EHC Fusion Astro Series User manual

rev.no:04
27.09.2019
If you require any further assistance:
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or visit our website www.electric-heatingcompany.co.uk
The Astro Range of Boilers
the ultimate solution for central heating & hot water
INSTALLATION
&
TECHNICAL MANUAL

1. SAFETY
1.1 SYMBOL KEY
1.2 SAFETY PRECAUTIONS
1.3 GENERAL EXPLANATIONS
1.4 INSTRUCTIONS AND BUILDING REGULATIONS
1.5 C.O.S.H.H
1.6 PREPARATION
1.6.1 Load Check
1.6.2 Boiler Location
1.6.3 Central Heating Installation
2. INTRODUCTION
2.1 APPERANCE AND EXTERNAL DIMENSIONS
2.2 COMPONENTS OF THE BOILER
2.3 MAIN FEATURES OF THE BOILER
3. MOUNTING AND INSTALLATION
3.1 OPENING THE BOX
3.2 MOUNTING INSTRUCTIONS
3.3 MINIMUM SPACES FOR INSTALLATION
3.4 WALL MOUNTING
3.5 HEATING AND DHW SYSTEM INSTALLATION CONNECTIONS
3.5.1 BOILER INSTALLATION SCHEMATICS
3.5.2 CIRCULATION PUMP IMFORMATION
3.6 ELECTRICAL CONNECTIONS
3.6.1 Electricity Connection Precautions
3.6.2 Removing the Front Boiler Cover
3.6.3 Electricity Supply Connection
3.6.4 Electrical Connection Diagram 230V (Single Phase)
3.6.5 Electrical Connection Diagram 400V (3-phase)
3.7 MAIN PCB DIP SWITCHES
3.7.1 Switches 1
3.7.2 Switches 2
3.8 ROOM THERMOSTAT CONNECTION
3.9 ELECTRICITY CONNECTION PARAMETERS
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Page 8/9
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CONTENT
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5. USER INSTRUCTIONS
5.1 CONTROL PANEL
5.2 ERROR CODES
5.3 TROUBLE SHOOTING
6. PRODUCT SAFETY
6.1 BUILT-IN RCD DEVICE (SHORT CIRCUIT RELAY)
6.2 HEATING TANK FLOAT LEVEL SENSOR (H6)
6.3 LOW WATER PRESSURE
6.4 OVERHEAT LIMIT THERMOSTAT
6.5 SHORT CIRCUIT THERMOSTAT
6.6 FROST PROTECTION
6.7 DOMESTIC HOT WATER NTC SENSOR
6.8 CENTRAL HEATING NTC SENSOR
6.9 HIGH WATER PRESSURE PROTECTION
6.10 ANTI PUMP LOCKING
6.11 3-WAY VALVE ACTUATOR MOTOR SAFETY
6.12 AUTOMATIC BY-PASS
7. TECHNICAL TABLE
8. MAINTENANCE
9. GUARANTEE CONDITIONS
10. EXPLODED VIEW
10.1 MAIN HEAT EXCHANGER GROUP DETAIL
10.2 HYDROLIC GROUP DETAIL
10.3 RELAY BOARD GROUP DETAIL
10.4 EXPLODED VIEW PARTS LIST
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4. COMMISSIONING
4.1 FILLING WATER TO THE SYSTEM
4.2 STARTING UP

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This appliance is not intended for use by persons (including children) with
reduced physical, sensory or mental capabilities or lack of experience and
knowledge unless they have been given supervision or instruction concerning
the use of the appliance by a person responsible for their safety.
Children should be supervised to ensure that they do not play with the appliance.
1. SAFETY
1.1 SYMBOL KEY
This symbol expresses the risk of serious personal injury or death.
This symbol expresses the risks which can cause minor injury or harm to
the environment and goods.
1.2 SAFETY PRECAUTIONS
Isolate the Main Power Supply to the boiler before removing the cover.
Failing to isolate the device could result in electric shock.
Personal injury from Hot surfaces or Sharp edges within the boiler.
Protection of Main Power Cables.
A result of electric shock or a fire risk could be possible if power cables are damaged
or incorrectly installed
Do not store objects on top of the device.
Injury resulting from falling objects from the device due to vibration.
Damage to surrounding objects, people or pets resulting from falling objects.
Internal damage to the device if objects fall into the unit.
Do not Stand on the device.
Personal injury as a result of falling or damaging boilers fixings and fixtures that may
result in catastrophic failure.
Installation.
The installation must be performed by fully qualified engineers in accordance with
current regulations at the time of installation.
Cleaning.
Make sure to isolate the main power supply to the boiler before cleaning. Clean the
outer case with a damp cloth, Do not use chemical cleaners or abrasive compounds as
this may damage the surface.

