Stuart Turner Mikrofill ETHOS 70 Guide

ETHOS 70, 90, 110 & 130 WALL MOUNTED CONDENSING BOILERS
TECHNICAL DOCUMENTATION
2023/01 REV. 01
CONDENSING BOILERS

TABLE OF CONTENTS
01. Technical Data 04 07. Operating Instructions 22
Operation
02. Dimensions 05 Controls
Boiler Module 23
03. Safety Guidelines 06 PCB Symbol Key
Conditions Switching On the Appliance 24
General Guidelines Switching Off the Appliance
Service 07 Information Display 25
General Restrictions DHW Operation
Heating Operation
04. Description 07 Displaying Information
General Table Parameter List
Working Principle and Design History Mode 26
Application Features 08 Possible Error Codes
Main Components 09 Possible Error Codes continued. 27
Bottom Connections
Boiler Control 10 08. Commissioning 28
Safety Aspects General
Reference Value for Maximum Load
05. Delivery & Transport 11 Reference Value for Minimum Load
Delivery Maximum Load Adjustment 29
Transport Minimum Load Adjustment
Moving Setting the CO2Value for the ETHOS Range 30
Access Requirements Conversion from Natural Gas to Propane 31
06. Installation 12 09. Cascade Set-Up 31
Regulations Auto Detection Mode
Installation Area Cascade Test Mode 32
Mounting - Solid Walls
Mounting - Non-Load Bearing Walls 10. Maintenance 33
Installation Guidelines Safety
Ventilation 13 Servicing Schedule
Gas Connection Gas Valve and Venturi 34
Water Connections Fan and Burner Assembly (ETHOS 70) 35
Electrical Connections Fan and Burner Assembly (ETHOS 90, 110 and 130) 36
0 - 10 V Control Pump / Pump Head 37
Internal Controls Breakdown (Main PCB) 14 Setting / Checking of Electrode and Probe Gaps 38
Internal Controls Breakdown (Control Fascia) 15
External Controls Breakdown (Din Rail) 11. Component List 39
Flue Connection 16 Casing and Electrical Components
Flue Gas Outlet and Air Inlet Pipe Core Components (ETHOS 70) 40
Flue Adaptor Installation Core Components (ETHOS 90, 110 and 130) 41
Flue Gas Data 17
Flue Length 12. Conversion Formulae & Factors 42
Calculation of Diameter and Length
Resistance Table 18 13. Notes 44
Condense Connections 19
Safety Valve Connection
Hydraulic System
Pump Characteristics 20
Shut-Off Valves 21
Valves (Boilers in Cascade Arrangement)
Water Flow Protection Device
Water Pressure
System Expansion Vessel
Water Pressure Protection Device
Water Temperature
Water Quality
Water Hardness 22
TECHNICAL DOCUMENTATION 03

