State Water Heaters SCE 80-115 Troubleshooting guide

Installation
User and
Service Manual
80-115
80-140
80-180
95-199
95-260
70-360
65-400
65-500
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your installer
www.state-waterheaters.co.uk

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Warning
Read this manual carefully before first using the water heater. Failure to read
this manual and to follow the instructions in this manual may lead to
accidents, personal injury, and damage to the appliance.
Copyright
Copyright 2004 State Water Heaters
All rights reserved.
Nothing from this publication may be copied, reproduced and/or published by
means of printing, photocopying or by whatsoever means, without the prior
written approval of State Water Heaters.
State Water Heaters reserves the right to modify specifications stated in this
manual.
Trademarks
Any brand names mentioned in this manual are registered trademarks of their
respective owners.
Liability
State Water Heaters accepts no liability for claims from third parties arising from
improper use other than that stated in this manual and in accordance with the
General Conditions registered at the Eindhoven Chamber of Commerce.
Refer further to the General Conditions. These are available on request, and
without charge.
Although considerable care has been taken to ensure a correct and suitably
comprehensive description of all relevant components, the manual may
nonetheless contain errors and inaccuracies.
Should you detect any errors or inaccuracies in the manual, we would be
grateful to receive notification. This helps us to further improve our
documentation.
More information
If you have any comments or queries concerning any aspect related to the
appliance, then please do not hesitate to contact State Water Heaters.
Aquaheat State Sales
Orchard House, 61-67 Commercial Road
Southampton SO15 1GG
Tel.: [phone]
Fax: [phone]
E-mail: [e-mail]
In the event of problems with connecting to the gas, electricity or water supply,
please contact your installation’s supplier/installer.

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Table of contents
1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
1.1 About the appliance - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
1.2 What to do if you smell gas- - - - - - - - - - - - - - - - - - - - - - - - - 9
1.3 Regulations - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9
1.4 Target groups - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10
1.5 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 10
1.6 Forms of notation - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11
1.7 Overview of this document - - - - - - - - - - - - - - - - - - - - - - - - 11
2 Functioning of the appliance - - - - - - - - - - - - - - - - - - 13
2.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 13
2.2 Functional description of the appliance - - - - - - - - - - - - - - - - - - 14
2.3 The appliance’s heating cycle - - - - - - - - - - - - - - - - - - - - - - 15
2.4 Protection for the appliance - - - - - - - - - - - - - - - - - - - - - - - 15
2.4.1 Water temperature protection - - - - - - - - - - - - - - - - - 16
2.4.2 Flue gas backflow safeguard - - - - - - - - - - - - - - - - - 16
2.4.3 Ionisation rod - - - - - - - - - - - - - - - - - - - - - - - - - 16
2.5 Safety of the installation - - - - - - - - - - - - - - - - - - - - - - - - - 16
2.5.1 Unvented installation - - - - - - - - - - - - - - - - - - - - - 16
2.5.2 Vented installation- - - - - - - - - - - - - - - - - - - - - - - 17
2.5.3 T&P valve - - - - - - - - - - - - - - - - - - - - - - - - - - - 17
3 Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - 19
3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 19
3.2 Packaging - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21
3.3 Environmental conditions- - - - - - - - - - - - - - - - - - - - - - - - - 21
3.3.1 Working clearances - - - - - - - - - - - - - - - - - - - - - - 21
3.3.2 Humidity and ambient temperature- - - - - - - - - - - - - - - 21
3.3.3 Maximum floor loading - - - - - - - - - - - - - - - - - - - - 22
3.3.4 Water composition - - - - - - - - - - - - - - - - - - - - - - 22
3.4 Technical specifications - - - - - - - - - - - - - - - - - - - - - - - - - 22
3.5 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 24
3.6 Water connections, Unvented - - - - - - - - - - - - - - - - - - - - - - 26
3.6.1 Cold water side - - - - - - - - - - - - - - - - - - - - - - - - 26
3.6.2 Shunt pipe - - - - - - - - - - - - - - - - - - - - - - - - - - 26
