Trianco Aztec Gold User manual

TRIANCO
KM 59690
Electric System Boiler
To be retained by the householder
FITTING, OPERATION,
INSTALLATION & SERVICING
INSTRUCTIONS

2
Notes:
(a) Electrical safety checks should be carried out by a competent person.
(b) It is a requirement of the guarantee and any extended warranty that an annual service is carried out by a competent
person.
Installation Engineer’s Signature ................................................................................................................................
Company Name (if applicable) ................................................................................................................................
Company Address: ................................................................................................................................
................................................................................................................................
................................................................................................................................
Company Tel. No: ................................................................................................................................
HEALTH AND SAFETY
INFORMATION FOR THE INSTALLER AND SERVICE ENGINEERS
Under the Consumer Protection Act 1987 and the Health and Safety at Work Act 1974, it is a
requirement to provide information on substances hazardous to health (COSHH Regulations
1988).
The Company takes every reasonable care to ensure that these products are designed and
constructed to meet these general safety requirements, when properly used and installed.
To fulfil this requirement products are comprehensively tested and examined before despatch.
This appliance may contain some of the items below.
When working on the appliance it is the responsibility of the user/engineer to ensure that any
necessary personal protective clothing or equipment is worn appropriate to parts that could be
considered as being hazardous to health and safety.
INSULATION AND SEALS
Mineral fibre insulation is used on this appliance.
May be harmful if inhaled. May be irritating to the skin, eyes, nose or throat. When handling avoid
inhalation and contact with eyes. Use (disposable) gloves, face masks and eye protection.
After handling wash hands and other exposed parts. When disposing, reduce dust with water
spray, ensure parts are securely wrapped.
GLUES, SEALANTS & PAINT
Glues and sealants are used in the product and present no known hazards when used in the
manner for which they are intended.
PACKAGING
Materials used for the packaging of this appliance are of a recyclable nature.
Warning: plastic bags can cause suffocation. Keep out of reach of children.

Please read these instructions fully before installing this appliance.
If in doubt, seek expert advice.
These instructions should be kept in a place close to the appliance for easy reference.
CONTENTS
BASIC FITTING INSTRUCTIONS 4
Preparation and Siting 4/5
Ventilation 4
Clearances and Access 4
Water System 6
Electrical Supply 6
Wiring Diagrams 6/7
Filling the System 8/9
Underfloor Heating Systems 10
OPERATING INSTRUCTIONS 11
Introduction 11
Boiler Controls 11
Indicator Lights 11
Safety Controls 11
External Controls 11
Cleaning & Maintenance 11
Simple Fault-Finding 12
TECHNICAL SPECIFICATION 12
INSTALLATION NOTES 13
Regulations & Safety 13
Declaration of Conformity 13
Boiler Schematic 14
Boiler Components 15
SERVICE 16
After-Sales Service Information 16
Engineer's Fault-Finding 17
Servicing 18
Parts Replacement 18/19/20
Spares List 21

4
PREPARATION & SITING
1) Before starting the installation, carefully unpack the
boiler from the carton, ensuring all items are present
and in good condition. The carton should include:
1 x fully-cased boiler
2 x cable strain reliefs
1 x hose connector with manifold fitting
1 x high-limit thermostat for underfloor heating
Notes: Always store the boiler in a dry place prior to
fitting.
Retain all packaging until installation is complete.
Plastic bags can cause suffocation; please keep
out of reach of children.
2) Work out the desired position of the boiler and, using
the dimensions on Fig. 2 for reference, drill 4 x 6mm
holes in the wall to a depth of 38mm. Insert wall plugs
and fixing screws (not supplied) into the wall.
Notes:
a) If the appliance is to be fitted in a confined space or
compartment with a potential ambient temperature of
60°C or above, it is strongly recommended that
adequate ventilation is provided to prevent the
overheating of the boiler controls. Aeration of 110cm2
will be required to the compartment, in both high and
low level positions.
b) Ensure that the area surrounding the boiler is kept free
of items which would impede the good ventilation of
the appliance (e.g. towels, linen).
c) When siting the boiler, take into account the need for
future servicing. Enough space should be provided at
the front of the appliance to enable an engineer to
adequately service and/or replace components.
d) The boiler is not to be fitted in a shower compartment
or bathroom, and is not suitable for external installation,
nor in any area subject to adverse temperature
conditions or moisture.
e) The appliance is designed to be fitted in an upright
position only, with the flow and return connections to
the bottom of the boiler.
f) Ensure adequate clearance is allowed for making the
water connections, as the boiler can be fully serviced
from the front.
FITTING INSTRUCTIONS
The Aztec Gold is a wall-mounted electric central heating boiler designed with smaller locations in mind. The boiler can be fitted
in the smallest of places and requires minimal attention to ensure efficient and reliable operation. The boiler produces hot water
for a fully-sealed system by passing water over electric heating elements which are housed in an insulated stainless steel heat
exchanger.
FIG. 1 - PACK CONTENTS
FIG. 2 - DIMENSIONS & CLEARANCES

