Wolf COB-2 User manual

3066501_201910
GB Operation instructions for contractors
COB-2 / TS OIL CONDENSING BOILER
COB-2 for central heating
TS for central heating with stratication cylinder
English | subject to modications

02 | WOLF GmbH 3066501_201910
Table of contents
1 About this document................................................................................................................ 05
1.1 Scope ......................................................................................................................................................... 05
1.2 Target group ............................................................................................................................................... 05
1.3 Other applicable documents ...................................................................................................................... 05
1.4 Safekeeping of these documents............................................................................................................... 05
1.5 Symbols ..................................................................................................................................................... 05
1.6 Warnings .................................................................................................................................................... 05
1.7 Abbreviations ............................................................................................................................................. 06
2 Safety......................................................................................................................................... 07
2.1 Intended use .............................................................................................................................................. 07
2.2 Safety measures ........................................................................................................................................ 07
2.3 General safety information ......................................................................................................................... 07
2.4 Handover to operator ................................................................................................................................. 08
2.5 Declaration of Conformity........................................................................................................................... 08
3 Description................................................................................................................................ 09
3.1 Layout of COB-2-TS oil condensing boiler................................................................................................. 09
3.2 COB-2 oil condensing boiler components.................................................................................................. 10
3.3 TS stratication cylinder components ........................................................................................................ 11
4 Planning .................................................................................................................................... 12
4.1 Regulations ................................................................................................................................................ 12
4.1.1 Local regulations ........................................................................................................................................ 12
4.1.2 General regulations.................................................................................................................................... 12
4.2 Installation location..................................................................................................................................... 13
4.2.1 Minimum wall clearances to the front and side .......................................................................................... 13
4.2.2 Minimum clearances (above) ..................................................................................................................... 13
4.2.3 Installation site requirements ..................................................................................................................... 14
4.3 Heating system .......................................................................................................................................... 14
4.3.1 Safety equipment ....................................................................................................................................... 14
4.3.2 Heating water ............................................................................................................................................. 15
4.3.3 WOLF accessories - heating system ......................................................................................................... 16
4.4 Fuel supply................................................................................................................................................. 17
4.4.1 Suction line in the single line system ......................................................................................................... 18
4.4.2 Fuel requirements ...................................................................................................................................... 19
4.5 Condensate drain....................................................................................................................................... 19
4.6 Air/ue gas routing ..................................................................................................................................... 19
4.6.1 Installation of the air/ue gas lines............................................................................................................. 20
4.6.2 Overview of connection types .................................................................................................................... 21
4.6.3 Permitted connection types........................................................................................................................ 22
4.6.4 Air/ue gas routing lengths......................................................................................................................... 22
4.6.5 Minimum shaft sizes................................................................................................................................... 24
4.6.6 Notes on connection .................................................................................................................................. 25
4.7 Cascade operation ..................................................................................................................................... 26
4.7.1 Control conguration .................................................................................................................................. 26
4.7.2 Directly heated DHW cylinder .................................................................................................................... 26
4.7.3 Heating system .......................................................................................................................................... 27
4.7.4 Fuel supply................................................................................................................................................. 27
4.7.5 Air/ue gas routing ..................................................................................................................................... 28
5 Installation................................................................................................................................. 30
5.1 Transporting the boiler/stratication cylinder.............................................................................................. 30
5.2 Checking the delivery................................................................................................................................. 30
5.3 Removing / tting the casing ...................................................................................................................... 31
5.4 Position the heat generator and cylinder.................................................................................................... 31
5.5 Installing the safety assembly and pipe assembly ..................................................................................... 32
5.5.1 Installation examples.................................................................................................................................. 33
5.6 Connect the cold water .............................................................................................................................. 34
5.7 Connecting the oil line................................................................................................................................ 35
5.7.1 Connecting the lter/air vent combination.................................................................................................. 35