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1.3 GENERAL EXPLANATION
The Astro Electric Boiler range provides space heating and Instantaneous hot water
for domestic or light commercial use.
The installation must be performed in accordance with current IEE Wiring
Regulations, Building Regulations, Water Fitting Regulations (England & Wales) or
Water By-laws (Scotland) and all relevant British Standards.
EHC will not be not responsible for damages caused from improper installation and
incorrect use of the appliance.
Make sure the boiler is operated as intended. Any use which does not comply with
the boiler's intended purpose may cause serious injury, death or harm to the
environment and the appliance.
ATTENTION; Only Qualified Engineers & Approved Service Engineers are
recommended for installation and service of the product. Unqualified personnel and
the use of non standard parts can be dangerous and will invalid ate the manufactures
warranty.
1.4 INSTRUCTIONS and BUILDING REGULATIONS
This appliance must be installed in accordance with the following instructions.
The Local Building Regulations
The Building Regulations
The Building Standards, (Scotland-consolidated) Regulations.
Local water bylaws & British Standarts - code of practice.
BS EN 12828
Heating system in buildings design for water-based heating systems.
BS EN 12831
Heating system in buildings method for calculation of the design heat load.
BS EN 14336
Heating system in buildings installation and commissioning of water based heating
systems.
BS7671
Requirements for electrical installations. IEE Wiring Regulations.
BS EN 13831
Closed expansion vessels with built-in diaphragm for installation in water.

1.5 C.O.S.H.H
Materials used in the manufacture of this appliance are non-hazardous and no special
precautions are required when fitting or servicing this appliance.
1.6 PREPARATION
1.6.1 Load Check
A load check should be taken into consideration when installing high output boilers.
1.6.2 Boiler Location
The boiler must be installed onto a wall that will provide an adequate fixing and within an
area that is not subject to frost or damp conditions.
1.6.3 Central Heating Installation
Detailed recommendations are given in BS EN 12828,BS6700 and CP 342-2
Pipes forming part of the useful heating surface should be insulated to prevent any
potential heat loss or frost damage (BS 6700).
Drain valves should be fitted at the lowest point of the system pipe work in an accessible
position.
Drain valves should be in accordance with BS 2879 and copper tube to BS EN 1057 is
recommended.
2. INTRODUCTION
2.1 APPERANCE AND EXTERNAL DIMENSIONS
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2.2 BOILER COMPONENTS
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a. Main heat exchanger
b. Heating elements
c. Actuator Valve
d. Flow manifold
e. DHW temperature NTC sensor
f. Pressure switch
g. Pressure gauge
h. Plate heat exchanger
i. Circulation pump
j. Return manifold
k. 3bar safety valve
l. Electronic flow sensor
m. Expansion vessel
n. PCB Control board
o. Cooling fan
p. Electric terminal
q. CH - NTC sensor
r. Short-circuit thermostat
s. Limit thermostat
t. RCD device
u. Cable gland fixing plate
v. Cable gland
w.Earth connection
x. Float level sensor
y. Manual air vent

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2.3 MAIN FEATURES OF THE BOILER
EHC Fusion Astro electric combination boilers provide central heating by connecting to
panel radiators or underfloor heating systems. The primary circuit is heated via the main
heat exchanger within the boiler and circulated throughout the system by the smart
modulating pump. Fusion Astro boilers provide instantaneous domestic hot water to
supply sinks, wash hand basins & showers within the property.
The DHW is supplied via the boilers plate heat exchanger. When there is a demand for
DHW, the 3 - Way valve is activated firing the system to provide instant Hot Water to the
outlets. In Winter mode, DHW supply is always prioritized.
Note: Due to lower flow rates produced from electric combination boilers,we do not
recommend lower outputs boilers to fill baths. We also recommend the use of low flow
tap outlets that will in turn save water and energy. Flow rates are shown in the table on
page 27.
•EHC Fusion Astro electric combi boiler uses electricity as fuel.
•The device is equipped with many safety functions to provide risk free operation.
•Efficiency 100%
•Eco-friendly, Zero emissions
•Quiet operation
Digital control system
•Error code system
•3 Bar Internal safety valve.
•Pressure Gauge
•Energy efficient ErP Smart pump.
•S/Steel Plate DHW heat exchanger
•Low pressure protection (min 0.7 bar)
•Built-in RCD (short circuit relay) provides electrical protection.
•Internal automatic by-pass system.
•Volt Free Programmer / Thermostat connection.
•NTC Electronic water temperature control system.
•Overheat Limit Thermostat
•Short-Circuit thermostat for increased protection.
•Pump Protection -Anti- Seizure system will operate the pump every 24 hours to
prevent it from sticking when not used for long periods.
•Frost protection.
•Boiler outputs: 12,15,18 & 24kW

