warning
that no sanitary appliances should be
connected to the pipe.
Note:
1. Plastic pipes should be joined and
assembled with fittings appropriate to the
circumstances in which they are used as set
out in BS EN ISO 1043-1.
2. Where pipes cannot be connected to the
stackitmaybepossibletorouteadedicated
pipe alongside or in close proximity to the
discharge stack.
Termination of discharge pipe
3.61 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.
3.62 Examples of acceptable discharge
arrangements are:
(a) to a trapped gully with the end of the pipe
below a fixed grating and above the water
seal;
(b) 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 a wire cage
or similar guard is positioned to prevent
contact, whilst maintaining visibility; and
(c) discharges at high level: e.g. into a metal
hopper and metal downpipe with the end
of the discharge pipe clearly visible or
onto a roof capable of withstanding high
temperature discharges of water and 3m
from any plastic guttering system that
would collect such discharges.
3.63 The discharge would consist of high
temperature water and steam. Asphalt, roofing
felt and non-metallic rainwater goods may be
damaged by such discharges.
Worked example of discharge pipe sizing
Diagram11,page18:showsaG1/2temperature
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, page 18:
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 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 valves equates to 18m.
Subtract the resistance of 4 No. 28mm elbows
at 1.0m each = 4.0m
Therefore the maximum permitted length
equates to: 14m
As the actual length is 7m, a 28mm (D2) copper
pipe will be satisfactory.
WARNINGS:
• Undernocircumstancesshouldthefactory
fitted temperature/pressure relief valve
be removed other than by a competent
person. To do so will invalidate any
guarantee or claim.
• Thecoldwatercombinationvalveassembly
must be fitted on the PremierPlus water
supply to the PremierPlus cylinder.
• 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.

18 Installation & Servicing Instructions
Table 1 Sizing of Copper Discharge Pipes (D2) for Common T&P Relief Valve Sizes
600mm maximum
300mm
minimum
Safety device
(e.g. Temperature
relief valve) Metal discharge pipe (D1) from
Temperature relief valve to tundish
Tundish
Discharge below
xed grating
(Building Regulation
G3 section 3.61 gives
alternative points
of discharge)
Fixed grating
Trapped
gully
Discharge pipe (D2 from tundish,
with continuous fall. See Building
Regulation G3 section 3.55,
Table 4 and worked example
VALVE
OUTLET SIZE
MINIMUM
SIZE OF
DISCHARGE
PIPE D1
MINIMUM SIZE
OF DISCHARGE
PIPR D2 FROM
TUNDISH
MAXIMUM RESISTANCE
ALLOWED, EXPRESSED
AS A LENGTH OF
STRAIGHT PIPE
RESISTANCE
CREATED BY
EACH ELBOW OR
BEND
G 1/2 15mm
22mm
28mm
35mm
UP TO 9M
UP TO 18M
UP TO 27M
0.8M
1.0M
1.4M
G 3/4 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
NOTE: The above table is based on copper tube. Plastic pipes may be of different bore and
resistance. Sizes and maximum lengths of plastic should be calculated using data prepared for
the type of pipe being used.
Diagram 11 - Schematic Discharge Pipe Arrangement

Installation & Servicing Instructions 19
5.8 Primary (Central Heating) Pipework
Connections to the Electromax primary flow
and return must be in 22mm o/dia. pipe.
Isolating valves are fitted to the Electromax
unit on the primary flow and return connections
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 can be 9kW or 6kW, 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.
Use water soluble flux for making soldered
joints and ensure any flux residue is removed
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 pressurised the flexible hose of
the filling 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
(Shown tted
for lling)
Diagram 12 Primary Connections

20 Installation & Servicing Instructions
6.0 Installation - Electrical
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
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
property must be of sufficient current rating
and voltage for the Electromax and any other
electrical requirements for the property.
The consumer unit must be fitted with a
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 may be necessary to
fit a blanking plate 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, page 20 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 Sadia Specification Team or your
electricity supplier for further advice.
With an Off-Peak electrical supply there will be
twosetsofelectricaloutputsfrom 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.).
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 cable glands
previously fitted (see section 3.3, page 10). The
Live (Brown) conductor should be connected