FITTING INSTRUCTIONS (cont.)
3) Removing the front panel beforehand, hang the
boiler onto the screws in the wall, ensuring that all
4 keyhole fixing slots are utilised. Tighten screws
to ensure a secure fixing.
4) Fit the 2 x cable strain reliefs into the base of the
boiler.
5) Install the heating system (radiator/towel rails, etc)
in the desired positions as per the manufacturer's
instructions. A drain cock must be fitted at the
lowest part of the system for ease of drainage.
See Fig. 4 for a typical system layout.
IMPORTANT
While the Aztec Gold is entirely suitable for use on
heating systems which utilise plastic pipework, the
first 100mm from the boiler manifold must always
be 15mm copper.
5
FIG. 3 - STRAIN RELIEF FIXING

FITTING INSTRUCTIONS (cont.)
WATER SYSTEM
Connect the flow and return pipework from the
radiator(s) into the corresponding fittings on the boiler
manifold. Ensure all fittings are made water-tight.
Notes:
a) The pressure relief valve must be piped to a
permanent drain-off on the outside of the
building. The drain must not discharge above
an entrance, window, or any public access
area. It should be clear of any electrical
fittings, and positioned so that any discharge
can be clearly seen. The terminating point of
the drain-off should be bent down at an angle
of 90°.
b) It is recommended that isolation valves are
fitted to the pipework. A bypass, as shown in
Fig. 4, must be fitted if TRVs are used on the
radiators.
c) The flow and return connections are made to
the boiler by 2 x 15mm compression fittings.
ELECTRICITY SUPPLY
First isolating the electricity, pass the electrical supply
cables and any external control cables through the
cable strain reliefs in the base of the boiler, and wire
securely into the terminal block. The terminal block is
located within the casings at the top left-hand side of
the boiler.
Notes:
a) This appliance must be earthed.
b) It is recommended the boiler is fitted with an
external control, such as a room thermostat
or programmer.
c) If the water in the system is to be subject to
freezing conditions during the pipework run,
the appliance should be fitted with a frost
thermostat. This will activate the boiler should
the temperature fall to a level which could
damage the installation.
d) Incoming mains and controls cables should
not be routed close to heating pipes.
e) The diagrams opposite are for reference only.
Refer to manufacturer's instructions for
specific fitting instructions for the room
thermostat or programmer.
f) It is recommended that the boiler is wired via
a 13 amp RCD plug or switched fused spur.
g) Remove the link wire between terminals 3 &
5 when fitting any external controls.
6
FIG. 5 - BOILER CONNECTION MANIFOLD, SHOWING
PRESSURE RELIEF VALVE, WATER CONNECTIONS AND
PRESSURE GAUGE
FIG. 6 - WIRING FOR EXTERNAL PROGRAMMER & ROOM
THERMOSTAT
Important Note:
Before installation, please ensure that the supply
voltage to the appliance is above 207v. If the voltage
drops below this level, a temporary boiler malfunction
may result.