TECHNICAL DATA
GENERAL
Dimensions (Height x Width x Depth) mm 905 x 530 x 475 905 x 530 x 675
Model ETHOS 70 ETHOS 90 ETHOS 110 ETHOS 130
Water Content of Appliance litre 7.0 8.8 10.7 12.4
Weight (Empty) kg 67 91 102 116
Flow / Return Connections BSP ¾” 1¼” 1¼” 1¼”
Gas Connection BSP ¾” ¾” ¾” ¾”
Flue Connection mm 80 100 100 100
Air Supply Connection mm 80 100 100 100
Concentric (Optional) mm 80/125 110/150 110/150 110/150
Power Consumption W 369 369 369 419
Electrical Supply V 230 230 230 230
Frequency Hz 50 50 50 50
Fuse Protection A 6 6 6 6
Maximum Fan Speed RPM 6600 6700 6750 5300
Minimum Fan Speed RPM 1500 1400 1550 1200
HEATING PERFORMANCE
Nominal Heat Input (Nett) kW 12.5 - 70.0 16.5 - 90.0 20.0 - 110.0 24.0 - 130.0
Nominal Heat Output at 80/60°C kW 12.2 - 68.4 16.0 - 87.5 19.4 - 106.9 23.6 - 127.7
Nominal Heat Output at 50/30°C kW 13.7 - 76.8 17.8 - 97.2 21.6 - 118.8 25.9 - 140.4
Maximum Gas Consumption
G20 m3/hr 7.4 9.4 11.5 13.6
G25 m3/hr 8.6 10.9 13.4 15.8
G31 m3/hr 2.9 3.7 4.5 5.3
TECHNICAL DATA
Flue Gas Dew Point °C 52 52 52 52
Flue Temperature at 80/60°C (at ambient temperature of 20°C) °C 75 75 75 75
Flue Material Temperature Class T 120 T 120 T 120 T 120
Permitted Maximum Resistance of Flue System* Pa 140 140 200 200
Condensation pH Value 3.0 - 5.5 3.0 - 5.5 3.0 - 5.5 3.0 - 5.5
Maximum CH Flow Temperature °C 90 90 90 90
CH Water Pressure (Minimum / Maximum) bar 0.5 - 4.0 0.5 - 6.0 0.5 - 6.0 0.5 - 6.0
Minimum / Maximum Gas Pressure
G20 mbar 17 - 20 17 - 20 17 - 20 17 - 20
G25 mbar 17 - 20 17 - 20 17 - 20 17 - 20
G31 mbar 30 - 50 30 - 50 30 - 50 30 - 50
ENVIRONMENTAL DATA
Flue Gas CO2Content
G20 % 8.4 8.4 8.4 8.4
G25 % 8.4 8.4 8.4 8.4
G31 % 9.5 9.5 9.5 9.5
NOXLevels mg/kW 33.0 33.0 33.0 33.0
Maximum Efciency (Nett Non-Condensing) % 97.7 97.2 97.2 98.2
Maximum Efciency (Nett Condensing) % 109.7 108.0 108.0 108.0
Seasonal Efciency % 96.79 95.46 95.46 95.63
*With this resistance value the heat output will remain within the specications indicated on the dataplate; if the resistance is higher, the
heat output will be reduced.
04 TECHNICAL DOCUMENTATION

DIMENSIONS
▲ FIGURE 01. DIMENSIONS OF THE ETHOS WALL MOUNTED BOILERS.
ETHOS 70 ETHOS 90 ETHOS 110 ETHOS 130
A mm 120 140 140 140
B mm 80 100 100 100
C mm 125 95 95 95
D mm 475 475 675 675
E mm 65 65 65 75
F mm 125 125 125 115
G in ¾” 1¼” 1¼” 1¼”
H in ¾” ¾” ¾” ¾”
• All dimensions are in millimetres unless otherwise specied.
• Data may deviate slightly due to fabrication tolerances.
• We reserve the right to make changes without prior notication.
530
905
110 70
180
65 EF
GG H
245 A
C
D
Ø B
≈ 55
TECHNICAL DOCUMENTATION 05

SAFETY GUIDELINES
CONDITIONS
Mikroll Systems Ltd. shall not be liable for any damages caused by non-compliance with this manuals
instructions. Only original parts must be used for service purposes.
GENERAL GUIDELINES
The appliance is not intended for use by persons (including children) with reduced mental, physical or sensory
capabilities, or lack of experience or knowledge, unless they have been given supervision or instruction
concerning the use of the appliance by a person responsible for their safety.
It is a statutory requirement that all gas appliances are installed in accordance with the manufacturers
instructions and all regulations in force. All instructions should be fully read before installing or using the
appliance. All installations should be carried out by competent persons as described in the Gas Safety
(Installation and Use) Regulations i.e. Gas Safe registered and holding current certication.
The manufacturers instructions MUST NOT be taken in any way as overriding statutory obligations.
This boiler has been tested and certied to comply with all necessary European directives, latest building
regulations and efciency requirements, is CE marked and complies with;
• 2009/142/EC Gas Appliance Directive.
• 2014/30/EU Electromagnetic Compatibility Directive.
• 2014/35/EU Low Voltage Directive.
This boiler should be installed in compliance with;
• Building Regulations.
• Building Regulations (Scotland-Consolidated).
• Building Regulations (Northern Ireland).
• The Health and Safety at Work Act.
• Gas Safety (Installation and Use) Regulations.
• Water Fittings Regulations or Water By-laws in Scotland.
• Local Water Company By-laws
The boiler should not be modied in any way. Any modications will invalidate the gas approval and invalidate
the warranty.
ATTENTION: HIGH VOLTAGE!
Before opening the boiler casing for maintenance or servicing, the 230 VAC main supply
to the boiler must be disconnected!
06 TECHNICAL DOCUMENTATION

