Trianco CLASSIC 2KW Training manual

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CLASSIC 2, 6, 9, 11 & 12kW BOILER
INSTALLATION, OPERATION AND
SERVICING INSTRUCTIONS
Please read these instructions carefully before installing
and operating this appliance

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CONTENTS PAGE
HEALTH AND SAFETY 3
PRE INSTALLATION NOTES 4
AFTER SALES INFORMATION 5
INTRODUCTION 6
USERS INSTRUCTIONS 7
SIMPLE FAULT FINDING 8
INSTALLATION INSTRUCTIONS 9
Regulations 9
Health and safety 9
Siting the boiler 9
Fixing to the wall 9
Dimensional details 9
Ventilation 10
Water systems 11 - 12
Multiple boiler installation 12
Wiring instructions 14 - 19
SERVICE INSTRUCTIONS 20
Parts replacement 20 - 21
Fault finding 22 - 26
Spares list 27 - 28
IMPORTANT:
General Information:
To keep your boiler running efficiently DO NOT OBSTRUCT OR COVER any ventilation air inlet on the appliance
or the compartment where it is installed.
To keep the casing clean, switch ‘OFF’ the boiler at the electrical supply, and simply wipe with a damp cloth.
DO NOT use abrasive cleaning fluids as this may damage the stove enamel paintwork.
Important
The electrical supply requirements:-
The 2kW boilers and 6kW boilers meet the requirements of EN 61000-3.3.
The 9kW and 11kW boiler must be installed in premises having a service of ≥100A per phase.
The 12kW boiler must be installed in premises having a system impedance of not more than 0.1939 + 0.1939Ω.
PAGE
3
4
5
6
7
8
9
9
9
9
9
9
10
11 - 12
12
14 –19
20
20 –21
22 –26
27 - 28

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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 Users/Engineers responsibility 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.
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, Sealants and Paints are used in the product and present no known hazards when used in the manner for
which they are intended.
Notes:
a) Electrical safety checks should be carried out by a competent.
b) It is a requirement of the guarantee and any extended warranty that an annual service is carried out by a
competent person.
Installation Engineers Signature
Company Name (if applicable)
Company Address
Company Tel. No.

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IMPORTANT PRE-INSTALLATION NOTES
Before installation, it is imperative that the following guidelines are heeded to ensure the trouble-free and
efficient operation of the boiler:
Ventilation and Siting
When siting the boiler in a confined space it is essential that adequate ventilation be provided. This will ensure
that air is allowed to circulate freely around the appliance keeping down the ambient temperatures. Refer to
Ventilation Requirements (page 10) for further details.
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, etc).
When siting the boiler, take into account the potential requirement for future servicing. Enough space should
be provided at the front of the boiler to enable an engineer to adequately service and/or replace items such as
the PCB or heat exchanger. Space should also be available for the removal of the front casing panel. Please
refer to siting information (page 9) for clearance dimensions.
Power Supply and Wiring
The power supply to the must meet the minimum requirements of the unit being installed, with special
attention paid to the supply current, cable size, and RCD recommendation. The supply voltage to the appliance
must never drop below 207 volts.
When fitting external controls, such as a room thermostat or programmer, particular consideration should be
given to the wiring of these secondary items into the appliance. Please refer to the wiring instructions (pages
14 to 22) for full details. Any breakdown attended to by T R Engineering Ltd which is found to be caused by an
incorrectly wired appliance will be chargeable.
It is important that the pump is wired back to the boiler as shown in the wiring diagram.
System
Isolation valves must be fitted on both the flow and return pipe work of each boiler to be installed. These are
useful as –as from time to time –the boiler may require draining of water, and the lengthy drawing-off
process can be avoided by the astute placement of these valves. Please refer to page 11 for further details.
Ensure that any isolation valves are open before first use, and that the system is full of water.
The boiler can be fitted only in an upright position, with the flow connection to the top of the boiler.

