andrews COMBIflo 100/300 User manual

M7889
COMBIfl o
Indirect High Effi ciency Boiler & Stainless Steel Storage Water Heater
100/300, 150/300
INSTALLATION OPERATION AND MAINTENANCE MANUAL

Model COMBIflo
100/300
COMBIflo
150/300
Space heating parameters
Condensing boiler - - Yes Yes
Low-temperature boiler(1) - - Yes Yes
B1 boiler - - No No
Cogeneration space heater - - No No
Combination boiler - - Yes Yes
Rate heat output Prated kW 99 147
Useful heat output at rated heat output and high
temperature regime(2) P 4 kW 91.5 136.8
Useful heat output at 30% of rated heat output and low
temperature regime(1) P 1 kW 29.9 43.9
Seasonal
space heating energy efficiency in active
mode (weighted average of useful efficiency) n son % 96.5 95.8
Seasonal space heating energy efficiency n s % 93 94
Useful heat output at rated heat output and high
temperature regime(2) n 4 % 87.7 88.0
Useful heat output at 30% of rated heat output and low
temperature regime(1) n 1 % 98.1 97.2
Auxillary electricity consumption
Full load elmax kW 0.285 0.425
Part load elmin kW 0.099 0.139
Standby mode P SB kW 0.013 0.014
Other items
Standby heat loss P stby kW 0.140 0.170
Ignition burner power consumption P ign kW 0.000 0.000
Annual Energy consumption QHE GJ 283 419
Sound power level, indoors L WA dB 61 62
Emissions of nitrogen oxides NO X mg/k
Wh < 40 < 40
Domestic hot water parameters
Declared load profile 3XL 3XL
Daily electricity consumption Q elec kWh
0.755 0.754
Annual electricity consumption AEC kWh 166 166
Water heating energy efficiency n hw % 75 75
Daily fuel consumption Q fuel kWh
60.395 60.748
Annual fuel consumption AFC GJ 48 48
Weekly fuel consumption with smart controls Q fuel, week,
smart
kWh - -
Weekly electricity consumption with smart controls Q elec, week,
smart
kWh - -
Weekly fuel consumption without smart controls Q fuel, week kWh - -
Weekly electricity consumtion without smart controls Q elec, week kWh - -
Storage volume V l 300 300
Mixed water at 40 °C V40 l 700
Harmonised standards applied EN: 13203-2
(2) High temperature regime means 60°C return temperature at heater inlet and 80°C feed temperature at heater outlet
(1) Low temperature means for condensing boilers 30°C, for low temperature boilers 37°C and for other heaters 50°C
return temperature (at heater inlet)
Specific precautions that shall be taken when the
water heater is assembled, installed or
maintained:
Before any assembly, installation or maintenance the installation
and operation manual has to be read attentively and is followed
Technical Parameters

ANDREWS COMBIfl o 1 GB
Table of Contents
Ref Subject Page
1.0 General & Safety Information
1.1 Description of appliance ............................................................. 2
1.2 For whom is this manual intended? ............................................. 2
1.3 Symbols used in this guide ......................................................... 3
2.0 Safety
2.1 General safety ............................................................................ 4
2.2 Regulations and standards ......................................................... 5
2.3 UKCA & CE Marking ................................................................... 6
3.0 Technical Data
3.1 Dimensions and connections ...................................................... 7
3.2 Performance data ....................................................................... 8
3.3 System Schematic ...................................................................... 9
3.4 Application examples .................................................................. 10
3.5 Wiring diagrams .......................................................................... 16
3.6 Sensor values ............................................................................. 18
4.0 Installation
4.1 Splitting the appliance ................................................................ 19
4.2 Locating the appliance ............................................................... 20
4.3 Fixing to fl oor .............................................................................. 20
4.4 New & existing heating systems ................................................. 21
4.5 Water connections ..................................................................... 22
4.6 Open vent design ...................................................................... 23
4.7 Unvented design ........................................................................ 24
4.8 Secondary return design (DHW circulation pump) .................... 25
4.9 Condensate disposal .................................................................. 25
4.10 Immersion heater ....................................................................... 26
4.11 Mixing valve and actuator control ............................................... 27
4.12 Flue systems and ventilation ...................................................... 28
4.13 Flue terminal positions ................................................................ 30
4.14 Maximum fl ue lengths ................................................................. 31
4.15 Gas connections ......................................................................... 32
4.16 Electrical connections ................................................................. 33
4.17 AGU2.5 Expansion modules ....................................................... 34
4.18 Web server OZW672 ................................................................. 36
4.19 Outside sensor and wired room units ......................................... 38
5.0 Commissioning
5.1 Filling and removal of air ............................................................ 42
5.2 Commissioning of heat engines ................................................. 44
5.3 Conversion to LPG .................................................................... 48
5.4 Frost protection and Legionella .................................................. 49
5.5 Final checks and user handover ................................................ 49
5.6 Fault fi nding ............................................................................... 50
6.0 Maintenance
6.1 Routine Inspection intervals & requirements ............................... 51
6.2 Removing and changing components ........................................ 54
6.3 Component parts list .................................................................. 64
6.4 Component illustrations .............................................................. 66
6.5 Recommended spares requirements ......................................... 69
6.6 Fault code table .......................................................................... 70