SAFETY GUIDELINES
DESCRIPTION
SERVICE
Should you require any assistance during installation or in the unlikely event of a product failure please do not
hesitate to contact our technical department on 03452 60 60 20.
GENERAL RESTRICTIONS
Mikroll products should always be used, installed and maintained in accordance with the statutory
requirements, specications and standards applicable to these installations. Mikroll cannot be held
responsible for any losses or damage whether direct or consequential that have arisen as a result of incorrect
or poor installation.
WARNING!
Particular attention must be given to the safety guidelines as non-compliance will render
the warranty void and may constitute an illegal installation.
GENERAL
The Mikroll ETHOS wall mounted boilers are environmentally friendly gas red heating boilers with a modulation
range between approximately 10% and 100% of their maximum output. The appliances have low NOXand
CO emission, which satises the most stringent environmental requirements.
The ETHOS range has received UKCA and CE approval for all relevant countries
and has been registered under the Product Identication Number 86CN59.
The boilers may be used on both open (type B23) as well as room sealed (type C13, C33, C43, C53, C63 or
C83) systems.
The boiler is delivered fully wired, fully assembled, tested and preset complete with emissions report.
WORKING PRINCIPLE AND DESIGN
Air is drawn in as required, via a variable speed fan. The gas valve measures the negative pressure (draught)
in the venturi and modulates the gas valve in response. The gas and air is then thoroughly mixed in the correct
ratio in the fan housing and red directly into the burner.
The boiler management system compares the actual water ow temperature to the required water
temperature. The management system computes the load required and adjusts the fan speed. This is a
continual process during operation.
The heat transfer takes place in a stainless steel double heat exchanger block. The burner res into the primary
heat exchanger whilst the second heat exchanger (condenser) is connected downstream in such a manner
that the condense water cannot enter the primary heat exchanger, both heat exchangers consist of several
smooth pipes in the form of a coil and are connected using stainless steel water distribution manifolds.
TECHNICAL DOCUMENTATION 07

DESCRIPTION
The design of the boiler incorporates the following:
• Full Operation and Fault Diagnostics via LCD.
• Control / High Limit Sensors.
• Integral Boiler Shunt Pump.
• Integral Safety Relief.
• Integral Weather Compensation (Optional External Sensor Required).
• Frost Protection.
• Pressure Read Out.
• Compatible with most External BMS Options.
08 TECHNICAL DOCUMENTATION

DESCRIPTION
ETHOS 70: ETHOS 90, 110 AND 130:
BOTTOM CONNECTIONS:
0107
14
07 01
02
09
04
04
1010
09
13 05
11 11
13
06
02
03
06
05
08
14
08
12
12
16 1815 17 19
MAIN COMPONENTS:
01 Air Inlet Connection 08 Gas Valve and Venturi
02 Air Inlet Tube 09 Grundfos UPML 25-105 130 PWM
03 Air Vent Valve* 10 Heat Exchanger and Burner Package
04 Combustion Fan 11 Ignition Transformer
05 Controls Housing 12 Oxygen Depletion Sensor
06 Flue Gas Temperature Sensor 13 Pressure Relief Valve
07 Flue Outlet Connection 14 Sealed Air Inlet Trap (located behind Air Inlet Tube)
BOTTOM CONNECTIONS:
15 Flow Connection 18 Condense Outlet
16 Condense Syphon 19 Return Connection
17 Gas Connection
* Only present on ETHOS 90, 110 and 130 Heat Exchangers.
TECHNICAL DOCUMENTATION 09

DESCRIPTION
BOILER CONTROL
If there is a heat demand, and if all necessary conditions have been fullled and all safety devices are
satised, the boiler will start. This heat requirement will arise if:
• the ow temperature of the boiler is less than the required ow temperature.
• the frost protection has been triggered independently of the operating conditions.
The boiler control unit adjusts the boiler output by changing the fan speed such that the desired temperature
is attained and maintained. The actual ow temperature is controlled within 4°C of the target temperature.
SAFETY ASPECTS
The following safety devices are installed on the boiler:
• Temperature Monitoring System.
• High Limit Temperature Monitoring System.
• Limit Temperature Monitoring System.
• Flame Monitoring by means of Ionisation Measurement.
• Fan Speed Monitoring.
• Flow Monitoring using a combination of Flow and Return Water Temperature Sensor Readings.
If one of these safety systems is activated, the boiler will go to an interlocking or lockout condition and will
be switched off. Lockout conditions can only be reset by pressing the reset button, after rectifying the fault.
10 TECHNICAL DOCUMENTATION