FITTING INSTRUCTIONS (cont.)
ELECTRICAL SUPPLY (cont.)
7
FIG. 9 - INTERNAL WIRING DIAGRAMFIG. 9 - INTERNAL WIRING DIAGRAM
FIG. 7 - WIRING FOR PROGRAMMABLE ROOM
THERMOSTAT
FIG. 8 - WIRING FOR EXTERNAL PROGRAMMER, ROOM
THERMOSTAT & FROST THERMOSTAT

FITTING INSTRUCTIONS (cont.)
FILLING THE SYSTEM
A filling point connection is provided on the front face of
the boiler manifold to facilitate the initial filling and
pressurising of the system via a hose connection
(supplied). Alternatively, a permanent filling-loop may be
employed.
Notes:
a) Before filling, ensure that all fittings and joints
have been made.
b) Thoroughly flush out the system to remove any
swarf and residue from the pipework and
radiator(s).
c) There must be no permanent connection between
the boiler and the mains water supply.
Filling Method 1: Temporary Hose (Figs. 10/11)
1) Connect a hose to the fill point on the manifold
using the fittings supplied.
2) Connect the other end of the hose to the mains
water supply, ensuring that all safety valves are
fitted in the run (Fig. 11) to prevent system
water entering the mains supply. Approved hose
unions should be used on all connections.
3) Open the fill point on the manifold (Fig. 10) by
turning the isolating knob anti-clockwise.
4) Ensure all isolation valves to the system are open,
that the bypass valve is closed, and that the
automatic air vent contained within the boiler
casings is open (turn the black cap on the device
fully anti-clockwise).
5) Switch on the mains supply to the boiler and test
the pressure relief valve by continuing to fill until
this device activates and releases water into the
drain.
6) Switch off the mains water supply.
7) Using the pressure gauge on the front face of the
manifold for reference, reduce the water content of
the system until the pressure is indicated as 1.5
bar.
8) Thoroughly vent all parts of the system of air and,
if necessary, readjust pressure back to 1.5 bar.
9) Close off the fill connection on the manifold, remove
the hose and close the automatic air vent.
10) Check all joints are water-tight before operating
the appliance.
8
FIG. 10 - FILL POINT
FIG. 11 - FILLING METHOD 1

FITTING INSTRUCTIONS (cont.)
Filling Method 2: Filling Loop (Fig. 12)
1) During installation, feed a permanent 15mm
supply to any part of the system via the use of a
WRC-approved filling loop. A fixed-spindle stop
valve should also be fitted to the mains water
supply to the system.
2) Open the supply valves to fill the system, following
all further instructions as per those for filling with a
hose from (4) onwards (page 8).
3) Once complete, close all supply valves.
Notes:
a) The filling method adopted must be in accordance
with the Water Supply Regulations and the Water
Bylaws.
b) Approved hose unions should be used on all
connections of this type.
COMPLETION
1) Replace the front casing of the boiler.
2) Switch on the electricity supply to the boiler and
external controls.
The appliance is now ready for use (Fig. 13).
See overleaf for additional fitting instructions when
using the boiler in conjunction with underfloor heating
systems.
9
FIG. 12 - FILLING METHOD 2
FIG. 13 - COMPLETED INSTALLATION

FIG. 14 - CONTROL KNOB
When installed on an underfloor heating system without
the use of a mixing valve, the following instructions must
be adhered to.
IMPORTANT NOTE: Ensure the mains supply to the
boiler is disconnected before carrying out any work.
1) Replace the safety high-limit thermostat with the
alternative stat provided within the literature pack
(Fig. 15). See page 19 for more detailed
instructions on how to replace high-limit thermostat.
2) Using the white control knob on the front of the
PCB controller, the temperature must be set to its
lowest setting (30°C) before initial firing.
Important: The temperature should only be
subsequently increased in accordance with
underfloor heating manufacturer's instructions and
BS EN 1264-4.
3) After the temperature has been adjusted to the
preferred level, it may be useful to remove the
control knob from the PCB controller to prevent
further modification. Carefully pull the knob from
the PCB, ensuring its mooring is held securely in
position (Fig. 14).
Notes:
a) The factory-fitted safety high-limit thermostat is set
at 100°C, and is suitable for use with radiator
heating systems. The additional high-limit
thermostat, for exclusive use with underfloor
heating systems, is set at 60°C and must be
fitted. Failure to do so will result in damage to
the floor surfaces.
b) If the high-limit thermostat operates often, the
temperature may be set too high. It is essential
that the temperature is not set to above 50°C
(refer to Fig. 14 for temperature settings).
c) The pump fitted to this appliance is suitable for a
Ø15mm plastic pipework run of up to 100m in
length. Pipework runs greater than this will require
the fitting of an additional pump.
d) Fit the underfloor heating system in accordance
with manufacturer's instructions. Trianco cannot
accept any responsibility for breakdowns or
damage caused by incorrectly-fitted systems.
10
CONTROL KNOB SETTINGS
FIG. 15 HIGH LIMIT THERMOSTAT REPLACEMENT
1 - ISOLATE ELECTRICAL SUPPLY
2 - REMOVE THE BOILER FRONT CASING
3 - REMOVE CABLES FROM HIGH LIMIT STAT
4 - LOOSEN 2 X RETAINING CLIPS
5 - REMOVE THERMOSTAT & REPLACE IN REVERSE
ORDER
ADDITIONAL FITTING INSTRUCTIONS - UNDERFLOOR HEATING SYSTEMS

