Grant QR Range User guide

UK | DOC 0180 | Rev 1.0 | September 2021
Grant QR Range
Pre-Plumbed Indirect Heat Pump Cylinder
Installation, Servicing and User Instructions

GRANT ENGINEERING (UK) LIMITED
Hopton House, Hopton Industrial Estate, Devizes, Wiltshire, SN10 2EU
Tel: [phone] Fax: [phone]
Email: [email protected] www.grantuk.com
This manual is accurate at the date of printing but will be superseded and should be disregarded if specications and/or appearances are changed in the interests of continued product improve-
ment. However, no responsibility of any kind for any injury, death, loss, damage or delay however caused resulting from the use of this manual can be accepted by Grant Engineering (UK)
Limited, the author or others involved in its publication.
All good sold are subject to our o󰀩cial Conditions of Sale, a copy of which may be obtained on application.
© Grant Engineering (UK) Limited. No part of this manual may be reproduced by any means without prior written consent.
IMPORTANT NOTE FOR INSTALLERS
These instructions are intended to guide Installers on the
installation, commissioning and servicing of a Grant Quick
Recovery pre-plumbed indirect heat pump cylinder. After installing
the cylinder, leave these instructions with the user.
User instructions to guide users in the operation of the cylinder
are in Section 12 of these instructions.
SPECIAL TEXT FORMATS
The following special text formats are used in these instructions
for the purposes listed below:
! WARNING !
Warning of possible human injury as a consequence of not
following the instructions in the warning.
! CAUTION !
Caution concerning likely damage to equipment or tools
as a consequence of not following the instructions in the
caution.
! NOTE !
Used for emphasis or information not directly concerned
with the surrounding text but of importance to the reader.
PRODUCT CODES COVERED
Grant QR Pre-Plumbed Heat Pump
Cylinder Model
Product Code
210 litre QRSC210PP
250 litre QRSC250PP
300 litre QRSC300PP
SERVICING
The cylinder should be serviced at least every twelve months and
the details entered in the Service Log in Appendix C at the back of
these instructions.

1 INTRODUCTION 4
1.1 Installation requirements 4
1.2 Water supply requirements 4
1.3 Location 4
1.4 Storage and handling 4
1.5 About your cylinder 4
1.6 Open vented hot water systems 4
1.7 Primary circuit pipework 4
connections
1.8 Secondary circuit pipework 5
connections
1.9 Taps and ttings 5
1.10 Hard water scaling 5
1.11 Insulation 5
1.12 Health and Safety 5
2 TECHNICAL DATA 6
2.1 Cylinder technical data 6
2.2 Product contents 7
2.3 Cylinder dimensions 8
2.4 Optional plinth dimensions 9
3 PRIMARY CIRCUIT INSTALLATION 10
3.1 Grant QR pre-plumbed indirect heat 10
pump cylinders
3.2 Primary connections 10
3.3 Hard water areas 10
3.4 The 2-Port valve 10
4 SECONDARY CIRCUIT INSTALLATION 11
4.1 General 11
4.2 Cold water inlet manifold 11
4.3 Installation 11
4.4 Expansion vessel 12
4.5 Temperature and pressure relief 12
valve
4.6 Hot water supply 12
4.7 Prevention of scaling 12
4.8 Secondary return 12
4.9 Tundish 13
4.10 Discharge pipe 13
4.11 Discharge pipe sizing 13
4.12 Worked example 13
4.13 Discharge pipe arrangement 14
5 ELECTRICAL 15
5.1 Immersion heater 15
5.2 Immersion heater wiring instructions 15
5.3 Immersion heater safety cut-out 16
5.4 Dual thermostat 16
5.5 2-port valves 16
5.6 Pre-plumbed cylinder wiring 16
5.7 Greenbrook T205-C timer 16
5.8 Grant EP001 wiring centre 16
5.9 Wiring diagrams 17
Contents Page 3
6 COMMISSIONING, DRAINING DOWN 19
AND SAFETY
6.1 Filling the cylinder 19
6.2 Draining down 19
6.3 Immersion heater safety cut-out 19
6.4 Cold water discharge from tundish 20
6.5 Hot water discharge from tundish 20
6.6 Expansion vessel 20
6.7 Customer handover 20
7 MAINTENANCE 21
7.1 Servicing and maintenance 21
7.2 Inlet manifold assembly 21
7.3 Expansion relief valve cartridge 21
7.4 Expansion vessel 21
8 FAULT FINDING 22
8.1 Intermittent water discharge 22
8.2 Constant water discharge 22
8.3 No ow from hot water taps 23
8.4 Cold water ow from hot water taps 23
8.5 Excessive hot water from taps 24
9 SPARE PARTS 25
10 PRODUCT FICHE 26
11 END OF LIFE INFORMATION 26
12 USER INSTRUCTIONS 27
13 GUARANTEE 28
A DIGITAL DUAL THERMOSTAT 30
B GREENBROOK T205-C FUSED TIMER 33
SPUR SWITCH
C INSTALLATION, COMMISSIONING AND 36
SERVICE RECORD LOG BOOK
CONTENTS