DELIVERY & TRANSPORT
DELIVERY
The boiler is delivered fully assembled, tested and packed.
• Check the boiler for damage upon receipt.
• Check whether the items delivered are correct and in accordance with the items ordered.
TRANSPORT
The packing should only be removed after transportation.
MOVING
Each boiler is packed in its own carton. Refer to the technical data for dimensions and weights in order to
work safely within the Health and Safety guidelines when handling these products.
ACCESS REQUIREMENTS
The dimensions are such that all ETHOS wall mounted boilers can be transported through a standard doorway.
TECHNICAL DOCUMENTATION 11

INSTALLATION
REGULATIONS
The appliance should be installed by a competent installer in accordance with the applicable national and
local standards, rules and regulations (please refer to pages 06 and 07 for safety guidelines).
INSTALLATION AREA
• Due to the low noise level, there should be no need for additional sound insulation of the room.
• Due to its compact design, very little installation space is required (see clearance dimensions
below).
• The location options for the boiler are increased because it is suitable for both open ued and
room sealed operation.
MOUNTING - SOLID WALLS (BRICK OR BLOCK)
Fix the mounting bracket with suitable xings using a spirit level and ensuring that there is sufcient clearance
around the boiler to allow for access and ue installation.
MOUNTING - NON-LOAD BEARING WALLS (STUDDING OR LIGHTWEIGHT PARTITIONS)
We recommend the use of a purpose designed mounting frame which is available from Mikroll Systems Ltd.
or alternatively we can supply drawings for site construction of the same.
INSTALLATION GUIDELINES
The following guidelines should be complied with;
• The device should be installed in a frost free room due to the risk of freezing of the condensate
drain.
• The built-in protection system is activated when the temperature of the central heating water falls
below 5°C.
• Ensure that there is sufcient room around the device for maintenance and the replacement of
components if necessary.
The recommended minimum clearances are as follows:
• 750mm to the front (to allow free space for movement).
• 400mm above.
• 250mm below.
• 25mm at the sides.
Please note that with the side clearance listed above, direct ue runs will not meet the minimum required
distance in-between the terminals. 100mm side clearance will give this required distance between the two
terminals.
12 TECHNICAL DOCUMENTATION

INSTALLATION
VENTILATION
The ventilation of the installation room should conform to current gas regulations.
GAS CONNECTION
The gas connection is located on the bottom of the appliance (see page 09). It should be installed by a
competent installer in accordance with the applicable national standards.
A suitable isolation valve should be installed for each boiler and should be in an accessible position. Care
should be taken when sizing the pipework to ensure the supply is sufcient for the maximum load operation
of the boiler.
The pressure on the inlet side of the appliance should be reduced to 20 mbar for natural gas (G20) and no
more than 50 mbar for propane (G31). Under full load conditions the measured gas pressure at the gas valve
should be no less than 17 mbar for natural gas (G20) and 30 mbar for propane (G31).
WATER CONNECTIONS
The boiler is designed for sealed systems only and should not be used for open vented systems. For information
and sizing of sealed system equipment, please refer to our pressurisation management brochure.
It is recommended that manually operated valves should be installed between the boiler ow and return
connections and the system.
It is also recommended that the ow and return pipes are securely xed with brackets. This prevents damage
and makes maintenance easier.
ELECTRICAL CONNECTIONS
The electrical connections should be installed by a competent installer in accordance with applicable
national standards.
The appliance is fully wired in accordance with the electrical diagrams delivered with the appliance.
Electrical terminal connections are located at the base of the boiler and are protected by a metal enclosure.
Access to the terminals is gained by removing the boiler front panel and unscrewing the lid from the enclosure.
Suitable cable entry points are supplied in the form of cable glands.
The appliance is suitable for a 230 V 50 Hz power supply with live / neutral / earth and is polarity sensitive. The
installer should use a local two pole isolating switch with a contact opening of at least 3mm in the 230 V supply
to the boiler. A permanent earth must also be installed. In order to prevent problems due to electromagnetic
radiation, screened cables should be used for all control wiring between the boiler and external management
systems. The screening should be earthed on both sides in accordance with current EMC directives.
As the boiler incorporates electrical equipment there is an obligation to the installer to ensure that the boiler
is correctly earthed.
0 - 10 V CONTROL
If using the 0 - 10 V control, please ensure that the voltage is driven down to 0 V to disable the boiler(s) and
that the 0 - 10 V connection to terminals 12 and 13 is not broken; if broken, the boiler can re on low re due
to a voltage differential between terminals 12 and 13. Please note that the 0 - 10 V control will override the
boiler set point and control via the burner modulation i.e. 10 V = 100%. Please ensure that the control voltage
is modulated to prevent the boiler over shooting the required set point.
TECHNICAL DOCUMENTATION 13