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A qualified field service engineer is available to attend a
breakdown occurring during the boiler’s guarantee
period.
The boiler must be made available for attendance during
normal working hours, Monday to Friday.
How to report a fault
Step 1
Contact your installation or service engineer, who
should assess the unit and works carried out on the
appliance prior to requesting the attendance of an
engineer from T R Engineering Ltd.
Step 2
Please note that upon attendance by a T R
Engineering engineer, a charge will be made
where:
-The engineer finds no fault with the boiler.
-The cause of the breakdown is due to parts of the
system not manufactured or supplied by T R
Engineering.
-The cause of the breakdown is due to incorrectly fitted
spare parts, or third-party spares not designed for use
with the boiler.
-The boiler has not been installed in accordance with
these instructions.
-The boiler has not been commissioned by a qualified
engineer.
-The boiler has not been serviced annually since
installation.
-The breakdown occurs outside the guarantee period.
-The appliance has not been maintained correctly.
-The breakdown occurs due to use of the boiler not
sanctioned by these instructions.
-The breakdown occurs as a result of work on the
appliance by an unauthorised third-party.
Important:
Invoices for attendance and repair work by any third
party will not be accepted unless authorised in advance
by T R Engineering Ltd.
Technical Assistance
A team of trained technical advisors are available to
discuss any problem with the appliance. In many cases,
the problem may be solved over the telephone,
eliminating the need for an engineer’s visit.
Before making contact, please have the following
information ready:
-The appliance serial number or your unique customer
identification number (issued upon registration of the
appliance with T R Engineering Ltd).
-A description of the fault and any unusual behaviour by
the boiler before the failure occurred.
-The installation and commissioning dates, and the
details of any annual services.
After Sales Service Information
Appliance Serial No: t
Cust. ID No: t
Installation Date: / / t
Service Centre and Technical Support
Tel: [phone] Fax: [phone]
Hours of Business
Monday –Thursday 8:30am –17:30pm
Friday: 8:30am –14:30pm

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1. INTRODUCTION
The Aztec Electric Boiler is a wall mounted electric
central heating boiler designed with smaller properties
in mind. Fitted vertically only and requiring access to the
front and the right hand side of the boiler for servicing.
Once the boiler is switched on it is fully controlled by an
automatic management system which monitors the
safety and running functions of the boiler. Designed to
work on a fully pumped wet system only. The boiler
produces hot water by passing water over electric
heating elements housed in an insulated stainless steel
heat exchanger.
There are five boilers in the range with outputs ranging
from 2kW (6825 Btu/hr) to 12kW (41,000 Btu/hr).
IMPORTANT SAFETY NOTES
Read these instructions before installing your boiler.
The heating system must comply with the latest editions
of British Standards 5449 and The Building Regulations,
and Electrical Wiring Regulations BS 7671.
1. Always switch OFF the electrical supply before
removing the cover.
2. If any part of the boiler is modified, then the
guarantee/warranty will be invalidated.
We recommend that you keep these instructions in a
place near your appliance for easy reference.
The Trianco Aztec Wall Mounted Boiler has been designed to conform to European
Directive/Standards.
EN60335-1:1994/A16:2001, EN60335-2-35:1998/A1:2000, EN55014-1:2000, EN55014-
2:1997, EN61000-3-2:2000 and EN61000-3-3:1995.
THE PERSON(S) WHO INSTALLS THIS APPLIANCE, SERVICES OR CARRIES OUT ANY
REMEDIAL WORK, I.E. ELECTRICAL FAULT FINDING, MUST HAVE SUITABLE ENGINEERING
QUALIFICATIONS.
WARNING: DO NOT SWITCH ON THIS APPLIANCE IF THERE IS ANY POSSIBILTY THAT THE
WATER HEAT EXCHANGER IS FROZEN.
THE INSTALLATION OF THIS APPLIANCE MUST MEET THE REQUIREMENTS OF THE
CURRENT ISSUE FOR ELECTRICAL INSTALLATIONS IEE WIRING
REGULATIONS