Section 1: IntroductionPage 4
1.1 INSTALLATION REQUIREMENTS
Thank you for purchasing a Grant unvented hot water storage
cylinder from our QR range.
These Installation and User instructions must be read carefully
before you begin installing the cylinder.
The cylinder must be installed by a competent person in
compliance with all current legislation, codes of practice and
local by-laws covering the installation of an unvented hot water
cylinder.
Please also make sure that the installation complies with the
information contained in these Installation and User Instructions.
To prevent damage to the coil, cylinder and cylinder connections,
make any soldered joints before connecting pipework to the
cylinder.
1.2 WATER SUPPLY REQUIREMENTS
We recommend that your Grant unvented cylinder is installed with
an uninterrupted water supply.
Where possible, the unit should be fed via a Ø22 mm supply pipe.
It requires a supply pressure of at least 1.5 bar with a ow rate of
at least 25 litres per minute as a minimum for it to function.
Even with this pressure and ow rate, the ow from the outlets
will be disappointing if several outlets are used simultaneously.
Generally speaking, the higher the supply pressure, the better the
system will function.
The cylinder control equipment is factory set to limit the incoming
system operating pressure to 3 bar. The maximum supply
pressure into the pressure reducing valve (PRV) is 12 bar.
1.3 LOCATION
The unit is designed to be oor standing, vertically mounted,
internally in a frost-free environment. When choosing a suitable
location for the cylinder, consideration should be given to the
routing of the discharge pipe to a convenient point and also
the availability of an adequate power supply for connecting the
immersion heater.
The cylinder may stand on any at and level surface without any
special foundation requirements, provided that it is su󰀩ciently
robust to support the full weight of the cylinder (refer to Section
2.1).
The position of the cylinder should be such that easy access is
provided for servicing the controls and replacing the immersion
heater should the need arise.
Generally, pipe runs should be made as short as possible and
lagged to prevent heat loss.
Should it be required, a plinth for the cylinder is available to
purchase from Grant UK (product code: MB-24) to enable
pipework to be run underneath the cylinder with ease. Refer to
Section 2.4 for dimensions.
1.4 STORAGE AND HANDLING
If the cylinder is not being installed immediately, it should remain
in its carton to prevent damage. We recommend that the cylinder
be transported to its installation position on a sack truck or similar
whilst still within the carton.
! CAUTION !
Do not use the Temperature and Pressure relief valve (T&P
relief valve) as a handle when moving and positioning the
cylinder.
With pre-plumbed cylinders, do not use the pipework as a
carrying handle when lifting, moving and positioning the
cylinder.
1.5 ABOUT YOUR CYLINDER
Grant QR pre-plumbed indirect heat pump cylinders are factory-
tted with the following components:
Primary circuit pipework
• 1 x 22mm 2-port zone valve for hot water
• 2 x 22mm 2-port zone valves for heating (for two separate
heating zones)
• 2 x Manual air vents (one on coil ow pipe and the other on
coil return pipe)
• 1 x 22mm automatic by-pass
• 1 x 15mm approved lling loop
Cold water inlet pipework
• 1 x Cold water inlet manifold
• 1 x Temperature and pressure relief valve
• 1 x 15-22mm Tundish
• 2 x Drain cocks (one on cold water inlet pipework and
another at bottom of cylinder)
Electrical
• 1 x Grant EP001 Wiring Centre (pre-wired to the zone valves
and dual thermostat). Refer to Grant UK DOC 0176 for more
detailed information.
• 1 x 3kW electric immersion heater
• 1 x Greenbrook T205-C timer (for immersion heater)
• 1 x Dual thermostat (cylinder thermostat and high limit
thermostat)
Grant QR pre-plumbed indirect heat pump cylinders have a single
coil designed for connection to an air source heat pump, such as
the Grant Aerona³ range. If another heat source, such as a boiler
or another make of heat pump is to be connected, please refer to
the manufacturer’s installation instructions for more information.
The coil must be connected using a 2-port motorised valve
(factory tted) to shut o󰀨 the ow from the primary source and
electronically interlocked with the heat source via the cylinder
control and high limit thermostat.
Failure to t this 2-port valve will invalidate all guarantees and will
be in breach of the Building Regulations Approved Document G3
(2010). More information on electrical wiring is given in Section 5
of these instructions.
Please refer to Figure 2-1 for positions of the components tted to
these cylinders.
1.6 OPEN VENTED HOT WATER SYSTEMS
If required, your Grant QR indirect heat pump cylinder can be
used as part of an open vented hot water system, i.e. fed from
a cold water storage cistern and tted with an open vent pipe,
provided the maximum head does not exceed 30 metres.
When used in this way, it will not be necessary to install the
expansion vessel supplied with the cylinder.
! NOTE !
The temperature and pressure relief (T&P) valve must be
left connected to the cylinder (as supplied).
As it may still operate due to temperature, the temperature
and pressure relief (T&P) valve should be connected in the
correct manner - refer to guidance given in Section 4 of these
instructions.
1.7 PRIMARY CIRCUIT PIPEWORK
CONNECTIONS
All primary circuit pipework connections to the cylinder MUST be
made in accordance with Figure 3-1. Refer to Section 3 (Primary
Circuit Installation).
1 INTRODUCTION

Section 1: Introduction Page 5
1.8 SECONDARY CIRCUIT PIPEWORK
CONNECTIONS
All secondary circuit primary pipework connections to the cylinder
MUST be made in accordance with Figure 2-1 and Section 4
(Secondary Circuit Installation).
1.9 TAPS AND FITTINGS
All taps and ttings incorporated in the unvented hot water system
should have a rated operating pressure of 7 bar or above.
The compression nuts and olives required to make the secondary
return and hot water draw-o󰀨 connections to the cylinder are
supplied loose in the accessories pack provided with the cylinder.
1.10 HARD WATER SCALING
If the cylinder is used in a hard water area scaling will form
inside the cylinder and this will reduce both the performance and
working life of the cylinder.
Where the total hardness exceeds 125 ppm a high capacity water
softener, or suitable water conditioner, should be installed in the
incoming cold water supply to the cylinder.
The cylinder immersion heater control thermostat has been
factory-set to around 65°C. Please refer to Section 5.1 for further
information on the immersion heater/s supplied.
The water temperature control thermostats (on the immersion
heaters and dual thermostats) tted to the cylinder should be
set no higher than 65°C, however this could be decreased
to be between 50°C and 55°C depending on the end user’s
requirements.
Setting a lower target temperature will help to minimise the build-
up of lime scale and is likely to increase the longevity of the hot
water cylinder.
1.11 INSULATION
All Grant QR pre-plumbed indirect heat pump cylinders are
insulated with a 50mm layer of CFC/HCFC free, re retardant,
polyurethane foam injected between the stainless steel cylinder
and the outer casing. This polyurethane foam has a Global
Warming Potential (GWP) of 3.1 and an Ozone Depletion
Potential (ODP) of 0.
1.12 HEALTH AND SAFETY
The information supplied in Table 2-1 will help you assess the
safest way to manoeuvre your cylinder into position.
Please use the table to nd the empty weight of your cylinder and
then consider how you can safely move it into its nal position.
Please leave these Installation and User Instructions with the
householder after installation.