3.MOUNTING AND INSTALLATION
3.1 OPENING THE BOX
Open the box as shown above . Cut the cord or remove the staples, fold the box
lids backward and turn the box upside down onto a protected surface. Pull the box
upwards and remove.
3.1.1 Delivery Content
3.2 MOUNTING INSTRUCTIONS
The Boiler must not be installed in Humid/Damp areas such as bathrooms or
buildings that are open to the atmosphere. The location should be clean and dry
with no presence of gases,explosives,flammable materials or chemicals of any
kind.
The boiler must be mounted on a wall capable of carrying the boilers full weight
when fully commissioned (42kg). When the boiler is fixed onto Masonry walls,
use the supplied screws and plugs. When the boiler is fixed onto other wall types
e.g. plasterboard walls, it is recommended that the boiler is secured onto the
timber studs to provide a secure fixing. You can use the supplied screws and
disregard the wall plugs for this type of installation.
Take care when mounting the boiler that you leave the recommended clearances
shown below. This is important for any future maintenance of the unit and
required ventilation.
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Note: Care must be taken when opening and
removing the boiler from its packaging to
prevent any damage.
Handling:
It is advised that two people carry and mount
the boiler onto the wall using all relevant
safety precautions and protective clothing,
foot wear,gloves and goggles must be worn
when appropriate.

3.4 WALL MOUNTING
Note:
The boiler will be approximately 12mm
higher than the mounting plate when
installed. If the boiler is to be mounted
onto a plasterboard wall the plate must be
fixed directly onto the timber frame behind
the plasterboard to ensure the unit has a
secure fixing.
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3.3 MINIMUM CLEARANCES
1. Hold the mounting plate against the
wall at your chosen height parallel to
the floor taking into consideration the
minimum required clearances and
level with a spirit level.
2. Mark the holes.
3. Drill and insert the provided wall plugs.
4. Now fix the mounting plate using the
screws and plugs provided.
5. Hang the boiler on the mounting plate.
400mm
60mm
60mm 450mm
200mm

3.5 HEATING AND HOT WATER CONNECTIONS
•Cold & Hot Water Connections.
The cold water inlet and hot water outlet connections are G 1/2" male thread
connections. Use 2 x 1/2" female to 15mm pipe adapters with an isolation valve fitted
to the cold supply connection. Make sure that the pressure of the mains water does
not exceed 6 Bar. If the Mains Water pressure is more than 6 Bar a pressure
reduction valve must be fitted. The minimum required pressure is 0,8 Bar. For hard
water areas a water softener must be used. Salt softeners must not be used to fill the
heating system.
Note:
Set the correct flow rate for the boiler output as shown in the table on page 27. If the
flow rate is set to high the Hot Water outlet temperature will not be acheived.
•Flow & Return Connections.
Flow & Return connections are G 3/4" male thread. Use 2 x 3/4" female to 22mm pipe
adapters along with 2 x full bore isolation valves to provide good system circulation. A
minimum of 1m of copper pipe must be used on all connections from the boiler. The
boilers are fitted with Wilo smart pumps that can be adjusted if required. Refer to the
pump section below. An external magnetic filter must be used on all installations.
•PRV.
The boilers are fitted with a 3bar pressure relief valve that will automatically activate if
the system pressure is ever increased above 3 bar. The PRV should never be used
as a drain point as this could cause the device to leak.
•Bypass.
When thermostatic valves are used and close due to the room temperatures being
achieved the boilers internal bypass will operate. The automatic by-pass system will
provide the minimum circulation requirement for the heat exchanger.
•Insulation.
We recommend that all pipe-work is insulated where practical. Especially the primary
pipe-work with in a boiler cupboard. This will reduce heat loss and protect the
cupboard from high temperatures.
•System Filling.
A WRAS approved filling loop must be used and installed in such a way that it never
becomes a permanent connection to the mains water and the heating system itself.
The heating system should be filled to 1.5 bar when cold and topped up accordingly
during commissioning and general system maintenance.
8

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•Flushing.
•The primary circuit must be flushed in accordance to BS 7593. The system must
be
flushed to within 10% off mains water PPM YDOXHto ensure that no debris is
trapped in the system.
•Failure to do so may lead to boilerRUFRPSRQHQW failure which will not be
covered by manufacturer's warranty.
•Where existing radiators and pipe-work are used, a power flush must be carried
out and a magnetic filter installedRQWKHUHWXUQSLSHWRWKHERLOHU
•Connections