OPERATING INSTRUCTIONS
The Trianco Aztec Gold boiler has been designed and
constructed to give years of trouble-free service and these
instructions are provided to assist you in obtaining the best
performance with the least trouble and cost.
The boiler is fully automatic in operation and requires little
attention, other than the setting of any external system
controls such as a room thermostat or programmer.
BOILER CONTROLS
Before initial firing of the boiler, ensure that the system is full
of water and the isolation valves (other than the bypass) are
fully open. Do not attempt to switch on the boiler if there
is any possibility that the system water is frozen.
1) Check that the time-switch/programmer is ON and
that the room thermostat is calling for heat.
2) Switch on the electrical supply to the boiler. After a
few seconds the green light should illuminate,
followed by the amber light.
3) Set the time-switch/programmer to the times and
programme required.
The boiler should now operate automatically, cutting in and
out according to demand.
To switch off the boiler, set the time-switch/programmer to the
OFF position. It is recommended that if the boiler is to be left
idle for a long period of time, the mains supply should also
be switched off.
BOILER INDICATOR LIGHTS (Fig. 16)
There are four indicator lights on the boiler. Left-to-right,
these are:
Green - the boiler is switched on
Amber - illuminated: boiler is running
- flashing: heat requirement is
satisfied
1st Red - a fault has occurred. See page 12.
2nd Red - the system pressure has dropped
below 1 bar. See page 12.
SAFETY CONTROLS
High-limit Thermostat
The boiler is fitted with an in-built safety thermostat which will
cause the appliance to shut down should the boiler
thermostat malfunction and the boiler overheat.
Note: Should the appliance be used for supplying
underfloor heating, this thermostat must be
replaced by the secondary stat supplied within the
literature bag.
EXTERNAL CONTROLS
Room Thermostat
The room thermostat should not be positioned close to a
source of heat, such as a radiator, or exposed to the sun, as
this would cause the heating to switch off before the room is
up to temperature. Always follow manufacturer's instructions
for best siting position for the thermostat.
Time-switch/Programmer
When choosing the operating times for your boiler, it is useful
to remember that central heating usually takes between half
an hour to an hour before it becomes effective. It is also
worth noting that the heating system will usually remain
effective for up to half an hour after boiler shutdown. The
timer can therefore be set to switch the appliance off earlier
as an economy measure.
Frost Thermostat
If the system is not in operation for many hours during very
cold weather, the water may be in danger of freezing. As
such, it is advisable that the installation is protected with a
frost thermostat.
Where the system is not protected, the boiler should be left
switched on and the room thermostat set to a low setting
(e.g. 7°C) to prevent the water temperature falling too low.
If the system is to be shut down for a long period during very
cold weather, it is advisable to completely drain the system.
However, too-frequent draining should be avoided,
especially in hard-water areas, as this could lead to scaling
of the boiler waterways.
CLEANING & GENERAL MAINTENANCE
To clean the casings, isolate the electrical supply and apply
hot soapy water with a damp cloth. Then dry with a second,
soft cloth. Ensure that the natural ventilation around the
boiler is not obstructed. If fitted in a compartment, ensure all
ventilation grilles are clear.
See page 17 for comprehensive fault-finding.
11
FIG. 16