2.1 CYLINDER TECHNICAL DATA
Table 2-1: Cylinder technical data
Grant QR pre-plumbed indirect heat pump cylinders
210 litre 250 litre 300 litre
Nominal capacity (litres) 210 250 300
Actual capacity (litres) 197 237 289
Overall diameter (mm) 550 550 550
Overall height 1493 1744 2057
Weight - empty (kg) 59 67 73
Weight - full (kg) 256 304 362
Secondary return connection (mm) 22 22 22
Cold feed / hot draw-o󰀨 connections (mm) 22 22 22
Primary coil connections (mm) 22 22 22
Primary coil length (m) 26 26 26
Primary coil surface area (m²) 2.3 2.3 2.3
Primary coil pipe diameter (mm) 28 28 28
Maximum water supply pressure (bar) 12 12 12
System operating pressure - pre-set (bar) 3 3 3
Expansion vessel charge pressure (bar) 3 3 3
Expansion relief valve pressure (bar) 6 6 6
T&P relief valve lift pressure (bar) 7 7 7
T&P relief valve lift temperature (°C) 90 90 90
Maximum primary circuit working pressure (bar) 3.5 3.5 3.5
Performance:
Primary coil rating (kW) 32.0 32.0 34.0
Standing heat loss (kWh/24hrs)* 1.79 2.02 2.24
* Test carried out at 60°C.
Section 2: Technical DataPage 6
2 TECHNICAL DATA

Section 2: Technical Data Page 7
2.2 PRODUCT CONTENTS
Table 2-2: Product contents (QRSCPP models)
Grant QR pre-plumbed indirect heat pump cylinders
210 litre 250 litre 300 litre
Cylinder assembly 111
Expansion vessel - 19 litre 1 1 -
Expansion vessel - 24 litre - - 1
½ʺ temperature and PRV - 7 bar/90°C † 111
Tundish - 15/22 mm † 111
22mm compression nut and olive 2 2 2
3/4” BSPM x 22mm compression adapter 111
Drain cock - ½ʺ end feed † 222
Inlet manifold - 3 bar PRV and 6 bar expansion relief valve † 111
2-port motorised valve - 22 mm † 333
Dual thermostat (control: 25-65°C / high limit: 80°C) † 111
Immersion heater - 3kW 1¾ʺ boss † 111
† Factory tted

Section 2: Technical DataPage 8
Figure 2-1: Grant Pre-Plumbed QR indirect heat pump cylinder dimensions
Table 2-3: Pre-plumbed cylinder dimensions
Dimensions
(mm) 210 litre 250 litre 300 litre
A 1150 1400 1600
B 1269 1519 1832
Height 1493 1744 2057
Diameter 550 550 550
2.3 CYLINDER DIMENSIONS
316
1410
200
276
A
HEIGHT
HW DRAW OFF 22mm
COLD WATER INLET
MANIFOLD 22mm
DRAIN COCK 2
RETURN TO HEAT PUMP - 28mm
RETURN FROM HEATING CIRCUITS - 28mm
FLOW FROM HEAT PUMP - 28mm
FLOW TO HEATING ZONE 3 - 22 mm
(OPTIONAL, PIPE BLANKED)
FLOW TO HEATING ZONE 2 - 22 mm
FLOW TO HEATING ZONE 1 - 22 mm
DRAIN COCK 1
PRIMARY CIRCUIT BYPASS
FILLING LOOP
TUNDISH (15/22mm)
PTRV (90°C / 7BAR)
INDIRECT COIL FLOW
CONNECTION 22mm
(WITH MANUAL AIR VENT)
FLOW SETTER FOR
PRIMARY CIRCUIT
BYPASS
PRIMARY SYSTEM
PRESSURE GAUGE
3kW IMMERSION
HEATER (1¾” BOSS)
GRANT EP001
WIRING CENTRE
SECONDARY
RETURN 22mm
STAT
POCKET 10mm
DIGITAL DUAL
THERMOSTAT
GREENBROOK
T205-C TIMER
Diameter
B
INDIRECT COIL RETURN
CONNECTION 22mm
(WITH MANUAL AIR VENT)
STAT
POCKET 10mm

Section 2: Technical Data Page 9
2.4 OPTIONAL PLINTH DIMENSIONS
100
R 275 422
416
Figure 2-2: Grant QR Cylinder Plinth (product code: MB-24)
Figure 2-3: Grant QR Cylinder Plinth dimensions

Section 3: Primary Circuit InstallationPage 10
3.1 GRANT QR PRE-PLUMBED INDIRECT
HEAT PUMP CYLINDERS
Grant QR pre-plumbed indirect heat pump cylinders are
specically designed for connection to most fully pumped Air
Source Heat Pump systems (such as the Grant Aerona³ Heat
Pump range) - either open vented or sealed systems having a
maximum working pressure of 3.5 bar and a maximum working
temperature of 90ºC.
If you are in any doubt over the suitability of an Air Source Heat
Pump (other than a Grant Aerona³ heat pump) for use with the
cylinder, consult the heat pump manufacturer.
! WARNING !
Solid fuel or wood burning boilers and gravity circulation
systems must not be used on the primary circuit of an
unvented hot water system.
3.2 PRIMARY CONNECTIONS
Grant QR pre-plumbed indirect heat pump cylinders are factory
tted with primary circuit pipework that includes the following
components:
• 1 x 2-port zone valve for hot water
• 2 x 2-port zones valves for heating (for two separate heating
zones)
• 1 x Blanked pipe tail for a third heating zone if required
• 1 x Digital dual thermostat (Cylinder thermostat and High
Limit thermostat)
• 2 x Manual air vents (one on the ow into the indirect coil and
another on the return from the indirect coil)
• 1 x 22mm system bypass with ow setter
• 1 x Approved lling loop to ll the primary circuit
Make the primary circuit and heat pump connections to the
cylinder as follows (Refer to Figure 3-1):
1. The primary ow and return connections from the heat pump
should be made to cylinder connections D and F respectively
(refer to Figure 3-1 and Table 3-1).
2. The primary ow to heating zone 1 should be made to
cylinder connection A (refer to Figure 3-1 and Table 3-1).
3. The primary ow to heating zone 2 should be made to
cylinder connection B (refer to Figure 3-1 and Table 3-1).
4. If required, the primary ow to heating zone 3 should be
made to cylinder connection C (refer to Figure 3-1 and Table
3-1).
If a third heating zone is required, the tail of pipe C (see
Figure 3-1) will need to be trimmed as it has been soldered
shut during production.
! CAUTION !
If a third heating zone is to be connected to cylinder
connection C (refer to Figure 3-1), the pipe tail should be
cut using a pipe slicer or pipe cutter - to leave the pipe
ends with a slight radius and free from any burrs or sharp
edges.
This pipe tail should not be cut square using a hacksaw.
5. When lling the primary circuit, the manual air vents situated
on the ow and return connections to the indirect coil can
be used to vent air from the indirect coil (refer to item G in
Figure 3-1).
3 PRIMARY CIRCUIT INSTALLATION
A B C D E F
GG
Table 3-1: Key to Figure 3-1
Item Description
A 22mm Flow to heating zone 1
B 22mm Flow to heating zone 2
C22mm Flow to heating zone 3 (optional)
D28mm Flow from ASHP
E 28mm Return from heating circuits
F28mm Return to ASHP
G Manual air vent
Figure 3-1: Primary circuit connections
3.3 HARD WATER AREAS
If the cylinder is to be used with a boiler, in a hard water area, we
recommend that the primary ow temperature be limited to 75°C.
This will help reduce the migration of suspended solids in the
water and help prevent the build up of lime scale.
3.4 THE 2-PORT VALVE
To prevent gravity circulation when the heat pump switches o󰀨,
three 2-port motorised valves have been supplied tted to the
cylinder after the primary ow pipe from the ASHP (see item D,
Figure 3-1). They should be wired in accordance with Figures
5-2 and 5-3 to ensure that, when used with a Grant Aerona³ Heat
Pump, the installation will comply with current legislation.
For boilers or other makes of heat pump please check with the
manufacturer for connection details.