INSTALLATION
INTERNAL CONTROLS BREAKDOWN (MAIN PCB)
01 02 03
04 05 06
01 02 03 04 05
06 07 08 09 10
01 02
03 04
01
02
03
04
05
06
07
08
09
10
11
12
13
14
01
02
03
04
05
06
07
08
01
02
03
04
05
06
01
02
03
04
01
02
03
04
0510
09
08
07
06
X18 F00 F01
X16 X17
X13
X12
X15
X14
X11
X02 X01 X00
• X00 Pin 01: Power to Main PCB
• X00 Pin 02: Power to Main PCB
• X01 Pin 01: Boiler Run Signal
• X01 Pin 02: Pump
• X01 Pin 03: 240 V Output*
• X01 Pin 04: 240 V Output*
• X01 Pin 05: Fan Mains
• X01 Pin 07: Pump
• X01 Pin 08: 240 V Output*
• X01 Pin 10: Fan Mains
• X02 Pin 01: Transformer
• X02 Pin 02: Transformer
• X02 Pin 05: Gas Valve Rectied
• X02 Pin 06: Gas Valve Rectied
• X11 Pin 01: AC Fan Interface
• X11 Pin 02: AC Fan Interface
• X11 Pin 04: PWM Supply
• X11 Pin 06: AC Fan Interface
• X11 Pin 07: AC Fan Interface
• X11 Pin 10: PWM Supply
• X13 Pin 01: Pressure Sensor
• X13 Pin 02: Pressure Sensor
• X13 Pin 03: Oxygen Depletion Sensor
• X13 Pin 04: DHW Sensor
• X13 Pin 05: Return Sensor
• X13 Pin 06: Supply Sensor
• X13 Pin 08: Pressure Sensor
• X13 Pin 09: Oxygen Depletion Sensor
• X13 Pin 11: DHW Sensor
• X13 Pin 12: Return Sensor
• X13 Pin 13: Supply Sensor
• X14 Pin 01: Flue Sensor
• X14 Pin 05: Flue Sensor
• X15 Pin 01: Main PCB to Control Fascia
• X15 Pin 02: Main PCB to Control Fascia
• X15 Pin 03: Main PCB to Control Fascia
• X15 Pin 04: Main PCB to Control Fascia
• X15 Pin 05: Main PCB to Control Fascia
• X15 Pin 06: Main PCB to Control Fascia
▲ FIGURE 02. TOP VIEW OF MAIN PCB.
* Used to either power additional pump or motorised valve.
14 TECHNICAL DOCUMENTATION