3.6.3 Hot water side - - - - - - - - - - - - - - - - - - - - - - - - - 26
3.6.4 Drain valve - - - - - - - - - - - - - - - - - - - - - - - - - - 26
3.6.5 Circulation pipe - - - - - - - - - - - - - - - - - - - - - - - - 27
3.7 Water connections, Vented- - - - - - - - - - - - - - - - - - - - - - - - 27
3.7.1 Cold water side - - - - - - - - - - - - - - - - - - - - - - - - 27
3.7.2 Shunt pipe - - - - - - - - - - - - - - - - - - - - - - - - - - 27
3.7.3 Hot water side - - - - - - - - - - - - - - - - - - - - - - - - - 27
3.7.4 Circulation pipe - - - - - - - - - - - - - - - - - - - - - - - - 27
3.8 Gas connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 28
3.9 Flue gas discharge- - - - - - - - - - - - - - - - - - - - - - - - - - - - 28
3.9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 29
3.9.2 Fitting the draught diverter - - - - - - - - - - - - - - - - - - - 29
3.9.3 Flue gas thermostat assembly - - - - - - - - - - - - - - - - - 30
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3.10 Electrical connection - - - - - - - - - - - - - - - - - - - - - - - - - - - 31
3.10.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 31
3.10.2 Preparation- - - - - - - - - - - - - - - - - - - - - - - - - - - 31
3.10.3 Mains voltage - - - - - - - - - - - - - - - - - - - - - - - - - 32
3.10.4 Week timer circuit - - - - - - - - - - - - - - - - - - - - - - - 33
3.10.5 Connecting extra error signal (’Alarm OUT’) - - - - - - - - - - - 33
3.11 Checking the supply pressure and burner pressure - - - - - - - - - - - - 33
3.12 Conversion to a different gas category - - - - - - - - - - - - - - - - - - - 36
3.12.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 36
3.12.2 Conversion to a different gas SCE 80-115 through 65-400- - - - 37
3.12.3 Conversion to a different gas category SCE 65-500 - - - - - - - 39
4 Filling and draining - - - - - - - - - - - - - - - - - - - - - - - 43
4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 43
4.2 Filling the appliance - - - - - - - - - - - - - - - - - - - - - - - - - - - - 44
4.2.1 Filling unvented installations - - - - - - - - - - - - - - - - - - 44
4.2.2 Filling vented installations- - - - - - - - - - - - - - - - - - - - 44
4.3 Draining the appliance - - - - - - - - - - - - - - - - - - - - - - - - - - 44
4.3.1 Draining unvented installations - - - - - - - - - - - - - - - - - 44
4.3.2 Draining vented installations - - - - - - - - - - - - - - - - - - 45
5 Operating - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
5.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
5.2 Control panel - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47
5.3 Explanation of the icons - - - - - - - - - - - - - - - - - - - - - - - - - - 48
5.4 I/0/II switch - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48
5.5 Control thermostat - - - - - - - - - - - - - - - - - - - - - - - - - - - - 48
5.6 Burner control reset button - - - - - - - - - - - - - - - - - - - - - - - - 49
5.7 Week timer circuit - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49
5.8 Flue gas backflow safeguard reset button - - - - - - - - - - - - - - - - - 50
6 Status of the appliance - - - - - - - - - - - - - - - - - - - - - 51
6.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
6.2 Operating modes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
6.3 Power Anode Status - - - - - - - - - - - - - - - - - - - - - - - - - - - 51
6.4 Error conditions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 52
7 Starting up and shutting down - - - - - - - - - - - - - - - - - 53
7.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 53
7.2 Starting up - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 53
7.3 Shutting down- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 53
7.3.1 Shut the appliance down for a brief period (’OFF mode’)- - - - - 53
7.3.2 Disconnect the appliance from the mains - - - - - - - - - - - - 53
7.3.3 Shut the appliance down for a longer period- - - - - - - - - - - 53
7.4 The appliance’s heating cycle - - - - - - - - - - - - - - - - - - - - - - - 54
8 Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - 55
8.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 55
8.2 Troubleshooting table for general errors - - - - - - - - - - - - - - - - - - 56
8.3 Troubleshooting table ’no hot water’ - - - - - - - - - - - - - - - - - - - - 57
8.4 Troubleshooting table ’insufficient hot water’ - - - - - - - - - - - - - - - - 60
9 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 61
9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 61