SIMPLE FAULT-FINDING
Should the boiler fail to start for any reason, please make the
following checks before calling a service engineer:
(1) Is the green light illuminated?
No.
Check for a blown fuse or thrown power-breaker.
Yes
(2) Is the 1st red light illuminated?
No
Check to see if all external controls, such as a room
thermostat or programmer, are operational and calling for
heat and proceed to (3).
Yes
If the light is permanently illuminated, switch off all power to
the appliance for at least 30 seconds. This should reset the
boiler and return it to normal operation. If the problem
persists, then a fault has occurred. Please contact a service
engineer for assistance.
If the light is flashing, this indicates that a fault has occurred
with the heating elements. As it contains 2 elements, in this
case the 4kW model will continue to operate safely at a
reduced output. As the 2kW model only incorporates 1
element, the boiler will not operate.
In either case, a fault has occurred. Please contact a service
engineer for assistance.
(3) Is the 2nd red light illuminated?
Yes
This indicates that the system pressure has dropped to
below 1 bar. Check the system pressure and, if necessary,
re-pressurise to above 1 bar.
No
If all system controls (room thermostat/programmer) have
been checked, please contact a service engineer for
assistance.
IMPORTANT NOTE: Electrical safety checks should only
be carried out by a competent person.
Refer to page 16 for after-sales service information.
Acomprehensive fault-finding guide for the service engineer
can be found on page 17.
12
TECHNICAL SPECIFICATION
ELECTRICAL INPUT
SUPPLY CURRENT (amp)
RCD RATING (amp)
WEIGHT (kg)
WATER CONTENT (litres)
WIDTH
DEPTH
HEIGHT
MAINS SUPPLY
MAXIMUM OPERATING PRESSURE
TEST PRESSURE
CONTROL THERMOSTAT - Adjustable between 30°C and 75°C
PRESSURE SWITCH - Set at 1 bar
SAFETY VALVE - Set at 3 bar
EXPANSION VESSEL - 2 litre capacity
PUMP - Grundfos UP15-14B
LIMIT THERMOSTAT (FACTORY FITTED) - Set at 100°C (for wet radiator systems)
LIMIT THERMOSTAT (ALTERNATE) - Set at 60°C (for underfloor heating systems)
PRESSURE GAUGE - 0 to 4 bar
CASING FINISH - Stove enamelled white or bronze
THERMAL INSULATION - Mineral fibre
2kW
8.5A
13A
16
2.0
360
156
580
230V 50Hz
3 bar
43.5 psi
4.5 bar
65 psi
4kW
17.5A
32A
16
2.0
360
156
580
230V 50Hz
3 bar
43.5 psi
4.5 bar
65 psi

INSTALLATION NOTES
REGULATIONS & SAFETY
This boiler must only be installed by a competent person.
The installation must comply with the following regulations
and standards:
The Building Regulations Part L
I.E.E. Wiring Regulations
Local Water Undertaking bylaws.
BS 4814 - Specification for Expansion Vessels for
Sealed Hot Water Heating Systems
BS 6798 - Measurement of Emitted Noise
BS 5449 - Forced Circulation Hot Water Central
Heating Systems
BS 7074 Part 1 - Expansion Vessel Selection,
Code of Practice for Sealed Water Systems
BS 7074 Part 2 - Expansion Vessel Selection,
Code of Practise for Low and Medium
Temperature Hot Water Systems
BS 7593 - Treatment of Water in Domestic Hot
Water Central Heating Systems
BS 7671 - Electrical Wiring Regulations
BS EN 1264 Part 4 - Installation of Floor Heating,
Systems and Components.
The installer should be aware of his/her responsibilities under
the Health and Safety at Work Act and provide, where
necessary, appropriate protection for the person(s) carrying
out the installation. In the interests of safety, a competent
engineer should install the boiler, and all wiring must be
carried out in accordance with current I.E.E. wiring
regulations.
IMPORTANT: This boiler is only to be fitted on fully-
pumped systems.
It is recommended that a scale-inhibitor is added to prolong
the life of the system. Follow manufacturer's instructions for
best practise on installation.
The appliance must not be operated until the system is full of
water and properly vented and pressurised.
Always switch OFF the electrical supply before removing the
front door.
Cardboard packaging is recyclable.
IMPORTANT: To avoid danger of suffocation, please
keep all packaging away from children.
13
Manufacturer's Declaration of Conformity
European Directives Covered by this Declaration:
EN 60335-1: 1994 / A16:2001
EN 60335-2-35:1998 / A1:2000
EN 55014-1:2000
EN 55014-2:1997
EN 61000-3-2:2000
EN 61000-3-3:1995
The Basis on Which Conformity is Being Declared
The products identified herein comply with the requirements of the
Low Voltage Directive (73/23/EEC) and the EMC Directive (89/336/EEC).
Samples of the product have been tested by the manufacturer
and a third-party certification body (The British Standards Institute).
The product has been awarded the British Standards Kitemark (KM 59690).