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2. USERS INSTRUCTIONS
The Trianco Aztec 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 the thermostat
and any external system controls such as a room
thermostat and time switch.
IMPORTANT
DO NOT COVER OR BOX IN YOUR BOILER, ALLOW AIR
TO CIRCULATE FREELY AROUND THE APPLIANCE
WARNING: DO NOT ATTEMPT TO SWITCH ON THE
BOILER IF THERE IS ANY POSSIBILTY THAT THE WATER
HEAT EXCHANGER IS FROZEN
Before firing the boiler, ensure the system is full of
water and any valves fitted to system are open.
Check that the time switch/programmer (if fitted) is
ON and the room thermostat is calling for heat.
Switch on the electrical supply to the boiler and
after a few seconds the boiler’s green and amber
light should illuminate.
Set the boiler thermostat to the required
temperature using the control buttons.
Set the time switch/programmer (if fitted) to the
times and programmers required.
The boiler will now operate automatically, cutting
in and out according to heat demand.
TO TURN OFF THE BOILER
Switch off the boiler at the time
switch/programmer (if fitted).
If the boiler is to be switched off for any length of
time it is recommended that the mains supply to
the boiler is switched OFF.
BOILER CONTROL THERMOSTAT
The boiler control thermostat enables you to select the
temperature of the water leaving the boiler. It is
calibrated between 35°C and 75°C.
Using a small screwdriver set the temperature by
turning the knob to the required setting or when the
case is fitted use the buttons to switch between low and
high (35°C and 75°C in 5 degree increments).
BOILER INDICATOR LIGHT
There are three LED indicator lights on the boiler fascia
panel these are:
LED 1 –GREEN –Power on to the boiler
LED 2 –AMBER –Illuminated- in run mode
Flashing –Temperature satisfied
LED 3 –RED –Boiler fault
LED 4-12 –RED –Temperature lights
If the red LED light flashes, this means a fault has
occurred. This would result in the boiler continuing to
operate at a reduced output.
If the red LED is permanently on, this indicates a fault
has occurred. (See simple fault finding chart on page 8).
ROOM THERMOSTAT
The room thermostat should not be positioned near a
source of heat such as a radiator or exposed to the sun
as this will cause the central heating to switch off before
the room is up to temperature. Follow the
manufacturer’s instructions for best siting position for
the thermostat.
FROST PROTECTION
If the boiler and central heating is shut down for many
hours during very cold weather, the water may be in
danger of freezing. The boiler incorporates a frost
thermostat.
If the system is shut down for a long period during very
cold weather, it is advisable to completely drain the
system. However, frequent draining should be avoided,
especially in hard water areas, as this could lead to
scaling of the boiler waterways.
WARNING: DO NOT SWITCH ON THIS APPLIANCE IF
THERE IS ANY POSSIBILITY THAT THE WATER HEAT
EXCHANGER IS FROZEN.
BOILER PUMP OVERRUN
The pump will overrun for a short period of time after
boiler turns off.
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 suggested that the time switch/programmer is set to
bring on the heating about an hour after boiler
shutdown. The timer can therefore be switched off
earlier as an economy measure.
Cleaning Casings
Use hot soapy water applied with a damp dry cloth for
the enamel, then dry with a soft dry cloth.
Simple Maintenance
Ensure that the natural ventilation around the boiler is
not obstructed. If fitted in a compartment ensure all
ventilation grilles are clear.

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SIMPLE FAULT FINDING
If the boiler fails to start for no apparent reason make
the following checks before calling your service
engineer.
1. Is the green LED light illuminated?
NO
2. If the red LED is permanently illuminated
contact your service engineer.
3. Flashing red LED indicates an open circuit. The
boiler can still be operated. Service engineer
should be contacted.
3. TECHNICAL SPECIFICATION
MODEL
AZTEC
2KW
AZTEC
6KW
AZTEC
9KW
AZTEC
11KW
AZTEC
12KW
ELECTRICAL INPUT
2kW
6kW
9.15kW
11kW
12kW
SUPPLY CURRENT (amp)
8.5A
25A
39A
45A
51A
RCD RATING (amp)
13A
32A
40A
50A
63A
MINIMUM CABLE SIZE (mm)
1
4
6
10
16
WEIGHT (kg)
7.0
8.1
10.6
10.8
10.8
WATER CONTENT (litres
1.0
2.1
3.2
3.2
3.2
WIDTH (mm)
164
164
164
164
164
DEPTH
130
130
130
130
130
HEIGHT
550
823
1073
1073
1073
MAINS SUPPLY
230v 50Hz
MAX OPERATING PRESSURE
3bar
43.5 psi
TEST PRESSURE
6 bar
87 psi
BOILER FLOW TEMPERATURE –Adjustable between 35°C and 75°C, located on the front casing
LIMIT THERMOSTAT –Factory set at 100°C
CASING FINISH –Stove enamelled white
4. Checks to see if all external controls i.e. programmer
or room thermostat are calling for heat.
Resetting the Boiler
If a fault has occurred and the red LED is illuminated but
the pump continues to run, then switching the power off
for 30 seconds and then on again should reset the light.
This may be caused by the ambient temperature around
the boiler being too high. Check to ensure that any boiler
ventilation is not obstructed. If the fault reoccurs contact
your engineer.
IMPORTANT: Electrical safety checks should be carried
out by a qualified electrical engineer.