Section 4: Secondary Circuit Installation Page 11
4.1 GENERAL
Grant QR pre-plumbed indirect heat pump cylinders are supplied
with all the necessary safety devices and components required for
an unvented hot water system. For a list of these safety devices
and components refer to Table 2-2 in these Installation and User
instructions.
These pre-plumbed cylinders are supplied with the safety devices
and components factory tted, requiring only the following to be
carried out by the installer:
• Connect the cold water supply pipe to the cold water inlet
manifold. Refer to Sections 4.2 and 4.3 for details.
• Connect the expansion vessel. Refer to Sections 4.3 and 4.4
for details.
• Connect the discharge pipe to the outlet of the Tundish.
Refer to Section 4.9 for details.
For commissioning and maintenance purposes, it is essential to
t a service valve (not supplied) in the cold water supply pipe,
immediately before the inlet manifold.
The ½ʺ drain cock is factory tted (refer to Figure 2-1 for location)
in the cold feed to the cylinder to provide a means of draining the
unit.
4.2 COLD WATER INLET MANIFOLD
This manifold contains a pressure reducing valve, double check
valve and expansion relief valve with a stainless steel seat.
The pressure reducing valve is factory set to 3 bar. The set
pressure is shown on top of the valve. The maximum inlet
pressure to this valve is 12 bar.
A balanced cold water connection is provided on the inlet
manifold. Refer to Figure 4-1. This should only be used to provide
balanced cold supplies to shower valves and mixer taps. If the
balanced cold water outlet is not required, blank o󰀨 this port.
4.3 INSTALLATION
1. Cold water supply pipe to be 22mm nominal size.
2. Flush supply pipework before connection to remove all ux
and debris prior to tting the inlet controls.
Failure to do this may result in irreparable damage to the
controls and will invalidate the warranty.
3. Once the pipework is ushed connect the cold supply to the
Inlet manifold. Refer to Figure 2-1 for location and Figure 4-1
for a detailed drawing of the manifold.
4. The expansion relief valve should be either horizontal or
upright - if tted inverted, debris may be deposited on the
seat and cause fouling of the seat when the valve operates.
Check direction of ow arrows.
5. If the installation requires one, a pressure gauge should be
sourced and tted on the cold water supply to the cylinder,
between the inlet manifold and the cold water inlet tapping on
the cylinder.
6. Connect the expansion vessel directly to the ¾” BSPF
connection in the inlet valve manifold body, after removing
the black plastic plug (see Figure 2-1 for location and Figure
4-1 for a detailed drawing of the manifold). Refer to Section
4.4 for more information on tting the expansion vessel.
7. The expansion relief drain and the T&P relief valve are both
connected to the tundish (see Figure 2-1). This pipework
must be connected to a safe visible discharge point via
the tundish (supplied tted) and the pipework must have
a continuous fall. Refer to Sections 4.9 to 4.13 for further
information on the Tundish and Discharge pipe.
8. The pressure reducing valve has two outlets, the second one
is for a balanced cold water supply, to a shower or a bidet
(over rim type only, ascending spray type requires type AA,
AB or AD air gap).
Major shower manufacturers advise tting a mini expansion
vessel in the balanced cold supply to accommodate thermal
expansion and prevent tightening of shower controls.
If the dwelling has a shower mixing valve (manual or
thermostatic) or a Bidet (over rim type) use the cold water
supply from the balanced cold water connection on the inlet
manifold for these outlets.
Do not use the balanced cold connection to supply bath taps
as this can reduce the ow of water available to the cylinder.
If the balanced cold water outlet is not required, blank o󰀨 the
connection.
9. The Service Log at the back of these instructions should be
completed after commissioning of the system.
10. The cylinder must be registered with Grant UK within 30 days
of installation. Refer to Section 13 for further details on the
Cylinder guarantee.
4 SECONDARY CIRCUIT INSTALLATION
Figure 4-1: Cold water inlet manifold
Expansion
relief valve
Pressure
reducing valve
Circlip
Balanced cold
outlet
¾” BSPF expansion vessel
connection.
(Remove black plug prior to
connection)
Expansion
relief
Cold inlet
to cylinder
Cold water
supply