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9.2 Preparation for maintenance - - - - - - - - - - - - - - - - - - - - - - - 61
9.3 Water-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - 62
9.3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 62
9.3.2 Checking the anodes - - - - - - - - - - - - - - - - - - - - - 62
9.3.3 Descaling and cleaning the tank - - - - - - - - - - - - - - - - 62
9.4 Gas-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 63
9.4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 63
9.4.2 Cleaning the burners - - - - - - - - - - - - - - - - - - - - - 63
9.4.3 Cleaning the orifices- - - - - - - - - - - - - - - - - - - - - - 63
9.4.4 Checking the flue baffles - - - - - - - - - - - - - - - - - - - 63
9.5 Finalising maintenance- - - - - - - - - - - - - - - - - - - - - - - - - - 63
10 Warranty (Certificate)- - - - - - - - - - - - - - - - - - - - - - 65
10.1 General warranty - - - - - - - - - - - - - - - - - - - - - - - - - - - - 65
10.2 Tank warranty - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 65
10.3 Installation and conditions of use - - - - - - - - - - - - - - - - - - - - - 65
10.4 Exclusions - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 66
10.5 Scope of the warranty - - - - - - - - - - - - - - - - - - - - - - - - - - 66
10.6 Claims - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 66
10.7 Limitation of liability State - - - - - - - - - - - - - - - - - - - - - - - - 66
A Appendices- - - - - - - - - - - - - - - - - - - - - - - - - - - 67
A.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 67
A.2 Electrical diagram SCE- - - - - - - - - - - - - - - - - - - - - - - - - - 68
A.2.1 Electrical diagram SCE 65-500 LP - - - - - - - - - - - - - - - 68
A.2.2 Electrical diagram SCE - - - - - - - - - - - - - - - - - - - - 69
IX Index - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 71

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About the appliance
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1 Introduction
1.1 About the appliance This manual describes how to install, service and use the SCE appliance. The
SCE appliance is a gas-fired open water heater without a fan. The SCE
appliance is fitted with a flue gas backflow safeguard and falls into the appliance
category B11BS. This information is located on the appliance’s identification
plate. The information in this manual is applicable to types SCE: 80-115,
80-140, 80-180, 95-199, 95-260, 70-360, 65-400, 65-500.
The manner of construction and features of the appliance are in conformance
with the European standard for gas-fired storage water heaters for the
production of domestic hot water (ES 89). The appliances are therefore
compliant with the European Directive for Gas Appliances, and have the right to
bear the CE mark.
Warning
Read this manual carefully before starting up the water heater. Failure to
read the manual and to follow the printed instructions may lead to personal
injury and damage to the appliance.
1.2 What to do if you
smell gas Warning
Whenever there is a smell of gas:
No naked flames! No smoking!
Avoid causing sparks! Do not use any electrical equipment or switch, i.e. no
telephones, plugs or bells!
Shut off the mains gas supply!
Open windows and doors!
Warn occupants and leave the building!
After leaving the building, alert the gas distribution company or installer.
1.3 Regulations As the (end) user, installer or service and maintenance engineer, you must
ensure that the entire installation complies, as a minimum, with the official local:
• building regulations;
• energy supplier’s directives for existing gas installations;
• directives and technical guidelines for natural gas installations;
• safety requirements for low-voltage installations;
• regulations governing the supply of drinking water;
• regulations governing ventilation in buildings;
• regulations governing the supply of air for combustion;
• regulations governing the discharge of products of combustion;
• requirements for installations that consume gas;
• regulations governing indoor waste water disposal;
• regulations imposed by fire service, power companies and municipality;
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Introduction
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Furthermore, the installation must comply with the manufacturer’s instructions.
nNote
Later amendments and/or additions to all regulations, requirements and
guidelines published on or prior to the moment of installing, will apply to the
installation.