INSTALLATION
INTERNAL CONTROLS BREAKDOWN (CONTROL FASCIA)
X06
X01X04
X03
X05
• X01 Pin 01: Control Fascia to Main PCB
• X01 Pin 02: Control Fascia to Main PCB
• X01 Pin 03: Control Fascia to Main PCB
• X01 Pin 07: Control Fascia to Main PCB
• X01 Pin 08: Control Fascia to Main PCB
• X01 Pin 09: Control Fascia to Main PCB
• X03 Pin 02: Communication with Master
• X03 Pin 04: Communication with Master
• X03 Pin 05: Communication with Master
• X04 Pin 01: 0 - 10 V DC Input
• X04 Pin 02: OpenTherm
• X04 Pin 03: OpenTherm
• X04 Pin 04: External Sensor
• X04 Pin 05: External Sensor
• X04 Pin 06: 0 - 10 V DC Input
• X04 Pin 07: CH Cascade Sensor
• X04 Pin 08: CH Cascade Sensor
• X04 Pin 09: Room Thermostat
• X04 Pin 10: Room Thermostat
• X05 Pin 01: Alarm Output
• X05 Pin 02: Alarm Output
• X05 Pin 05: Reset
• X05 Pin 06: Reset
• X06 Pin 02: Communication with Slave
• X06 Pin 03: Communication with Slave
• X06 Pin 04: Communication with Slave
▲ FIGURE 03. TOP VIEW OF CONTROL FASCIA.
EXTERNAL CONTROLS BREAKDOWN (DIN RAIL)
▲ FIGURE 04. FRONT VIEW OF DIN RAIL.
ALive, Earth and Neutral: Incoming Supply GConnections 12 and 13: 0 - 10 V DC Input[5]
BConnections 1 and 2: Room Thermostat[1] HConnections 14 and 15: OpenTherm
CConnections 3 and 4: External Sensor IConnections 16, 17 and 18: Communication with Slave
DConnections 5 and 6: DHW Thermostat[1] JConnections 19, 20 and 21: Communication with Master
EConnections 7, 8 and 9[2]:DHW Output[3] KConnections 22 and 23: CH Cascade Sensor
FConnection 11[4]:Alarm Output LConnection 24[4]:Boiler Run Signal
[1] Volt Free Connection (UNDER NO CIRCUMSTANCES MUST VOLTAGE BE APPLIED TO THESE CONNECTIONS).
[2] 240 V Output in no DHW Load Condition (0.8 A).
[3] Used to either power additional Pump or Motorised Valve (0.8 A).
[4] 240 V Output (0.8 A).
[5] Factory tted link, do not remove unless utilising 0 - 10 V control.
TECHNICAL DOCUMENTATION 15

INSTALLATION
FLUE CONNECTION
During installation, a choice can be made between a ‘room sealed’ or ‘open ued’ system. The standard two
pipe (eccentric) connections can be easily converted using the Mikroll adaptor.
The ue gas discharge outlet and air intake system should be installed by a competent installer according
to applicable national and local standards and specications. When using multiple boilers on a single
application, care should be taken to ensure compliance with the Clean Air Act.
• Type B23:
• Type C13:
• Type C33:
• Type C43:
• Type C53:
• Type C63:
• Type C83:
Open type appliance without draught stabiliser, air supply from the room, ue gas
discharge outlet above the roof.
Room sealed appliance, connected to concentric air supply / ue discharge through
the wall.
Room sealed appliance, connected to concentric air supply / ue discharge through
the roof.
Room sealed appliances in cascade, connected to a common concentric air supply /
ue discharge at the appliance.
Room sealed appliance, connected to a seperate air supply and ue discharge pipe,
opening into different pressure areas.
Room sealed appliance, sold without related connecting and / or discharge ttings.
Room sealed appliances in cascade, connected to seperate air supplies but common
ue discharge through the roof.
FLUE GAS OUTLET AND AIR INLET PIPE
The air inlet and ue gas outlet pipes may be single wall, smooth or exible, and be made of:
• Aluminium (air inlet only)
• Plastic
• Stainless Steel
Always consider the large resistance when using exible material, and also consider condensate formation
due to the suction of cold air.
ETHOS 70 ETHOS 90 ETHOS 110 ETHOS 130
Diameter of Air Inlet mm 80 100 100 100
Diameter of Flue Gas Outlet mm 80 100 100 100
▲ FIGURE 05. DIAMETERS OF AIR INLET AND FLUE GAS OUTLET CONNECTIONS.
The connection for the air supply is on top of the boiler.
The air supply pipe should be air tight. This is to prevent the suction of ‘false air’. Horizontal components in the
air supply should be installed sloping in the direction of the supply opening.
FLUE ADAPTOR INSTALLATION
Please ensure the ue adaptor, when used, is tted in the correct orientation as shown below:
16 TECHNICAL DOCUMENTATION