14
FIG. 17 - BOILER SCHEMATIC

BOILER COMPONENTS (Fig. 17)
The Aztec Gold electric boiler consists of several
components, all integral to the running of the appliance.
PCB CONTROLLER
The Printed Circuit Board controls the operation of the boiler,
bringing the element on and off according to the heating
demand.
Extreme care should be taken when handling the PCB, as
damage to even one component will necessitate the
replacement of the entire unit.
Always ensure the electrical supply to the boiler is switched
off before commencing work on the PCB.
AUTOMATIC AIR VENT
The air vent automatically expels any air generated by the
system.
PUMP (Fig. 18)
The pump is responsible for moving the heated water
throughout the system. The pressure loss throughout the
system is negligible, so all the pressure head developed by
the pump can be used for the system.
EXPANSION VESSEL
The expansion vessel has a capacity of 2 litres and is pre-
charged to 1 bar. This is suitable for a system with a static
head of up to 10 metres.
Note: The air charge should not exceed a pressure of 1.5
bar (22 psi).
The capacity of the expansion vessel is suitable for systems
with a water content of 28 litres (including the boiler). Should
the system volume exceed this capacity, an extra expansion
vessel will be necessary.
An additional expansion vessel will also be necessary should
the system pressure exceed 2.5 bar once the boiler reaches
its highest temperature.
PRESSURE GAUGE
The pressure gauge provides a visual indication of the
system water pressure. Upon installation, the red pointer
should be set to the cold-fill pressure, allowing any drop or
rise in pressure to be easily observed.
PRESSURE RELIEF VALVE
The pressure relief valve will discharge water from the
system should the water pressure exceed 3 bar. Ensure that
the discharge is routed to the outside of the building, does
not discharge above a window, door, or other public access
area, and is easily visible so any discharge can be seen.
PRESSURE SAFETY SWITCH
The pressure switch is set at 1 bar and will automatically
switch off the boiler should the system pressure drop below
this. Pressure loss below 1 bar is indicated by the
illumination of the 2nd red light on the front of the boiler.
HEAT EXCHANGER
The heat exchanger contains the element, which heats the
water as it passes through, and has a water content of 1 litre.
15
FIG. 18 - PERFORMANCE GRAPH

A qualified field service engineer is available to attend
a breakdown occurring during the guarantee period of
the appliance.
The boiler must be made available for service during
normal working hours, Monday to Friday. No weekend
or bank holiday work is accepted.
Step 1: The person(s) who installs this appliance
should thoroughly check his/her work prior to
requesting a service visit from a Trianco
engineer.
Step 2: Contact Trianco. You will be provided with the
name and telephone number of your nearest
service engineer.
Please quote the appliance serial number in any
correspondence with the Service Department. Failure
to provide this will result in a delay in the attendance of
an engineer.
The serial number is located on the lower right-hand
side of the boiler casing.
IMPORTANT NOTES:
An on-site charge will be made where:
a) The service engineer finds no fault with the
appliance.
b) The cause of the breakdown is due to other parts of
the heating system, or equipment not provided by
Trianco.
c) The appliance falls outside the guarantee period.
d) The appliance has not been correctly installed as
recommended within these instructions.
Unauthorised invoices by third-party service
engineers not agreed by Trianco will not be
accepted.
16
SERVICE CENTRE AND TECHNICAL SUPPORT
Tel: [phone] Fax: [phone]
Hours of Business Monday to Thursday: 8:30am - 4:45pm
Friday: 8:30am - 2:30pm
AFTER-SALES SERVICE INFORMATION
A step-by-step guide to reporting a fault with the appliance