ANDREWS COMBIfl o 2 GB
1.1 DESCRIPTION OF APPLIANCE
This Andrews COMBIfl o is a gas fi red, low No×, multi- heat engine cascading boiler system, with an
integrated 5” Low Loss Header for the supply of a low temperature hot water space heating system. The
COMBIfl o range of appliances also features an integrated stainless steel tank and plate heat exchanger
for the supply of hot water.
Fully automatic electronic controls are integrated into the appliance, with a wide range of control and
sensor options available. The controls also provides voltage free outputs for Enable, Burner On, Fault
and 0-10V input for remote BMS use. Access to the controls of the appliance via the Internet and/or mo-
bile phone app, is available through an optional device from Andrews Water Heaters.
Each heat engine module consists of a stainless steel combustion chamber, premix burner, modulating
fan, gas valve, ignition and fl ame detection electrodes and a NTC fl ue sensor for safety supervision.
Each heat engine module is equipped with NTC sensors for precise temperature control on fl ow and re-
turn manifolds. Fully premixed, radiating, modulating burner, integrated with gas valve to deliver precise
gas/air mixture throughout the full modulation range.
Common combustion air intake manifold, takes air from boiler room (type B23 fl ue) or directly from
outside via a combined fl ue system (C13 & C33). An air control non-return fl ap is integrated into the air
supply of each heat engine, to ensure that fl ue products cannot contaminate the air supply, when a heat
engine is not in operation.
The safety and operation functions of each heat engine are managed by micro processor controlled
circuit boards, one for each heat engine. The upper controller also acts as the cascade controller, switch-
ing/modulating the heat engines according to the demand and data from the systems sensors. Control is
performed using comparison parameters between the requested temperature and the global fl ow tem-
perature.
Control Logic:
At full demand, each heat engine is ignited one at a time, until all heat engines are operating at full
output. As fl ow and return temperatures increase, all heat engines will begin to modulate down together,
until all are operating at minimum input rate. As fl ow temperatures begin to approach the calculated set
point, one of the heat engines will stop, leaving the others operating at minimum input rate. This will con-
tinue until all heat engines have stopped and temperature fl ow requirements have been fully satisfi ed.
1.2 FOR WHOM IS THIS MANUAL INTENDED?
This manual is intended for the heating specialist who installs commercial/industrial heating plant and
equipment.