1.4 Target groups The three target groups for this manual are:
• (end) users;
•installers;
• service and maintenance engineers.
Symbols on each page indicate the target groups for whom the information is
intended. See Table 1.1.
1.5 Maintenance A service should be carried out at least once a year, both on the water side and
on the gas side. Maintenance frequency depends, among other things, on the
water quality, the average burning time per day and the set water temperature.
nNote
To determine the correct maintenance frequency, it is recommended to
arrange for the service and maintenance engineer to check the appliance on
both the water and gas side, three months after installation. Based on this
check, the best maintenance frequency can be determined.
nNote
Regular maintenance extends the service life of the appliance.
Both the end user and the service and maintenance engineer are responsible
for regular maintenance. They will need to establish clear agreements on this.
nNote
If the appliance is not regularly maintained, the warranty will become void.
Table 1.1 Target group symbols
Symbol Target group
g(End) user
iinstaller
sService and maintenance engineer

Forms of notation
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1.6 Forms of notation The following notation is used in this manual:
nNote
Important information
cCaution
Ignoring this information can lead to the appliance being damaged.
Warning
Failure to carefully read this information may lead to danger of personal
injury, and serious damage to the appliance.
1.7 Overview of this
document
Tab l e 1.2 provides an overview of the contents of this document.
Table 1.2 Contents of document
Chapter Target groups Description
2 Functioning of the
appliance gis This chapter describes how the appliance functions.
3 Installation is This chapter describes the installation activity to be completed
before you actually start up the appliance. Instructions are
also provided for the installation and/or service and
maintenance engineer on converting the appliance to other
types of gas.
4 Filling and draining gis This chapter describes how to fill and drain the appliance.
5 Operating gis This chapter describes the appliance’s control panel, and how
to use it.
6 Status of the appliance gis This chapter describes the status (mode or condition) that the
appliance may have, and possible actions to take.
7 Starting up and shutting
down gis This chapter describes how to start up the appliance, and how
to shut it down for a brief or long period of time. The general
heating cycle of the appliance is also described.
8 Troubleshooting gis This chapter is mainly intended for the installer and the service
and maintenance engineer. It describes appliance errors.
These errors are indicated on the display. A troubleshooting
table of possible causes and solutions is provided. End users
may also refer to this chapter for additional information about
the appliance.
9 Maintenance sThis chapter sets out the maintenance tasks to be carried out
during a service.
10 Warranty (Certificate) gis This chapter states the warranty terms and conditions.

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Introduction
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2 Functioning of the
appliance
2.1 Introduction Topics covered in this chapter:
•Functional description of the appliance;
•The appliance’s heating cycle;
•Protection for the appliance;
•Safety of the installation.
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2.2 Functional
description of the
appliance
Figure 2.1 shows a cut-away view of the appliance.
In this appliance, the cold water enters the bottom of the tank via the cold water
inlet z. The heat of combustion is transferred to the water through the
combustion chamber jand flue tubes d. The heated tap water leaves the tank
via the hot water outlet o. Once the appliance is completely filled with water, it
remains constantly under water supply pressure. As hot water from the
appliance is consumed, it is continuously replenished with cold water.
Legend
aflue gas discharge
bdraught diverter
canodes
dflue tubes
eflue baffles
fPU-isolation
gtank
hcleaning opening
idrain valve
jcombustion chamber
kradiation shield/condensation
tray
lgas control
mflue gas thermostat sensor
nflue gas thermostat
ohot water outlet
psafety thermostat sensor
qhigh-limit thermostat sensor
rcontrol panel
scontrol thermostat
tburner control
uhigh-limit thermostat
vfrost thermostat
wsafety thermostat
xcontrol thermostat sensor
yfrost thermostat sensor
zcold water inlet
Aglow igniter
Bionisation rod
Cbar burner/ burner tray
Figure 2.1 Cross-section of the appliance
IMD-0143
m
n
o
p
u
x
z
A
C
q
t
w
r
s
v
y
B
a
c
d
e
f
h
i
j
k
g
b
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The appliance’s heating cycle
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The gas required for combustion flows into the manifold via the gas control l.