INSTALLATION
FLUE GAS DATA
The ue gas outlet is located on top of the appliance and is designed for direct connection to a corrosion
resistant ue pipe.
The ue gas discharge pipe to be used should be air tight and water tight at the joints and connections, or
should be seamless. Horizontal components in the ue pipe should be installed sloping in the direction of the
appliance (minimum of 25mm per metre).
Care should be taken when making joints to ensure that the seals are not damaged and the joints must be
sited to enable access / inspection (GasSafe TB 008 Ed. 2.1).
When using a cascade ue system, non-return valves may be required. Please contact our technical
department on 03452 60 60 20 for further information.
A direct connection to a brick chimney is not permissible unless a suitable liner is installed.
The following table gives the ue gas data for all types:
ETHOS 70 ETHOS 90 ETHOS 110 ETHOS 130
Average Flue Gas Temperature at Full Load °C 70 70 70 70
Quantity of Flue Gas at Full Load m3/h 109.9 141.3 171.7 204.1
kg/s 0.031 0.040 0.049 0.058
Maximum Permissable Flue Resistance Pa 140 140 200 200
▲ FIGURE 06. FLUE GAS DATA / LOAD 100% / FLOW TEMPERATURE 80°C / RETURN TEMPERATURE 60°C.
FLUE LENGTH
Since the boiler is equipped with a ‘premix burner’ with a fan, an over pressure is created in the boiler. This
over pressure is sufcient to overcome the resistance of the burner, the heat exchanger and the chimney.
The back pressure on the boiler depends on:
• the resistance of the ue pipe.
• the degree of cooling of the combustion gases.
• the resistance of the discharge outlet.
The degree of cooling of the combustion gases depends on the following:
• the insulation value of the ue.
• the ambient temperature.
• the ue system and outlet.
There is a maximum over pressure of around 1.4 mbar (140 Pa) for the ETHOS 70 and 90 and 2.0 mbar (200 Pa)
for the ETHOS 110 and 130 in the boiler for the ue gas discharge system.
The maximum draught permissible is 0.2 mbar (20 Pa), this should be checked with the ue warm and boilers
not ring. If the draught is above this then ue stabilisers are recommended.
CALCULATION OF DIAMETER AND LENGTH
For the calculation and control of the inner diameter of a discharge system with mechanical discharge,
please refer to the applicable national and local standards and regulations.
TECHNICAL DOCUMENTATION 17

INSTALLATION
RESISTANCE TABLE
By using either concentric or the two pipe system, different ue lengths can be achieved. In case a concentric system is used, its length
should not exceed 12 metres.
CONCENTRIC FLUE SYSTEM mm RESISTANCE SYSTEM (Pa)
Model ETHOS 70 ETHOS 90 ETHOS 110 ETHOS 130
Vertical Terminal 80/125 65.0 - - -
Horizontal Terminal 80/125 79.7 - - -
Straight Pipe / m 80/125 9.3 - - -
45° Bend 80/125 12.1 - - -
90° Bend 80/125 14.6 - - -
Vertical Terminal 110/150 - 72.6 94.1 143.4
Horizontal Terminal 110/150 - 70.0 90.7 138.3
Straight Pipe / m 110/150 - 7.3 9.8 14.5
45° Bend 110/150 - 10.1 13.2 19.9
90° Bend 110/150 - 21.3 29.4 42.7
TWO PIPE SYSTEM
Air Inlet
Straight Pipe / m 80 4.9 - - -
45° Bend R = 0.5 D 80 6.8 - - -
90° Bend R = 1.0 D 80 8.1 - - -
Flue Gas Outlet
Vertical Terminal 80 36.0 - - -
Horizontal Terminal 80 19.0 - - -
Straight Pipe / m 80 8.9 - - -
45° Bend R = 0.5 D 80 12.4 - - -
90° Bend R = 1.0 D 80 14.7 - - -
Air Inlet
Straight Pipe / m 100 - 1.7 2.4 3.4
45° Bend R = 0.5 D 100 - 1.9 2.7 3.8
90° Bend R = 1.0 D 100 - 8.4 11.7 16.6
Flue Gas Outlet
Vertical Terminal 100 - 29.0 35.0 42.0
Horizontal Terminal 100 - 12.0 18.0 25.0
Straight Pipe / m 100 - 3.1 4.0 6.1
45° Bend R = 0.5 D 100 - 3.6 4.5 7.0
90° Bend R = 1.0 D 100 - 15.4 19.5 30.2
▲ FIGURE 07. FLUE DISCHARGE RESISTANCE.
Example of Calculation for the ETHOS 70 boiler:
Concentric 45° Bend x 2
Concentric 90° Bend x 1
Concentric Pipe 80/125mm, Vertical 2m + Horizontal 1m = Total 3m Concentric Straight Pipe
Vertical Terminal 80/125mm
Concentric 45° Bend:
Concentric 90° Bend:
Concentric Pipe 80/125mm:
Vertical Terminal 80/125mm:
Total Resistance:
2 pcs
1 pcs
3m
2 x 12.1
1 x 14.7
3 x 9.3
Resistance
24.2 Pa
14.7 Pa
27.9 Pa
65.0 Pa*
138.6 Pa
Total resistance is 138.6 Pa, so the boiler output is not changed by the resistance (lower than 140 Pa) and the total concentric
length is less than the maximum allowed 12 metres.
* Vertical terminal length includes 1 metre length.
18 TECHNICAL DOCUMENTATION