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2kW
6kW
9 –12kW
A
566
839
1089
B
586
859
1109
C
550
823
1073
D
107
107
107
E
164
164
164
4. Installation
Regulations
Installation of the boiler must comply with the following
British Standards and Regulations:
BS 5449 –Forced Circulation Hot Water Central Heating
Systems.
BS 7074 –Part 1 –Code of Practice for Sealed Water
Systems.
The Building Regulations
Part ‘L’ (Northern Ireland)
Current I.E.E. Regulations
Local water undertaking By-Laws
Health & Safety at Work Act
The installer should be aware of his responsibilities under
the Act and provide where necessary, appropriate
protection for persons 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 IEE wiring regulations.
ALL ELECTRICAL WORK MUST BE CARRIED OUT BY A
QUALIFIED ELECTRICAL ENGINEER TO CURRENT IEE WIRING
REGULATIONS.
SITING THE BOILER
IMPORTANT: NOT TO BE INSTALLED IN A SHOWER
COMPARTMENT OR BATHROOM
The boiler is designed to be fitted in an upright position
only. Ensure adequate clearance is allowed for making water
connections as the boiler can be fully serviced from the
front. The boiler must also be fitted in a dry well ventilated
position, which is not subject to adverse temperature
conditions. (See Ventilation Requirements)
Care should be taken when siting the appliance to make sure
adequate access is available for future servicing of the
appliance. Please note that the PCB and heat exchanger
assembly may require removal during such times.
When installed in a compartment with a hot water cylinder
(see. Fig. 1), we recommend that the boiler is fitted in
position 1; if fitted in position 2, provision should be made at
the front of the boiler to enable the removal of the front
casing. In both cases, where any additional equipment like a
hot water cylinder or system controls are to be fitted after
the boiler has been installed, attention should be given to
ensure that they do not restrict access to the boiler for
servicing.
IMPORTANT
UNPACKING THE BOILER
Carefully open the boiler carton, remove boiler and place in
a safe place until required.
NOTE –ALWAYS STORE THE BOILER IN A DRY PLACE
PRIOR TO FITTING. DO NOT ALLOW THE BOILER TO BE
STORED WITH THE CASING REMOVED.
FIXING BOILER TO WALL
IMPORTANT:
DO NOT CUT FLOW AND RETURN PIPES
1. The boiler should be fitted to a suitable wall in an
upright position. Flow tapping must be at top of boiler.
2. Using fixing dimensions supplied work out position of
boiler, mark four mounting holes and drill 6mm
diameter to a depth of 38mm.
3. Fit plastic wall plugs into holes and fit bottom two
mounting screws.
4. Hang on bottom two screws and push the boiler back
towards the wall and secure in position with top two
fixing screws. The flow tapping must be at top of the
boiler. (continued, page 10)
FLOW ᴓ22
A
B
C
D
E
RETURN ᴓ22
Fig. 3
MINIMUM CLEARANCES:
FRONT –150mm
FROM OTHER FIXED EQUIPMENT
TOP –100mm
BOTTOM –100mm
L/H SIDE –50mm
R/H SIDE –100mm
NOTE: APPROXIMATELY 750MM WILL BE
REQUIRED AT THE FRONT OF THE APPLIANCE
TO ENSURE ADEQUATE ACCESS BY AN
ENGINEER DURING ROUTINE SERVICING.