ANDREWS COMBIfl o 3 GB
1.3 SYMBOLS USED IN THIS GUIDE
DANGER!
Indicates serious danger to personal safety and life
DANGER of electric shock!
Indicates serious danger from electricity to personal safety and life
CAUTION!
Indicates a potentially dangerous situation for the boiler and the
environment
INFORMATION
Suggestions to assist the user in implementing instructions in this
guide
ADDITIONAL READING
Reference to additional information in other documents

ANDREWS COMBIfl o 4 GB
2.1 GENERAL SAFETY
SMELL OF GAS
If you smell gas - follow these safety instructions:
- Do NOT turn off or on any electrical switches (including light switches)
- Do NOT smoke
- Do NOT use the telephone
- DO evacuate persons away from the source of the gas smell
- DO close the main gas shutoff valve
- DO open all the windows and doors where the gas leakage has occurred
- DO inform the gas authority or a competent specialist as soon as possible
DANGER
This Andrews Water Heaters product has been designed and manufactured to comply with cur-
rent European standards of safety. However, following an improper use, dangers could arise
concerning the safety and life of the user or of other people, or damage could be caused to the
heater or other objects. This heater is designed to be used in a domestic hot water supply and
storage system. Any other use of this heater will be considered improper. Andrews Water Heat-
ers declines any responsibility for any damage or injuries caused by an improper use. In order to
use the heater according to its designed scope, it is essential to carefully follow the instructions
given in this guide.
DANGER
This heater is not intended for use by persons with reduced physical, sensory or mental capabili-
ties, or lack of experience and knowledge, unless they are given supervision or Instruction con-
cerning the use of it by a person responsible for their safety. Children under the age of 12 years
should not be permitted to use the heater.
DANGER
The installation, adjustment & servicing of this heater must be carried out by a competent person
and installed in accordance with current standards and regulations. Failure to correctly install
or maintain this heater could cause injury to persons or damage to property. The manufacturer
shall not be held liable for any such injury and/or damage.
DANGER
Do not store or use explosive or easily infl ammable material (such as petrol, paint or
paper) in the same room where this heater has been installed.
CAUTION
Water temperature over 50OC can cause burns and in severe cases injury or death. Children,
the elderly and the physically or mentally disabled are most at risk from scald injury. Feel water
before bathing and showering. Temperature limiting devices such as mixing valves should be
installed whenever possible to ensure safe temperatures at outlets
CAUTION
This heater has been designed for use with G20 (natural gas) and G31 (liquefi ed propane gas)
and is manufactured to give an effi cient, safe and long service life. To ensure continued trouble-
free operation of this heater at maximum effi ciency, it is essential that correct installation, com-
missioning, operation and service procedures are carried out strictly in accordance with the
instructions given in this manual.
Only original parts and accessories from the manufacturer may be used on this heater. Using
non-approved parts may compromise the safety of the heater and invalidate any warranty.
In the event of failure and/or suspected faulty functioning of the heater. Switch off the heater and
contact a suitable qualifi ed technician. Do not attempt to make any repairs yourself, unless you
are suitably qualifi ed and competent to do so.
2.0 SAFETY

ANDREWS COMBIfl o 5 GB
CAUTION
If the water system is not in use for periods exceeding 14 days, there is an increased risk of
corrosion on all copper parts and an increase in bacterial growth. Follow the recognised measures
for Anti-legionella in section 5.4.2. to manage this risk
2.2 REGULATIONS AND STANDARDS
This heater must be installed in accordance with relevant Standard Specifi cations, Codes of Practice and cur-
rent Building Regulations, together with any special regional requirements of the Local Authorities, Gas under-
taking and Insurance Regulations for the Electrical Equipment of Buildings. The installation of this heater must
be in accordance with the relevant requirements of:
• Health and safety at work act 1974
• Building regulations 2010
• Electricity at work regulations 1989
• Management of health and safety at work regulations 1998
• Manual handling regulations 1992
• Model water byelaws 1986
• BS 7671 - Requirements for electrical installations, IEE wiring, regulations
• BS 6644 - Specifi cation for the installation of Gas fi red hot water boilers for rated inputs between 70kW
(net) and 1.8 MW
• BS 7074-2 - Applications selection and Installation of expansion vessels and ancillary equipment for sealed
water systems.
• BS 6880:1 Code of practice for low temperature hot water heating systems of output greater than 45kW.
• BS 6880:2 Code of practice for low temperature hot water heating systems of output greater than 45kW.
• BS 6880:3 Code of practice for low temperature hot water heating systems of output greater than 45kW.
• CP 342:2 Code of practice for centralised hot water supply. Buildings other than individual dwellings.
• IM/11 - Flues for commercial and Industrial Gas Fired Boilers and Air Heaters
• IGE/UP/1 - Soundness Testing and Purging Procedure for Non Domestic Installations
• IGE/UP/2 - Gas Installation Pipe work, Boosters and Compressors for Industrial and Commercial Premises
• IGE/UP/10 - Installation of fl ued gas appliances in industrial and commercial premises.
• IGE/UP/16 - Design for Natural Gas installations on industrial and commercial premises with respect to
hazardous area classifi cation and preparation of risk assessments
CAUTION
These manufacturer’s notes must not be taken in any way as over-riding statutory obligations.