Section 4: Secondary Circuit InstallationPage 12
4.4 EXPANSION VESSEL
A suitable expansion vessel with a pre-charge pressure of 3bar is
supplied for tting to all cylinders.
This expansion vessel must be connected into the cold water
supply, between the expansion relief valve (in the inlet manifold)
and the cold water inlet to the cylinder.
The preferred method of connection is to hard pipe the expansion
vessel directly to the ¾” BSPF connection in the inlet valve
manifold body using 22mm diameter pipe. Refer to Figure 4-1.
To do this, with the cylinder in its nal position and with all primary
circuit connections to the cylinder made:
1. Remove the black plastic plug from the inlet manifold body
(refer to Figure 4-1).
2. Screw the ¾” BSPM x 22mm compression adapter (supplied)
into the ¾” BSPF connection in the inlet manifold body.
3. Mount the expansion vessel in a suitable position on an
adjacent wall to the cylinder using the wall brackets on the
vessel.
! NOTE !
The expansion vessel must be positioned with the
connection point at the bottom.
No valve should be tted between the expansion vessel
and the cylinder.
4. Using 22mm diameter pipe and the 22mm compression nut
and olive supplied with the expansion vessel, connect the
expansion vessel to the inlet manifold.
The air charge pressure in the expansion vessel must be regularly
checked (e.g. at every service) and topped up as necessary. The
correct air charge pressure is 3.0bar.
Refer to Sections 7.1 and 7.4 for further details.
4.5 TEMPERATURE AND PRESSURE
RELIEF VALVE
The temperature and pressure relief valve (T&P Valve) is supplied
factory tted to the cylinder. The T&P valve must not be removed
from the cylinder or tampered with in any way. The valve is pre-set
to lift at 7bar or 90°C and any attempt to adjust it will invalidate the
guarantee.
4.6 HOT WATER SUPPLY
Connect the hot water supply pipe to the top outlet of the cylinder.
Refer to Figure 2-1.
4.7 PREVENTION OF SCALDING
Building Regulations Approved Document G (Part G3) requires
that the hot water temperature supplied to a bath should be
limited to a maximum of 48°C by using an in-line blending valve
(not supplied with the cylinder) with a maximum temperature stop.
The length of the supply pipe between the blending valve and the
bath hot water outlet should be kept to a minimum to prevent the
colonisation of waterborne pathogens (e.g. legionella). Refer to
Approved Document G for further details.
4.8 SECONDARY RETURN
All Grant QR pre-plumbed indirect heat pump cylinders are tted
with a secondary return connection. If a secondary return circuit is
required it should be connected to the cylinder as shown in Figure
4-2.
! NOTE !
If a secondary circulation circuit is installed then a larger
expansion vessel may be required to handle the increase
in volume.
Balanced cold supply for showers
or bidet only (see Section 4.2)
Secondary
return line Circulation
pump
Non return
valve
Cold inlet
Balanced cold
supply outlet
.
Figure 4-2: Secondary return circuit

Section 4: Secondary Circuit Installation Page 13
4.9 TUNDISH
A suitable tundish is supplied tted to the outlets from the T&P
relief valve and expansion relief valve.
The tundish should be vertical, located in the same space as
the unvented hot water cylinder and be tted as close to, and
lower than, the T&P valve with no more than 600mm of pipe (D1)
between the valve outlet and the tundish.
! WARNING !
The tundish must NOT be positioned above or in close
proximity of any electrical current carrying devices or
wiring.
A discharge pipe must be tted to the outlet of the tundish. This
must conform to the requirements as given in Sections 4.10 to
4.13 of these Installation and User Instructions.
4.10 DISCHARGE PIPE
1. 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.
a) It should be made of metal or other material that has
been demonstrated to be capable of withstanding
temperatures of the water discharged.
b) Be at least one pipe size larger than the normal 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 long
the equivalent resistance length should be at least two
sizes larger than the normal outlet size of the safety
device, between 18m and 27m at least three sizes larger
and so on.
Bends must be taken into account in calculating the ow
resistance. Refer to Sections 4.11, 4.12 and 4.13.
c) Have a vertical section of pipe at least 300 mm long,
below the tundish before any elbows or bends in the
pipe work.
d) Be installed with a continuous fall of 1:200 (0.286°).
e) Have discharges visible at both the tundish and the
nal point of discharge but where this is not possible or
practically di󰀩cult there should be clear visibility at one
or other of these locations.
2. Examples of acceptable discharge arrangements are:
a) ideally below a xed grating and above the water seal in
a trapped gully.
b) downward discharges at a 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 in to
contact with discharges, a wire cage or similar guard
is positioned to prevent contact, whilst maintaining
visibility.
c) 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 systems that
would collect such discharges (tundish visible).
3. Where a single pipe serves a number of discharges, such as
in blocks of ats, the number served should be limited to not
more than 6 systems so that any installation can be traced
reasonably easily.
The single common discharge pipe should be at least one
pipe size larger than the largest individual discharge pipe to
be connected.
If unvented hot water storage systems are installed where
discharges from safety devices may not be apparent i.e.
in dwellings occupied by blind, inrm or disabled people,
consideration should be given to the installation of an
electronically operated device to warn when a discharge
takes place.
! NOTE !
The discharge will consist of scalding water and steam.
Asphalt, roong felt and non-metallic rainwater goods may
be damaged by such discharges.
4.11 DISCHARGE PIPE SIZING
Refer to Table 4-1 (discharge pipe sizing).
Table 4-1: Discharge pipe sizing
Valve outlet
size
Diameter
(inches)
Minimum
size of
discharge
pipe D1
(mm)
Minimum
size of
discharge
pipe D2
from
tundish
(mm)
Maximum
resistance
allowed,
expressed
as a length
of straight
pipe, i.e. no
elbows or
bends (m)
Resistance
created by
each elbow
or bend (m)
½ 15
22
28
35
Up to 9
Up to 18
Up to 27
0.8
1.0
1.4
¾ 22
28
35
42
Up to 9
Up to 18
Up to 27
1.0
1.4
1.7
1 28
35
42
54
Up to 9
Up to 18
Up to 27
1.4
1.7
2.3
! NOTE !
The above table is based on copper tube. Plastic pipes
may be of a di󰀨erent bore and resistance.
Sizes and maximum lengths of plastic pipe should be
calculated using data for the type of pipe being used.
4.12 WORKED EXAMPLE
The example below is for a 1/2” diameter temperature relief valve
with a discharge pipe (D2) having 4 x 22mm elbows and a length
of 7 m from the tundish to the point of discharge.
From Table 4-1:
Maximum resistance allowed for a straight length of 22mm copper
discharge pipe (D2) from a 1/2” diameter temperature relief valve
is 9.0m.
Subtract the resistance for quantity of 4 x 22mm elbows at 0.8m
each = 3.2m.
Therefore, the maximum permitted length is 9.0 - 3.2 = 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 copper
discharge pipe (D2) from a 1/2” diameter temperature relief valve
is 18m.
Subtract the resistance for a quantity of 4 x 28mm elbows at 1.0m
each = 4m.
Therefore, the maximum permitted length is 18 - 4 = 14m.
As the actual length is 7m, a 28mm diameter copper pipe will be
satisfactory in this case.