10
5. Removing four casing screws and washers will allow
casing to be removed.
6. Slide top casing cap upwards this will allow front casing
to slide forward.
7. With the front casing removed fit three strain relief
bushes into base of back panel.
8. Fit pipe sealing grommet into top casing panel and cut
off end to allow pipe to slide through (see diagram)
IMPORTANT: TOP CASING PANEL WITH GROMMET MUST
BE RE-FITTED BACK IN POSITION BEFORE MAKING TOP
PIPE CONECTION. ALTERATION OR FAILURE TO COMPLY
WILL INVALIDATE THE WARRANTY.
9. When re-fitting casings slide front casing back into
position ensure small temperature adjuster on PCB
passes through the hole on the control panel. Slide the
top-casing panel down into position and secure panels
into position using the four screws.
VENTILATION REQUIREMENTS
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 100cm2will be required to the
compartment, in both high and low level positions.
100cm2
100cm2
AZTEC
ELECTRIC
BOILER

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MODEL
MIN FLOW RATE / Min
AZTEC 2 kW
4 LTRS
AZTEC 6 kW
8 LTRS
AZTEC 9 kW
10 LTRS
AZTEC 11 kW
11 LTRS
AZTEC 12 kW
12 LTRS
WATER SYSTEM
IMPORTANT: USE ONLY COMPRESSION FITTINGS WHEN
CONNECTING THE BOILER TO THE CENTRAL HEATING
SYSTEM
The installation must comply with the requirements of the
following codes of practice.
BS 5449 Part 1 Forced Circulation Hot Water Systems.
BS 7074 Part 1 Code of Practice for Sealed System Water
Systems.
BS 7593 Treatment of water in domestic hot water central
heating systems.
The water system must be thoroughly flushed out with
cold water without the pump in position. Refit the pump
and fill the system. Vent all air from the system. Clear any
air locks and examine the system for water leaks.
IMPORTANT: ENSURE ALL SERVICE VALVES ARE IN OPEN
POSITION.
Ensure boiler is fitted with flow pipe at top and return
pipe at bottom.
The boiler is supplied with 22mm tail pipes top and
bottom for connection to system.
The boiler must be installed using 22mm compression
fittings both top and bottom.
The AZTEC ranges of boilers are low water content boilers
so require a good flow rate at all times (see chart).
AZTEC boilers are approved for use on fully pumped open
vented systems and sealed systems. When fitting on a
sealed system a 3 bar safety valve must be fitted to
system, where thermostatic radiator valves are fitted it
will be necessary to fit a bypass to obtain min flow rates.
IMPORTANT: IF MIN FLOW RATES ARE NOT OBTAINED
THE BOILER MAY GO TO LOCK OUT ON HIGH LIMIT
THERMOSTAT.
Where more than 1 boiler is fitted refer to multiple boiler
instructions.
System must be flushed out before adding inhibitor to BS
7593: 1992 treatment of water in central heating boiler.
IMPORTANT: THIS BOILER IS TO BE FITTED ON FULLY
PUMPED SYSTEMS ONLY.
SEALED WATER SYSTEM
REQUIREMENTS
The installation must comply with the appropriate
requirements of the current issue of BS 4814, BS 5449, BS
6798 and BS 7074 Part 1 and 2.
THE INSTALLATION ENGINEER MUST BE REGISTERED AS
A COMPETENT UDHWSS INSTALLER.
Safety Valve
A safety valve set at 3 bar must be fitted with the drain routed
to the outside of the building. The drain must not discharge
Expansion Vessel Capacity
A diaphragm type expansion vessel, conforming to the current
issue of BS 4814. The expansion vessel must be connected to
the systems at a point close to the inlet side of the circulating
pump. The expansion vessel volume depends on the total
water system volume and the initial system design pressure.
For any system an accurate calculation of vessel size is given in
the current issue of BS 5449 and BS 7074 Part 1.
The water content of the boiler is given in Technical
Specification. Note a higher initial design pressure requires a
larger volume expansion vessel.
The charge pressure must not be less than the static head of
the system that is the highest point of the system above the
expansion vessel.
Capacity of expansion vessel
Where design information is not complete the following chart
(page 12) can be used for selecting the size of the vessel, it
should be noted that the size given in the table take account of
fault conditions.
System Temperature
The normal running temperature of the system is 75°C, if a
fault was to occur then the safety device would allow the
system temperature to rise to 100°C. It is recommended that
this figure be used in the calculations of vessel size.
Connection of the expansion vessel
The expansion vessel should be connected in the neutral part of
the system this being the return pipe work close to the boiler,
refer to sealed system pipe work layout drawing. (Fig. 12)
Pressure Gauge
A pressure gauge must be permanently fitted in the system
covering a range from 0 to 4 bar. Position where it can be
seen when filling system.
Inhibitor
If using an existing system, take care to drain down the entire
system including the radiators then thoroughly clean out before
fitting the boiler. Attention is drawn to the current issue of BS
5449 and BS 7593 on the use of inhibitors in central heating
systems.
Drain Tapping
A drain tapping must be provided at lowest point of the
system, which will allow the entire system to be drained.
NOTE: Failure to ensure the correct vessel size could result in
premature failure of the expansion vessel which in turn may
adversely affect other components in the system i.e,
circulating pump and diverter valve.
System Makeup
Water loss from the system should be replaced from a
makeup vessel connected to the system. This vessel should be
higher than the top of the system. Alternatively provision can
be made by pre-pressurisation of the system via a temporary
hose connection and through a double check valve (non-
return) and stop valve. There must be no permanent
connection to the mains water supply even through a non-
return valve.
above an entrance or a window or any public access area, be
clear of any electrical fittings and positioned so that any
discharge can be seen.