ANDREWS COMBIfl o 6 GB
2.3 UKCA MARKING
There is one data plate located on the appliance . This is mounted on the outside of the appliance (left hand
side, next to the document holder)
The UKCA marking documents of this heater confi rms compliance with the essential requirements of the fol-
lowing directives or regulations:
- Gas appliance Appliance (GAR) Regulation 2016/426
- Ecodesign directive for Energy Related Products (ERP) 2009/125/EC
- Electro Magnetic Compatibility (EMC) Directive 2014/30/EU
- Low Voltage (LVD) Directive 2014/35/EU
- Boiler Effi ciency (BED) Directive 92/42/EEC
KEY
1 Type approval designation
2 Gas type and pressure
3 Model Name
4 Heat, gas fl ow & CO ² data
5 Technical data
6 Serial number and year
This manual is an integral and indispensable part of the appliance and it is suggested
that this manual is kept in a safe place for future reference.

ANDREWS COMBIfl o 7 GB
3.1 GENERAL DIMENSIONS & CONNECTIONS
3.0 TECHNICAL DATA

ANDREWS COMBIfl o 8 GB
PERFORMANCE Unit COMBIfl o 100/300 COMBIfl o 150/300
Category gas types I2H G20 @ 20 mbar or I3P G31 @ 37 mbar (5.2mm Orifi ce)
Q Nominal Heat Input net (gross) kW 94.0 (102.2) 140.0 (152.1)
Q Minimum Heat Input net (gross) kW 10.5 (11.3) 10.5 (11.3)
P Nominal Heat Output at 50oc/30oCkW 11.0 - 99.0 11.0 - 147.4
V Maximum Gas Consumption G20 / (G31) m3/h 9.8 / (3.9) 14.5 / (5.7)
Flue gas temperature max (min) oC 85 (50) 85 (50)
CO2 at max output G20 / (G31) % 9.2 +/- 0.1 / (10.2 +/- 0.2) 9.2 +/- 0.1 / (10.2 +/- 0.2)
Max CO at max output ppm 180 180
NOx emission at 0% 02 (EN15420) mg/kWh < 40 < 40
NOx Class class 6 6
Sound level (EN15036-1 Average @ 1m) LAeq 61.1dB 62.0dB
HEATING
Effi ciency heat output at Part load (EN15502-1) net % (gross %) 108.9 (98.1) 107.9 (97.2)
Effi ciency heat output at 50oc/30oC (EN15420) net % (gross %) 105.3 (94.9) 105.3 (94.9)
Effi ciency heat output at Full load (EN15502-1) net % (gross %) 97.3 (87.7) 97.7 (88.0)
Seasonal effi ciency (Building regs Part L2) % 96.1 95.9
PMS Operating pressure max (min) bar 3.5 (0.7) 3.5 (0.7)
Tmax Max permitted operating temperature oC 82 82
Flow / Return connections BSP 2” 2”
Low Loss Header resistance kPa 0.5 0.5
HOT WATER
Tank capacity litres 300 300
Standby losses Watts 140 170
Recovery rate through 50oC l/hr 1,520 2,240
PMS Inlet / Operating pressure max (min) bar 5.5 (0.2) 5.5 (0.2)
In / Out connections BSP M 11/2” M 11/2”
Water return connection BSP M 1” M 1”
ELECTRICAL
Electrical supply voltage / Hz V / Hz 240 / 50 240 / 50
Power consumption - standby W 12.8 13.9
Power consumption - maximum W 516 576
Fuse rating on mains supply A 5 5
Insulation protection rating IP 20 20
FLUE
Flue connection - single mm 130 130
Flue connection - concentric mm 130 / 200 130 / 200
Max fl ue equivalent length - single m 30 30
Max fl ue equivalent length - concentric m 18 18
Flue systems permitted type B23, C13, C33 & C53
Approx fl ue gas volume @ 90oC m3/h 160 242
OTHER CONNECTIONS
Gas BSP F 1” F 1”
Condensate mm 40 40
Immersion Heater BSP 2 1/4” 2 1/4”
Tank drain mm 28 28
WEIGHTS & CLEARANCES
Weight empty (full) kg 290 (608) 320 (641)
Service clearance - rear mm 0 0
Service clearance - right (with immersion) mm 300 (600) 300 (600)
Service clearance - top mm 350 350
Service clearance - left mm 800 800
3.2 PERFORMANCE DATA