Section 4: Secondary Circuit InstallationPage 14
4.13 DISCHARGE PIPE ARRANGEMENT
Safety device (e.g.
temperature relief valve)
Metal
discharge
pipe from
safety device
Metal
discharge pipe from tundish
with
continuous fall. See table and
worked
example on previous page
Discharged below
fixed grating
Fixed grating
Trapped gully
Tundish
600mm max
300mm min
Figure 4-3: Typical discharge pipe arrangement

Section 5: Electrical Page 15
All electrical wiring must be carried out by a competent person
and in accordance with the current edition of BS7671 (the I.E.T.
Wiring Regulations), including any amendments.
The control equipment supplied must be wired according to these
Installation and User Instructions to ensure that the cylinder
functions safely.
From an economic and convenience point of view, it is intended
that these controls operate in conjunction with other control
packages, for example, an “S-plan” type system that incorporates
a programmer, etc.
5.1 IMMERSION HEATER
All Grant QR pre-plumbed indirect heat pump cylinders are
supplied factory-tted with one 3kW immersion heater. This
immersion heater conforms to EEC Directive 76/889 for radio
interference and complies with EN 60335-2-73.
The BEAB approval certication on this immersion heater only
applies if a Thermowatt RTS rod type thermostat is used.
The control thermostat is pre-set on position “• •” at a temperature
of approximately 65°C. Refer to Figure 5-1.
Installation and wiring instructions for the immersion heater are
supplied with each unit. The wiring connections are also shown
in Figure 5-1. Follow the wiring instructions connecting the live,
neutral and earth as indicated.
The immersion heater must be permanently connected to the
electrical supply via the Greenebrook T205-C timer (factory
tted) which incorporates a double-pole isolator and is fused
at 13 amps. Refer to Section 5.7 for further information on the
Greenbrook T205-C timer and Figures 5-2 and 5-3 for connection
details. A safety cut-out is also incorporated within the thermostat
and is factory set to operate at 75°C.
The immersion heater is factory tted to the cylinder. If the
immersion heater needs to be replaced it must be tted to
the cylinder using the gasket provided on the unit. Only use a
correctly shaped spanner. Stilsons or pipe grips should not be
used. The use of sealing compound is not recommended.
! WARNING !
The immersion heater must NOT be used unless it is fully
immersed in water.
Always ensure that the cylinder and bu󰀨er are full of water
BEFORE switching on the electrical supply.
Refer to Figure 2-1 for the position of the immersion heater.
5.2 IMMERSION HEATER WIRING
INSTRUCTIONS
Ensure that the supply voltage corresponds to the voltage rating
of the immersion heater as shown on the rating label on the
terminal cover.
Each 3kW 230V 50Hz-immersion heater should be wired in
accordance with the instructions given in Figure 5-1.
The cable must be routed through the strain relief bush. The cable
grip should be secured using only the screws provided.
The 230V 50Hz power supply for the immersion heater should
be wired to the Greenbrook T205-C timer (factory tted), which
incorporates a double pole isolator switch and is independently
fused at 13 amps. Refer to Section 5.7 for further information
on the Greenbrook T205-C timer and Figures 5-2 and 5-3 for
connection details.
If this timer is to be bypassed for some reason, the immersion
heater should be wired through a double pole isolator switch or
suitable controller, with a minimum break capacity of 13 amp and
contact separation of at least 3mm.
Use 85°C heat resistant rubber insulated HOFR sheathed exible
cable, with minimum cross sectional area of 1.5mm², to comply
with BS 6141 table 8 and must be fully earthed.
! WARNING !
Always ensure that the immersion heater cap is not
covered.
= Earth (Green/Yellow)
= Neutral (Blue)
= Live (Brown)
Temperature
control dial
Reset
button
Figure 5-1: Immersion heater wiring connections
! WARNING !
This immersion heater must be earthed.
! WARNING !
The manual reset high limit thermostat must not under any
circumstances by by-passed. This is pre-set to 75°C and to
prevent nuisance tripping, the control thermostat should
always be left in position • •.
5 ELECTRICAL

Section 5: ElectricalPage 16
5.3 IMMERSION HEATER SAFETY CUT-OUT
The immersion heater incorporates an in independent non self-
resetting over temperature cut-out device to prevent excessive
water temperatures.
In normal operation the reset pin positioned to the side of the
control knob and indicated by a triangle (with the words ‘bipolar
safety’ above) will be approximately 2-3mm below the upper
surface of the thermostat cap.
Should the over temperature cut-out operate, the reset pin will be
pushed upwards to become level with or slightly above the cover.
Wait until the temperature has fallen su󰀩ciently. Then Investigate
and identify the cause of the cut-out operation and rectify the fault.
Then manually reset the cut-out by pressing in the reset pin to its
normal operating position using hand pressure only with a suitably
sized implement.
! WARNING !
Before removing the immersion heater covers to either
reset the safety cut-out or check/alter the thermostat
setting, ensure that the electrical supply is isolated.
Ensure the cover to the immersion heater cover is replaced
correctly and the retaining nut is tted. Finally switch the mains
electricity supply back on.
5.4 DIGITAL DUAL THERMOSTAT
A Digital Dual Thermostat (a combined control and high limit
thermostat) is supplied factory tted to the Grant QR pre-plumbed
indirect heat pump cylinder to control the operation of the heat
pump primary coil. Refer to Figure 2-1 for position.
The cylinder control thermostat has an adjustment range between
25°C and 65°C. It is recommended that it is set to 60°C.
The high limit (overheat) thermostat will automatically operate at
80°C.
For details on wiring connections, refer to Figures 5-2 and 5-3.
For more detailed information on the Digital Dual Thermostat
supplied with this cylinder, please refer to Appendix A at the back
of these instructions.
! NOTE !
Upon rst use it will be necessary to reset the digital dual
thermostat.
To do this, please refer to steps 1-3 outlined in Section
A.1.2 at the back of these instructions.
! NOTE !
The Digital Dual Thermostat supplied with all Grant QR pre-
plumbed cylinders requires a permanent live connection.
Refer to Figures 5-2 and 5-3 for wiring details.
! WARNING !
The Digital Dual Thermostat supplied with all Grant QR pre-
plumbed cylinders is not suitable for use with a Y-plan type
control system using a Honeywell V4073A mid-position
zone valve (or similar).
5.5 2-PORT VALVES
To comply with the regulations governing the installation of indirect
unvented hot water cylinders, a 2-port motorised valve must be
tted in the primary ow to prevent gravity circulation when the
boiler switches o󰀨.
This acts as a positive energy cut-out should the high limit
(overheat) thermostat (in the dual thermostat) operate. If this
happens, the 2-port zone valve will operate and shut o󰀨 the
primary ow to the cylinder.
When installed as part of an “S-plan” type of heating control
system, this motorised valve will also control the temperature of
the domestic stored water via the cylinder control thermostat,
(located in the dual thermostat).
This valve should be wired in accordance with Figure 5-2 to
comply with current legislation.
For other makes of air source heat pump, other than the Grant
Aerona³, consult the heat pump manufacturer for electrical
connection details.
5.6 PRE-PLUMBED CYLINDER WIRING
The Grant QR pre-plumbed indirect heat pump cylinder is
supplied factory tted with the following electrical equipment:
• 1 x Grant EP001 Wiring Centre (pre-wired to the zone
valves and dual thermostat). Refer Section 5.8 for further
information.
• 2 x 2-port zone valves for space heating (for two separate
heating zones)
• 1 x 2-port zone valve for hot water heating
• 1 x 3kW electric immersion heater
• 1 x Greenbrook T205-C timer (for immersion heater)
• 1 x Dual thermostat (cylinder thermostat and high limit
thermostat)
These are pre-wired to the factory-tted Grant EP001 wiring
centre mounted on the cylinder. Refer to Section 5.8 and Figures
5-2 and 5-3 for details.
5.7 GREENBROOK T205-C TIMER
Grant QR pre-plumbed indirect heat pump cylinders are supplied
with a Greenbrook T205-C timer factory tted, to control the
operation of the immersion heater for anti-legionella purposes.
Please refer to Grant UK DOC 0136 for detailed information on
anti-legionella regimes.
Please refer to Figures 5-2 and 5-3 for connection details and
Appendix B at the back of these instructions for information on
how to set the Greenbrook T205-C timer.
5.8 GRANT EP001 WIRING CENTRE
The Grant EP001 wiring centre is supplied factory tted to Grant
QR pre-plumbed indirect heat pump cylinders and is wired as
shown in Figure 5-2.
The Grant EP001 wiring centre has been designed as a simple
and convenient means of making all system control connections
for up to four space heating zones, plus one hot water zone, in
one wiring centre, with optional capability to provide both volt free
outputs and automatic DHW priority (for Grant Aerona³ heat pump
installations).
For further information on the Grant EP001 wiring centre, please
refer to Grant UK DOC 0176.
! NOTE !
All earth connections for electrical components connected
to the EP001 wiring centre should be made to the brass
earth bar on the inside of the EP001 wiring centre
enclosure.