12
Safety valve setting (bar gauge)
3 bar
Vessel charge and initial system pressure (bar gauge)
0.5
1.0
1.5
Total water content of system
Vessel Volume
Litre
Litre
Litre
Litre
25
2.3
3.3
5.9
50
4.4
6.7
11.8
75
7.0
10.0
17.7
100
9.4
13.4
23.7
125
11.7
16.7
29.6
150
14.1
20.1
35.5
175
16.4
23.4
41.4
200
18.8
26.8
47.4
MULTIPLE BOILER INSTALLATIONS
Important
Where a greater output is required, more than one
boiler can be used in the same system. However, if
installing a circulating pump with a higher power
demand, the PCB circuit protection fuse may not be
adequate. The pump could be wired using a relay.
See wiring instructions (page 15 Fig. 14) for further
details.
The boilers must be fitted side by side using common
flow returns. For each additional boiler fitted, it is
recommended that the pipe work is increased in size
and the pump set to deliver the combined flow rates.
The circulating pump will be connected to one of the
boilers or via the relay.
We strongly recommend the positioning of
isolation valves on the flow and return pipe work
of each boiler, as there may be a need to isolate
one or more during servicing. (see Fig. 10)
Please contact the Technical Support team for
further information.

13
Auto
Auto

14
WIRING INSTRUCTIONS
ALL ELECTRICAL WORK MUST BE CARRIED OUT IN
ACCORDANCE WITH CURRENT IEE WIRING
REGULATIONS.
BEFORE COMMENCING INSTALLATION CHECK
POWER SUPPLY TO PROPERTY TO ENSURE THAT
THERE IS SUFFICIENT CURRENT AND VOLTAGE
AVAILABLE FOR SIZE OF BOILER BEING FITTED. TAKE
INTO ACCOUNT REQUIREMENTS OF OTHER
ELECTRICAL APPLIANCES. THE BOILER MUST BE
CONNECTED TO THE MAINS SUPPLY BY MEANS OF A
DOUBLE POLE LINKED SWITCH WITH 3MM CONTACT
GAP IN BOTH POLES.
IMPORTANT: After completing electrical installation
work preliminary safety checks should be carried out
as described in BS 7671:2001.
IMPORTANT:
The electrical supply requirements:-
The 2 kW boilers and 6 kW boiler supplies should
meet the requirements of EN 61000-3.3.
The 9kW and 11kW boiler must be installed in
premises having a service supply of ≥100A per phase
and meet the requirements of IEC 60417-5855.
The 12kW boiler must be installed in premises having
a system impedance of not more than 0.1939 +
0.1939Ω.
A double pole RCD with trip level sensitivity of 30ma
Can be used capable of breaking full load current to
BS EN61008: 1994.
NOTE RCD UNIT can be used as the isolating switch if
mounted close enough to the boiler.
Miniature circuit breakers MCB MUST be fitted
between RCD unit and boiler and RCD and any
external controls. Refer to technical specification. For
MCB ratings refer to wiring diagram.
It is important the correct size MCB is used in the
supply from the RCD to the boiler. An additional MCB
rated 6 A will be required to supply the external
controls.
ELECTRICAL CONNECTIONS
WARNING: THIS APPLIANCE MUST BE EARTHED.
The mains connection block is located inside the
boiler on a bracket at top left hand side of the boiler
which can be directly wired to the boiler MCB. Use
the correctly rated cable.
Where the pump is wired directly back to the boiler
both live and neutral connection must be used with
the earth being wired back to the earth post. This is
important as the pump is controlled by a switched
neutral. This also applies to pumps being controlled
by a relay.
IMPORTANT: CORRECT POLARITY MUST BE
OBSERVED WHEN BRINGING THE MAINS SUPPLY
INTO THE BOILER.