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FHUQR[RQ03301007750 or Technical 0870 870 0362or further assistance.
3.5.1 BOILER INSTALLATION SCHEMATICS

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3.5.2 CIRCULATION PUMP IMFORMATION
Indicator Lights (Leds)
•Signal display
•LED is lit up in green in normal operation
•LED lights up/flashes in case of fault
•Display of selected control mode Δp-v, Δp-c and
constant speed
•Display of selected pump curve (I, II, III) within the
control mode
•LED indicator combinations during pump venting
function, manual restart and key lock
Press Button
Select control mode
• Select pump curve (I, II, III) within the control mode
Press and hold
• Activate the pump venting function
(press for 3 seconds)
• Activate manual restart (press for 5 seconds)
• Lock/unlock button (press for 8 seconds)
Operating button

Recommended for two-pipe heating systems with radi-
ators to reduce the flow noise at thermostatic valves.
The pump reduces the delivery head to half in the case
of decreasing volume flow in the pipe network.
Electrical energy saving by adjusting the delivery head
to the volume flow requirement and lower flow rates.
There are three pre-defined pump curves (I, II, III) to
choose from.
Recommended for underfloor heating or for large-sized
pipes, applications without a variable pipe network
curve (e.g. storage charge pumps) or
single-pipe heating systems with radiators.
The control keeps the set delivery head constant irre-
spective of the pumped volume flow.
There are three pre-defined pump curves (I, II, III) to
choose from.
Constant differential
pressure Δp-c
(I, II, III)
II
III
I
H/m
Q/m³/h
III
I
II
H/m
Q/m³/ h
Variable differential
pressure Δp-v
(I, II, III)
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Recommended for systems with fixed system resistance
requiring a constant volume flow. The pump runs in
three prescribed fixed speed stages (I, II, III).
Constant speed
(I, II, III)
I
III
II
H/m
Q/m³/ h
Control modes and functions

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Control modes and functions

3.6 ELECTRICAL CONNECTIONS
All electricity connections to the boiler must be made by a fully quailified electrician.
Improper electric connections made by unqualified people may cause failure of
critical components of the boiler and will invalidate the warranty.
DANGER ! Electric Shock Risk
Make sure to isolate the main power supply before starting work on the
boiler.
Secure the main energy supply to prevent from turning on while working on
the boiler.
A) Remove the 2 bottom screws of the front boiler cover.
B) Slide the boiler cover upwards until its released from the boiler chassis.
C) Pull the front boiler cover towards you to disassemble.
3.6.1 Electricity Connection Precautions
•We recommend that a load check is carried out when installing high power boilers.
•All electrical connections must be made by a fully qualified electrician.
•All wiring must be carried out in accordance with current IEE BS7671 wiring
regulations.
•An upgrade to the main fuse of the property may be required.
•This appliance requires supplementary earth bonding across all pipes connected
to the boiler and the main earth terminal within the boiler.
•Surge protection devices should be installed within the installation in-line with
regulation 443 of BS7671.
3.6.2 Removing the Front Boiler Cover
To make electrical connections remove the front cover as shown below.
Always isolate the main power to the unit before removing the front cover..
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3.6.3 Electrical Supply Connections
The main electricity supply connection must be made according to the minimum
cable sizes indicated on the boiler technical label.
The connections are made to the RCD device according to the diagram below.
Single Phase
3-Phase
The cable connections are clearly marked on the cables connected to the RCD device.
•Single Phase L N
•3-phase N L1 L2 L3
•Earth connection is marked with
•Make sure that the power supply cables are tightened between 2.8
-3.5 Nm torque onto the RCD device. Loose connections are
dangerous and can cause fire.
•Do not operate the boiler without an earth connection. Use the
correct cable size and connect it to the earth connection within the
boiler.
•Feed the supply and control cables through the glands at the top of
the boiler and tighten. Where SWA cable is used the plastic gland
should be replaced with a brass SWA gland.
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WARNING
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N L1 L2 L3
L N

Cooling fan for
relay board
RCD device (Single Phase)
L N
Heat exchanger
3-way valve actuator motor
Volt Free Prog / Stat connection
Electric
Terminal
N
Electronic flow sensor
Water pressure switch
Circulation pump
Limit thermostat
Float level sensor
Electric
Terminal
L
DHW temperature NTC sensor
CH temperature NTC sensor
Short-circuit thermostat
Earth connection
RELAY
BOARD
MAIN
BOARD
switches 1
switches 2
3.6.4 Electrical Connection Diagram 230V (Single Phase)
N L
L N N L
Display supply
Relay supply
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