Section 5: Electrical Page 17
Figure 5-2: Grant QR pre-plumbed indirect heat pump cylinder wiring diagram
5.9 WIRING DIAGRAMS
The wiring diagram shown below demonstrates how the electrical components supplied with the Grant QR pre-plumbed
indirect heat pump cylinder are wired from the factory.
* in order to achieve independent time control for the DHW zone, the link between terminals 33 and 34 of the EP001 wiring centre must
be removed before connecting your chosen time control option. For detailed information on the operation of the Grant EP001 wiring
centre, please refer to Grant UK DOC 0176.
2
GRANT
EP001 - Wiring centre.
Issue 5
Mains
Power
LED8
LED1 LED2 LED3 LED4 LED7
C2 C1
VAR2 VAR1
LED6 LED5
S1
Hot Water
Priority
RL1 RL2
RL3
RL4
F1 1A F2 1A F3 1A F4 1A F5 3.15A F6 5A F8 1AF7 6.3A
DANGER HIGH VOLTAGE |
All Fuses
230Vac Anti-surge
1 2 3 4 58 9 10 11 14 15 16 17 20 21 22 23
N L N L N L
34 35 36 376 7 12 13 18 19 24
L N
33 38
3940414344454647 424849505152
L L L L L N L L L L L N L L L L L N L L L L L N L L L L L N
Spare
Clock Stat Pump Clock Stat Pump Clock Stat Pump Clock Stat Pump Clock
Cyl
Stat Pump
Heating
Hot water
HMI
INOUT NC2 C2 NO2 NO1 C1 NC1 OP2 OP1
26 27 28 2925 30 31 32
Motor HW
2-Port Zone Valve
- DHW -
Motor HTG
2-Port Zone Valve
- Zone 2 -
Do not
connect
Motor HTG
2-Port Zone Valve
- Zone 1 -
Do not
connect
Do not
connect
Do not
connect
Do not
connect
Do not
connect
ON
OFF
Digital
Dual Thermostat
L N C1
N L
Hot Water
Immersion
Heater
N L
LOAD
SUPPLY
N L
Greenbrook T205-C
Immersion Timer
(indepently switched and
fused at 13A)
Brown
Blue Orange
Grey
Orange
Grey
Orange
Grey
G/Y
G/Y
Brown
Blue
Brown
Blue
G/Y
Grey
Black
Blue
Brown
Brown
Blue
G/Y
Link*

Section 5: ElectricalPage 18
Figure 5-3: Grant QR pre-plumbed indirect heat pump cylinder connected to a Grant Aerona³ ASHP, as part of a S-Plan plus type
system with UFH (Grant UH8 Wiring Centre) and a radiator circuit
The control system shown in this diagram shows the “hot water priority” switch on the EP001 wiring centre in the left hand
‘ON’ position. This ensures that there can be no demand for space heating and hot water at the same time.
For information regarding the operation of the Greenbrook T205-C timer shown in this control system wiring diagram, please
refer to Appendix B at the back of these installation instructions.
2
GRANT
EP001 - Wiring centre.
Issue 5
Mains
Power
LED8
LED1 LED2 LED3 LED4 LED7
C2 C1
VAR2 VAR1
LED6 LED5
S1
Hot Water
Priority
RL1 RL2
RL3
RL4
F1 1A F2 1A F3 1A F4 1A F5 3.15A F6 5A F8 1AF7 6.3A
DANGER HIGH VOLTAGE |
All Fuses
230Vac Anti-surge
1 2 3 4 58 9 10 11 14 15 16 17 20 21 22 23
N L N L N L
34 35 36 376 7 12 13 18 19 24
L N
33 38
3940414344454647 424849505152
L L L L L N L L L L L N L L L L L N L L L L L N L L L L L N
Spare
Clock Stat Pump Clock Stat Pump Clock Stat Pump Clock Stat Pump Clock
Cyl
Stat Pump
Heating
Hot water
HMI
INOUT NC2 C2 NO2 NO1 C1 NC1 OP2 OP1
26 27 28 2925 30 31 32
Link
Motor HW
2-Port Zone Valve
- DHW -
ASHP Terminals
1
2
3
4
5
6
7
8
17
18
19
20
21
22
23
24
25
Hot Water (Yellow)
Common (Red)
Link Heating (Blue)
Aerona ³
Heat Pump
Motor HTG
2-Port Zone Valve
- Radiator Circuit -
Do not
connect
Motor HTG
2-Port Zone Valve
- UFH Circuit -
Do not
connect
Do not
connect
Do not
connect
Do not
connect
Do not
connect
ON
OFF
Digital
Dual Thermostat
L N C1
Additional Circulator
for UFH Circuit
L N E
Aerona³ Controller
UFH
Actuator
- Zone 1 -
Brown
Blue
L1 2 E N S/L
THERMOSTAT ZONE 1
1 2
L L N N
ACTUATORS
Or Gr L E N
UFH VALVE
Ls E Lr
HEAT
ENABLE
L E N
UFH PUMP
L E N
L L N N
ACTUATORS
ZONE 1 ZONE 2
L E N
MAINS SUPPLY TIME CLOCK
2E N S/L
THERMOSTAT ZONE 2
UFH
RAD
ZONE 8 TYPE
FUSE
5 Amp Anti-Surge
L1
L
N
A1A2RT1RT2 -
Link
Grant NeoStat
Programmable Room
Thermostat
- UFH Circuit -
Grant UH8 Wiring Centre
Zones
3 to 8
Zones
3 to 8
N L
Hot Water
Immersion
Heater
N L
LOAD
SUPPLY
N L
Greenbrook T205-C
Immersion Timer
(indepently switched and
fused at 13A)
5A
L N E
230V
50HZ
L
N
A1A2RT1RT2 -
Link
Grant NeoStat
Programmable Room
Thermostat
- Radiator Circuit -
CH1CH2CH3
CH4N L
Grant HPIDTM4
DHW Timer
Brown
Blue Orange
Grey
Orange
Grey
Orange
Grey
G/Y
G/Y
Brown
Blue
Brown
Blue
G/Y
Pre-wired in FactoryInstaller Wiring Installer Wiring
Grey
Black
Blue
Brown
Brown
Blue
G/Y
E N L
230V
50HZ