FAULT-FINDING
FAULT: 1st Red Light Permanently Illuminated
1) High Limit Thermostat Has Operated
The high limit thermostat is fitted to the front-top of the heat
exchanger and is secured in position by 2 retaining clips. The
thermostat will shut the boiler down if the temperature
reaches 100°C (60°C if the underfloor heating limit stat is
utilised).
To reset, press the button in the centre of the stat. The stat
may have tripped due to one of the following: faulty
circulation pump. isolation valves closed on system, air
trapped in system, no water in system, faulty PCB settings,
faulty high limit thermostat.
Check all electrical connections on the thermostat and PCB.
Using a multi-meter, check for continuity across the
thermostat terminals. If found to be faulty, replace.
2) Thermistor Failure
The thermistor cable is fitted to the front-top of the boiler heat
exchanger, secured in place by use of a retaining clip. The
other end of the cable terminates with a white two-pin
connector onto the PCB.
Check the connections on the PCB for breakages, and make
sure device is correctly fitted. Inspect thermistor cable for
any broken wires. Replace if necessary.
3) Mains Inlet Wiring
The mains supply to the terminal block at the top-left of the
boiler may be incorrectly wired. Check against wiring
diagrams on pages 6/7. Rectify any incorrect wiring.
4) PCB Failure
The PCB may have been damaged during transit or
installation. Inspect the LED connections and temperature
control adjuster for damage. Check all connections to the
PCB are secure and in good condition. If found to be faulty,
replace.
5) Voltage Drop
If the area is subject to voltage fluctuations, the supply to the
boiler may have dropped to below 207v. Resetting the boiler
will restore normal operation. If the problem persists, contact
the electricity supplier for rectification.
FAULT: Power is Present, but No Lights
Illuminated
The fuse on the PCB may have blown. Replace as
necessary. The fuse is located above the PCB transformer
and is rated at 630mA. The fuse may have blown if the 'call'
terminal has been used to supply power to the ancillary
controls.
FAULT: 1st Red Light Flashing
1) Poor Electrical Connections
The electrical connections between the element and the
PCB may be faulty. Check for loose or broken cables and for
damaged terminals on both the heat exchanger and PCB.
Replace cables, PCB or heat exchanger as necessary.
2) Element Failure
To check the elements for failure, disconnect the element
cables and check for continuity across the terminals of each
element. If continuity is present, the element is in good
working condition.
A continuity check should also be made between any of the
element terminals and the heat exchanger body. If continuity
is present in this case, the element is faulty.
If either fault is found, the heat exchanger should be
replaced.
3) High PCB Running Temperature
The PCB controller has an in-built temperature control
sensor which protects the PCB from overheating by shutting
down operation until the temperature has returned to
acceptable levels. The boiler will then resume operation and
work normally. However, the red light will continue to flash to
indicate that a problem occurred.
To reset, switch off the the mains power supply to the boiler
for at least 30 seconds, before switching back on.
Check ventilation around the appliance and make sure the
good flow of air into the casing is not impeded by towels,
linen, etc.
FAULT: 2 nd Red Light Permanently Illuminated
1) Low Pressure
The system pressure may have fallen to below 1 bar. Check
reading on pressure gauge and re-pressurise the system as
necessary. Check wiring to pressure safety switch and
indicator light. If no pressure change is indicated on pressure
gauge, replace gauge.
If problem persists, check all joints and connections on
system for leaks.
FAULT: Green Light Illuminated, But Boiler Not
Functioning
Check all external controls are wired correctly and are calling
for heat. If no controls fitted, check wiring against diagrams
on pages 6/7. Check link wire 'A' is fitted in correct position.
17