15
WIRING INSTRUCTIONS
(CONTINUED)
3 PHASE SUPPLY CONNECTIONS FOR 2 OR
MORE BOILERS
MAINS SUPPLY CABLES
Connect each boiler to each phase.
CONTROLS SIGNAL
Wire as shown in wiring diagram.
PUMP CONNECTIONS
The pump to be connected to one boiler only.
See wiring diagram.
IMPORTANT: ALL ELECTRICAL CONNECTIONS
SHOULD BE CHECKED, LOOSE CONNECTIONS CAN
CAUSE PROBLEMS.
WARNING: THIS APPLIANCE MUST BE EARTHED
1. Any exposed pipe work must be earthed in
accordance with IEE regulations.
2. On completion of installation all electrical; work
must be tested to IEE regulations and NICEIC
inspection and completion certificate must be
issued.
IMPORTANT: When a 3-phase supply, a warning
notice MUST be placed by the boiler to indicate a
voltage in excess of 250V.

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WIRING DIAGRAM FOR HEATING ONLY

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WIRING DIAGRAM FOR S PLAN CONTROL SYSTEM

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WIRING DIAGRAM FOR Y PLAN CONTROL SYSTEM

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ELEMENT 1
ELEMENT 3
ELEMENT 4
This link needs to be left connected on installation.

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5. SERVICING
To ensure reliable operation of your Aztec electric boiler,
it is recommended that you have your boiler serviced
once a year.
The person(s) who services or carries out any remedial
work, i.e. electrical fault finding, must have suitable
engineering qualifications.
Isolate mains supply before carrying out any service
work.
1. Check all electrical connections on PCB and electric
elements to ensure they are secure and clean.
2. Check electrical insulation on wiring.
3. Ensure all air grilles are clean and free from
obstructions.
4. Inspect seals around elements and also the heat
exchanger top and bottom flanges.
PARTS REPLACEMENT
Casing removal
IMPORTANT
Isolate mains electrical supply to the boiler before
carrying out any maintenance work.
1. Isolate electrical supply to boiler.
2. Remove 4 fixing screws securing front casing in
position.
3. Slide top casing upwards this will allow front casing
to slide forward.
FIXING SCREWS
TOP AND BOTTOM
4 FIXING
SCREWS
PCB
CONTROL
UNIT
IMPORTANT: All electrical connections should be
checked. Loose connections can cause problems.
This boiler is fitted with a manual reset high limit
thermostat. Before replacing any part, ensure that the
thermostat does not require re-setting.
PCB Assembly Replacement
1. Ensure electrical supply is isolated to boiler.
2. Remove the 4 fixing screws and washers (2 at top/2
at bottom), lift up the top-plate and carefully slide
off the front casing panel.
3. Disconnect the pump + Call plug, the thermistor
plug and the high limit stat plug.
4. Disconnect all element cables apart from the rear
element. N.B. Take note of wiring arrangement
before disconnecting.
5. Now remove the grey pipe insulation, it is now
possible to disconnect the remaining element.
6. With all elements disconnected, again taking note
of wiring arrangement, carefully disconnect and
remove the element cables from the PCB.
7. Important: Care MUST be taken when handling the
PCB.
8. For ease of access disconnect from the main
terminal block both the red + black cables and also
the power input cables, leaving the earth cable
connected.
9. Free both the pump and call terminal blocks by
removing the terminal block fixing screws.
10. Finally remove the 4 fixing screws holding the PCB
to the bracket.