INSTALLATION
CONDENSE CONNECTIONS
The boiler includes an anti syphon condense trap enabling the condense pipework to be taken directly to
drain. The condense water is slightly acidic (pH 3.0 - 5.5) and should be run in a standard drain pipe material,
e.g. acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), polyvinyl chloride (PVC), cross-linked polyvinyl
chloride (PVC-C) or unplasticised polyvinyl chloride (PVC-U).
The condensate pipe should ideally run and terminate internally to a soil stack or waste pipe. Alternatively,
the condensate can be discharged in to the rainwater system or a purpose-made soakaway. Whichever
method is used must conform to applicable national and local standards and regulations. All connecting
drainage pipework should have a fall of at least 2.5° to the horizontal, or approximately 25mm per metre of
pipe run. If the drainage pipe has external run it should be kept to a minimum length with a minimum diameter
of 22mm and be insulated in order to minimise the effects of freezing. It should be noted that connection of
a condensate pipe to a drain may be subject to building controls.
SAFETY VALVE CONNECTION
The discharge pipe from the safety valve shall be self draining and terminate in a visible position where the
discharge cannot result in hazard to any person or to the plant. The size of the discharge pipe shall be no less
than the nominal size of the valve outlet.
HYDRAULIC SYSTEM
The minimum required water circulation over the boiler should be maintained at all times (equivalent to ΔT
25°K at full load). The minimum required water circulation should not be adversely affected by the use of
valves, non-return valves, systems in which several boilers are connected to a common distribution pipe etc.
The maximum water ow is achieved at ΔT 15°K.
ETHOS 70 ETHOS 90 ETHOS 110 ETHOS 130
ΔT 20°K Nominal Flow Rate (Q) m3/h 3.00 3.86 4.71 5.57
Boiler Resistance Nominal Flow (R) kPa 45.0 24.5 22.5 31.0
Pump
Data
Pump Head at Nominal Flow (Q) kPa 82.0 66.0 52.0 40.0
Available Head at Nominal Flow (Q) kPa 37.0 41.5 29.5 9.0
Maximum Power Consumption* W 140 140 140 140
* Maximum power consumed is given in Pump Position 03.
▲ FIGURE 08. WATER FLOW QUANTITY AND PUMP DATA FOR THE WALL MOUNTED ETHOS RANGE.
The boiler has a pump control circuit. When the boiler is enabled, the pump is switched on. If the boiler is
disabled, the pump will continue to run for a few minutes. The standard run on time is two minutes, but this
can be adjusted.
TECHNICAL DOCUMENTATION 19

INSTALLATION
UPML 25-105 130 PWM
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Q [m³/h]
0
2
4
6
8
10
[m]
H
0
20
40
60
80
100
[kPa]
p
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4
Q [l/s]
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
Q [m³/h]
0
20
40
60
80
100
120
140
[W]
P1
ELECTRICAL DATA: 1 x 230 V, 50 Hz
SPEED P1[W] I1/1 [A]
Minimum 3 0.04
Maximum 140 1.1
DIMENSIONAL DRAWINGS AND CONTROL BOX POSITIONS (IN MILLIMETRES)
95
130
50
64
131
22
27 112
20 TECHNICAL DOCUMENTATION