Orifices are located within the manifold. Via these orifices, the gas enters the
bar burners C. The bar burners together form the burner tray. As the gas is
injected into the bar burners, the primary air required for combustion is also
drawn in(1). Additional air is drawn through the openings in the burner tray. The
glow igniter Aensures the ignition of the gas/air mixture. The flue gases
generated by this combustion are led through the flue tubes d. There are flue
baffles efitted inside the flue tubes. These slow down the flue gas exhaust,
improving the heat transfer efficiency. The flue gases leave the appliance via the
draught diverter b. A radiation shield/condensation tray kis mounted below
the burner tray. This prevents overheating of the floor surface under the
appliance and serves as a collection tray for condensation water.
The PU-isolation fprevents heat loss. The inside of the tank is enamelled to
protect against corrosion. The anodes cprovide additional protection. The
Hydro Cannon also protects the bottom of the tank from scale and lime buildup.
2.3 The appliance’s
heating cycle
The entire appliance is controlled by the burner control tand the control
thermostat sor frost thermostat v. The control thermostat and frost thermostat
both independently measure the water temperature (Twater). The appliance’s
heating cycle is activated as soon as Twater falls below the specified threshold
value (Tset). The value for Tset depends on the status chosen for the appliance,
see paragraph ’6.2 Operating modes’. If the appliance is in the ’OFF mode’
(frost protection), then this value is determined by the frost thermostat
(threshold value = 20°C). If the appliance is in the ’ON mode’, then the threshold
value is selectable via the control thermostat (±40°C - ±70°C).
As soon as Twater falls below Tset, the relevant thermostat (control or frost) will
close, and the burner control will register a heat demand. The gas control lwill
open, and the gas will mix with the air it draws in. This mixture is ignited by the
glow igniter Aand the water becomes heated. A soon as Twater exceeds Tset,
the thermostat will open once more. The heat demand will cease, and the
burner control will stop the heating cycle.
The thermostats have a certain margin both when closing and opening. We refer
to this margin as the hysteresis. The hysteresis cannot be adjusted.
2.4 Protection for the
appliance
The burner control monitors the water temperature by means of thermostats,
and ensures a safe combustion. This is achieved by:
•theWater temperature protection;
•theFlue gas backflow safeguard;
•theIonisation rod.
1. The narrow opening in the orifices accelerates the gas flow. This causes a partial vacuum. The
effect of this partial vacuum is to draw the air into the flow (the Venturi effect).

Functioning of the appliance
16 Instruction Manual SCE
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2.4.1 Water temperature protection
By means of the frost, high-limit and safety thermostats, the burner control
monitors three temperatures related to safety. See Tab le 2. 1 .
2.4.2 Flue gas backflow safeguard
The flue gasses are directed to the outside via the draught diverter band the
flue gas discharge a. To prevent the flue gases from flowing back into the boiler
room, the discharge ducting is monitored by a feature called the Thermal Reflux
Safeguard (T.R.S.). This uses a flue gas thermostat sensor mwith flue gas
thermostat nwhich are located in the draught diverter. Under normal
circumstances this sensor will register the ambient temperature. However, if the
chimney is not drawing sufficiently (for example, due to a blockage in the
chimney), the flue gases will ’reflux’ and flow back past the flue gas thermostat
sensor. The sensor will then detect an excessive temperature and the flue gas
thermostat will open. The heat demand will be ended, and the burner control
immediately stops the heating cycle. The flue gas thermostat will also lock out.
This must be manually reset, before the appliance can be put back into
operation.