ANDREWS COMBIfl o 9 GB
3.3 SYSTEM SCHEMATIC
TEMPERATURE SENSORS B1 Mixed heating circuit B2 Heat engine fl ow B3 DHW cylinder B7 Heat engine return B8 Heat engine fl ue B9 Outdoor 1K B10 Low Loss Header fl ow B36 DHW cylinder primary
CIRCULATION PUMPS Q1 Heat engine Q2 HC1 Heating Q3 DHW Primary Q6 HC2 Heating Q33 DHW Secondary
EXTERNAL CONTROLS RC HC1 Room controller H5 HC2 Room thermostat
MIXING VALVE Y1 Open Valve 230V (1A Max) Y2 Close valve 230V (1A Max)

ANDREWS COMBIfl o 10 GB
3.4 APPLICATION EXAMPLES
Single Heating Circuit (Simple)

ANDREWS COMBIfl o 11 GB
Single Heating Circuit + Immersion + DHW Circulation pump

ANDREWS COMBIfl o 12 GB
Mixer Heating Circuit 1 with Room Control + Heating Circuit 2 + Heating Circuit 3 (Weather Compensation)

ANDREWS COMBIfl o 13 GB
Mixer Heating Circuit 1 + Mixer Heating Circuit 2 + Mixer Heating Circuit 3 (Room + Weather Compensation)

ANDREWS COMBIfl o 14 GB
Heating Circuit - External 0-10V control

ANDREWS COMBIfl o 15 GB
BMS & INTERNET CONNECTIONS

ANDREWS COMBIfl o 16 GB
3.5 WIRING DIAGRAMS
PCB 1

ANDREWS COMBIfl o 17 GB
PCB 2 & 3

ANDREWS COMBIfl o 18 GB
3.6 SENSOR VALUES
3.6.1 10K SENSORS (ALL FLOW/RETURN SENSORS):
Temperature (oC) Resistance
(Ohms)
Temperature
(oC)
Resistance
(Ohms)
-30 175203 50 3605
-25 129269 55 2989
-20 96360 60 2490
-15 72502 65 2084
-10 55047 70 1753
-5 42158 75 1481
0 32555 80 1256
5 25339 85 1070
10 19873 90 915
15 15699 95 786
20 12488 100 677
25 10000 105 586
30 8059 110 508
35 6535 115 443
40 5330 120 387
3.6.2 1K SENSOR (OUTSIDE TEMPERATURE SENSOR):
Temperature (oC) Resistance
(Ohms)
Temperature
(oC)
Resistance
(Ohms)
-20 7578 12 1690
-15 5861 13 1621
-10 4574 14 1555
-5 3600 15 1492
-4 3435 16 1433
-3 3279 17 1375
-2 3131 18 1320
-1 2990 19 1268
0 2857 20 1218
1 2730 21 1170
2 2610 22 1125
3 2496 23 1081
4 2387 24 1040
5 2284 25 1000
6 2186 26 962
7 2093 27 926
8 2004 28 892
9 1920 29 859
10 1840 30 827
11 1763 35 687