Section 6: Commissioning, Draining Down and Safety Page 19
! NOTE !
Commissioning details should be entered in the
commissioning and service log at the back of these
instructions.
6.1 FILLING THE CYLINDER
! CAUTION !
Before lling the cylinder check that the immersion heaters
have not loosened in transit. Tighten as necessary using
a shaped spanner. Stillsons or pipe grips should not be
used.
1. Ensure that all connections are fully tightened.
2. Ensure that the service valve in the cold water supply is
closed.
3. Open all hot water taps supplied by the cylinder.
4. Slowly open the service valve in the cold water supply.
5. Continue to ll the cylinder until water ows from all taps
6. Open the service valve fully and close all the hot taps.
7. Allow system to stabilise for ve minutes.
8. Open each hot water tap in turn to expel air from the system
pipe work.
9. Check for leaks.
10. Manually operate Temperature and Pressure Relief Valve
(refer to Figure 2-1), to ensure free water ow through
discharge pipe. (Turn knob to left).
11. Heat the water to chosen temperature and then close the
service valve.
12. Drain the cylinder to ush out any ux/solder from the
installation process. Refer to Section 6.2 below.
13. Re-ll the cylinder – as described above.
14. Re-heat cylinder to the required temperature and re-check for
leaks.
6.2 DRAINING DOWN
1. Switch o󰀨 the electrical power to the immersion heater
(important to avoid damage to the element).
2. Switch o󰀨 the heat pump (or boiler).
3. Turn o󰀨 the cold water service valve (or stop cock).
4. Open all hot water taps.
5. Open drain cock in cold water supply to drain unit down.
Refer to Figure 2-1.
6.3 IMMERSION HEATER SAFETY CUT-OUT
The immersion heater incorporates an independent non self-
resetting over temperature cut-out device to prevent excessive
water temperatures. Refer to Section 5.3 for further details.
The safety cut-out will operate if:
a. The wiring is incorrect.
b. The immersion heater thermostat or cylinder thermostat fails.
c. Thermostat is set too high.
To reset the safety cut-out:
1. Unscrew and remove the nut holding the immersion heater
cover in place.
2. Remove the immersion heater cover.
! WARNING !
Before removing the immersion heater cover, to either
reset the safety cut-out or check/alter the thermostat
setting, ensure that the electrical supply is isolated.
3. The safety cut-out reset pin is positioned to the side of the
control knob (indicated by a triangle with the word ‘safety’
below). Refer to Figure 5-1.
4. If the cut-out has operated, the reset pin will be pushed
upwards (to be level or slightly above the cover).
5. Wait until the temperature has fallen su󰀩ciently.
6. Investigate and identify the cause of the cut-out operation
and rectify the fault.
7. Press in the reset pin (to its normal operating position) to
reset the cut-out. Use hand pressure only with a suitably
sized implement.
8. Ret the immersion heater cover correctly and secure in
position with retaining nut.
9. Switch the mains electricity supply back on.
If the problem persists, please contact your installer.
6 COMMISSIONING, DRAINING DOWN AND SAFETY

Section 6: Commissioning, Draining Down and SafetyPage 20
6.4 COLD WATER DISCHARGE FROM
TUNDISH
There are two reasons why cold water will discharge from the
tundish:
1. The pressure reducing valve has malfunctioned (This will
cause a large volume of water to ow through the tundish).
2. The Expansion relief valve is letting by (This will cause a very
low volume of water to ow through the tundish).
In both cases, identify the defective component and replace. All
repairs must be carried out by a competent person.
6.5 HOT WATER DISCHARGE FROM TUNDISH
There are four reasons why hot water will discharge from the
tundish:
1. Thermal cut-out has malfunctioned.
2. The control thermostat has malfunctioned.
3. The T & P valve is letting by.
4. The expansion vessel has failed or lost its charge.
In all cases, should a repair be necessary, the work must be
carried out by a competent person.
Isolate the cylinder from all electrical supplies before commencing
maintenance work.
6.6 EXPANSION VESSEL
1. The expansion vessel is connected into the cold water supply
to the cylinder.
! NOTE !
No valve should be tted between the expansion vessel
and the supply pipe.
2. Ensure that the air charge in the vessel matches the
pressure setting shown on the pressure reducing valve.
3. The expansion vessel must be installed even if an
accumulator is tted.
4. The charge of the vessel must be checked at every annual
service.
6.7 CUSTOMER HANDOVER
1. Complete the commissioning and service log at the back of
these instructions and leave the instructions with the user.
2. Explain the operation of the system to the User, referring to
Section 12 of these instructions.
3. In particular, make the user aware of what to do if water is
seen to ow from either the T&P Valve or Expansion relief
Valve.
4. Refer the user to the Information given in Section 12 of these
instructions.
! NOTE !
Leave these Installation, Servicing and User instructions
with the user for future reference.