2.4.3 Ionisation rod
To prevent gas flowing when there is no combustion, an ionisation rod Bis
fitted. The burner control uses this rod for flame detection, by means of
ionisation detection. The burner control acts immediately, as soon as it detects
that gas is flowing, but there is no flame.
2.5 Safety of the
installation
In addition to the standard safety monitoring of the appliance, the appliance
must also be protected by an expansion vessel, pressure overflow valve, non-
return valve and a T&P valve.
Use of an expansion vessel, a pressure relief valve and/or a pressure reducing
valve depends on the type of installation: unvented or vented.
2.5.1 Unvented installation
With an unvented installation, a pressure relief valve and expansion vessel
prevent excessive pressure in the tank. This prevents damage being caused to
the enamelled coating (in the appliance) or to the tank. A non-return valve
prevents excessive pressure in the water supply system. This valve also
Table 2.1 Temperature protection
Protection Description
Frost thermostat If the frost thermostat sensor ydetects a temperature of 20°C or lower, the
appliance’s heating cycle will start. See paragraph ’2.3 The appliance’s
heating cycle’.
High-limit thermostat If the high-limit thermostat sensor qdetects a temperature greater than 84°C,
the high-limit thermostat will open. The heat demand will be stopped, and the
burner control will stop the heating cycle until the high-limit thermostat closes
again. At that moment, the burner control resets the appliance, and the heating
cycle resumes. The high-limit safeguard serves to prevent overheating and/or
excessive formation of scale in the appliance.
Safety thermostat If the safety thermostat sensor pdetects a temperature greater than 93°C, the
safety thermostat will open. The heat demand will be ended, and the burner
control immediately stops the heating cycle. A lockout error will occur in the
burner control. This must be manually reset, before the appliance can be put
back into operation.

Safety of the installation
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prevents water from flowing backwards from the tank into the cold water supply
system. The pressure reducing valve protects the installation against an
excessively high water supply pressure (> 8 bar). These components are fitted
to the cold water pipe. See paragraph ’3.6.1 Cold water side’.
2.5.2 Vented installation
With a vented installation, excess pressure is taken up by the open water
reservoir. The level of the water reservoir determines the maximum working
pressure in the tank, which may not exceed 8 bar. The installation must also be
fitted with an overflow from the hot water pipe, which discharges into the water
reservoir. See paragraph ’3.6.3 Hot water side’.
2.5.3 T&P valve
A T&P valve is only mandatory in an ’unvented’ installation. However, State also
recommends the use of a T&P valve in ’vented’ installations.
A T&P valve monitors the pressure in the tank, and the water temperature at the
top of the tank. If the pressure in the tank becomes excessive (>10 bar) or the
water temperature is too high (>97°C), the valve will open. The hot water will
immediately flow out of the tank. Because the appliance is under water supply
pressure, cold water will automatically flow into the tank. The valve remains
open until the unsafe situation has been averted. A connecting point for a T&P
valve is standard on the appliance. See paragraph ’3.6.3 Hot water side’.

Functioning of the appliance
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Introduction
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3 Installation
Warning
The installation should be carried out by an approved installer in compliance
with the general and local regulations imposed by the gas, water and power
supply companies and the fire service.
The appliance may only be installed in a room which complies with the
requirements stated in national and local ventilation regulations.
Refer also to paragraph ’1.3 Regulations’.
3.1 Introduction This chapter describes the installation activities to be carried out before the
appliance may be started up, namely:
•Packaging;
•Environmental conditions;
•Technical specifications;
•Water connections, Unvented;
•Water connections, Vented;
•Gas connection;
•Flue gas discharge;
•Electrical connection;
•Checking the supply pressure and burner pressure;
•Conversion to a different gas category;
nNote
Starting up the appliance is described in chapter ’7 Starting up and shutting
down’.
Figure 3.1 shows a front view of the appliance.
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Installation
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Figure 3.1 Plan and elevation of the appliance
IMD-0145