SERVICING
To ensure the continued safe and reliable operation of the
boiler, it is recommended that it is serviced at least once a
year
Please note that the person(s) who carries out any remedial
work, e.g. electrical fault-finding, should have suitable
engineering qualifications.
PROCEDURE
1) Isolate the mains supply to the boiler.
2) Check that all electrical connections to and from the PCB
and heat exchanger are secure and clean.
3) Check electrical insulation on wiring.
4) Ensure all air grilles are clean and free from any
obstruction.
5) Check water pressure and re-pressurise as necessary.
PARTS REPLACEMENT
IMPORTANT: Isolate mains electricity supply to the boiler
before carrying out any maintenance work. All electrical
connections should be checked as loose connections can
cause problems.
FRONT CASING REMOVAL
Remove the 2 x screws from the top of the boiler and the
single screw on the underside. The door can then be
removed safely.
PCB REPLACEMENT (Fig. 19)
1) Ensure the electrical supply to the boiler is isolated.
2) Remove the front casing as described above.
3) Unscrew the 2 x fixing screws holding the PCB mounting
bracket in position, allowing the unit to be pulled forward.
4) Holding the PCB assembly firmly in one hand,
disconnect the thermistor plug, pump and call plug on the
left hand side and the high limit thermostat plug on the
right hand side.
5) Taking care not to damage the PCB, pull the assembly
out a little further and disconnect the remaining mains
and element cables from the PCB.
6) Remove the 4 x fixing screws securing the PCB onto the
mounting bracket and replace with the new PCB unit.
7) Re-fit in reverse order, taking care to replace all cables
back into their original positions. Refer to wiring
diagrams on pages 6/7 for assistance.
18
FIG. 19 - PCB CONTROLLER

PARTS REPLACEMENT (cont.)
HIGH-LIMIT THERMOSTAT REPLACEMENT (Fig.
20)
1) Ensure the electrical supply to the boiler is isolated.
2) Remove the 2 cable ends from the thermostat.
3) Loosen the retaining clips slightly, and slide the
thermostat out.
4) Replace with new thermostat and re-fit in reverse order,
using a suitable heat-transfer paste.
Note: High-limit thermostat must be fixed tightly to
ensure accurate sensing of temperatures.
THERMISTOR REPLACEMENT (Fig. 21)
1) Ensure the electrical supply to the boiler is isolated.
2) Loosen the retaining clip slightly and slide cable end out
from underneath.
3) Disconnect remaining end from PCB.
4) Replace thermistor and re-fit in reverse order, using a
suitable heat-transfer paste.
Note: Thermistor must be fixed tightly in position to
ensure accurate sensing of temperatures.
HEAT EXCHANGER REPLACEMENT (Fig. 22)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Disconnect element cables, earth cable and thermistor
cable. Remove pump cable from terminal block.
5) Disconnect compression fittings at bottom of heat
exchanger on left-hand side and flow pipe at right-hand
side. Remove the fixing screw from the underside of the
heat exchanger and unclip the retaining clips from the
flow pipework.
6) Taking care not to damage any components, remove the
whole hydraulic assembly from the manifold.
7) In a secure position, disconnect the compression fittings
holding the heat exchanger in place. Remove the limit
stat, insulation and thermistor. Replace with the new unit,
refitting parts in reverse order.
8) Re-fill the system as described on pages 7/8, and open
isolating valves.
19
FIG. 20 - HIGH LIMIT THERMOSTAT
FIG. 21 - THERMISTOR
FIG. 22 - HEAT EXCHANGER

PARTS REPLACEMENT (cont.)
PRESSURE SAFETY SWITCH REPLACEMENT
(Fig. 23)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Disconnect the three wires from the top of the pressure
safety switch.
5) Unscrew pressure safety switch and replace with a new
unit, re-fitting in reverse order.
6) Re-fill the system as described on pages 7/8, and open
isolating valves.
Notes: Do not over-tighten connections to manifold as this
could lead to thread damage.
Ensure a suitable thread sealant is used when screwing
switch into position.
EXPANSION VESSEL REPLACEMENT (Fig. 24)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Unscrew the expansion vessel and replace with a new
unit, re-fitting in reverse order. Ensure a suitable thread
sealant is used on all joints.
5) Re-fill the system as described on pages 7/8, and open
isolating valves.
PUMP HEAD REPLACEMENT (Fig. 25)
1) Ensure the electrical supply to the boiler is isolated.
2) Close the isolating valves to the boiler (if fitted).
3) Drain system via drain/fill point on front of manifold.
4) Disconnect the pump power supply cables from the
terminal block and unscrew pump head.
5) Clean any deposits from the inside of the body and
replace the 'o' ring seal, if necessary.
6) Replace the pump head with a new unit, re-fitting in
reverse order.
7) Re-fill the system as described on pages 7/8, and open
isolating valves.
20
FIG. 23 - PRESSURE SWITCH
FIG. 24 - EXPANSION VESSEL
FIG. 25 - PUMP HEAD