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Table of contents
5.7.2 Connecting the anti-lift valve ...................................................................................................................... 35
5.8 Connecting the condensate drain .............................................................................................................. 36
5.8.1 Connecting the trap.................................................................................................................................... 36
5.8.2 Connecting the condensate pump ............................................................................................................. 36
5.8.3 Connecting the neutralising box................................................................................................................. 37
5.9 Connecting the balanced ue..................................................................................................................... 38
5.9.1 Installing the balanced ue......................................................................................................................... 38
5.9.2 Installing the ue gas damper (cascade operation only)............................................................................ 40
5.9.3 Installing the roof outlet.............................................................................................................................. 40
5.10 Electrical connection .................................................................................................................................. 40
5.10.1 Power supply.............................................................................................................................................. 40
5.10.2 Terminal box delivered condition................................................................................................................ 41
5.10.3 Removing the terminal box ........................................................................................................................ 41
5.10.4 Installing the terminal box on the wall ........................................................................................................ 42
5.10.5 Connecting the terminal box ...................................................................................................................... 43
5.10.6 Connect the ue gas damper to the power supply (cascade operation only). ........................................... 45
5.11 Connecting the stratication cylinder ......................................................................................................... 45
5.12 Filling the heating system and checking for leaks...................................................................................... 46
5.12.1 Filling the heating system .......................................................................................................................... 46
5.12.2 Checking the hydraulic pipework for leaks................................................................................................. 46
5.13 Checking the pH value ............................................................................................................................... 46
5.14 Control modules ......................................................................................................................................... 46
5.14.1 Selecting a slot........................................................................................................................................... 47
6 Commissioning......................................................................................................................... 48
6.1 Preparation for commissioning................................................................................................................... 48
6.2 Putting the heat generator into service ...................................................................................................... 48
6.3 Plugging in the control module................................................................................................................... 49
6.4 Turning on the heat generator.................................................................................................................... 49
6.5 Conguring the system .............................................................................................................................. 50
6.6 Venting pumps and TS stratication cylinder ............................................................................................. 50
6.6.1 Venting feed/heating circuit pump .............................................................................................................. 50
6.6.2 Vent heating circuit of the TS stratication cylinder.................................................................................... 50
6.6.3 Venting the oil pump................................................................................................................................... 51
6.7 Conguring CO2......................................................................................................................................... 51
6.7.1 Checking the ue system ........................................................................................................................... 51
6.7.2 Test the CO2levels with the casing open ................................................................................................... 52
6.7.3 Setting CO2levels ...................................................................................................................................... 52
6.7.4 Changing the oil pump pressure ................................................................................................................ 53
6.7.5 Testing the CO2 levels with the casing closed............................................................................................ 54
6.8 Commissioning cascade ............................................................................................................................ 54
6.8.1 Setting the eBus address in the programming unit or display module....................................................... 54
6.8.2 Check that the ue gas damper is functioning properly ............................................................................. 54
6.8.3 Check that the ue cascade dampers are free of leaks............................................................................. 55
6.9 Conguring the heat generator .................................................................................................................. 56
6.10 Finishing the commissioning process ........................................................................................................ 56
7 Parameter settings ................................................................................................................... 57
7.1 Parameter list ............................................................................................................................................. 57
7.2 Parameter descriptions .............................................................................................................................. 58
7.2.1 HG01: Burner hysteresis............................................................................................................................ 58
7.2.2 HG07: Run-on time, heating circuit pump .................................................................................................. 58
7.2.3 HG08: Maximum boiler water temperature HTG T-Flowmax ..................................................................... 58
7.2.4 HG09: Burner cycle block .......................................................................................................................... 58
7.2.5 HG10: eBus address of the heat generator ............................................................................................... 59
7.2.6 HG13: Function input E1............................................................................................................................ 59
7.2.7 HG14: Function output A1.......................................................................................................................... 60
7.2.8 HG15: Cylinder hysteresis ......................................................................................................................... 61
7.2.9 HG16: Minimum heating circuit pump rate................................................................................................. 61
7.2.10 HG17: Maximum heating circuit pump rate................................................................................................ 61
7.2.11 HG19: Run-on time, cylinder primary pump............................................................................................... 61

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Table of contents
7.2.12 HG20: Max. cylinder heating time.............................................................................................................. 61
7.2.13 HG21: Minimum boiler temperature BTmin................................................................................................ 61
7.2.14 HG22: Maximum boiler temperature BTmax.............................................................................................. 62
7.2.15 HG23: Maximum DHW temperature .......................................................................................................... 62
7.2.16 HG25: Excess boiler water temperature during cylinder heating............................................................... 62
7.2.17 HG28: Burner operating mode................................................................................................................... 62
7.2.18 HG33: Burner hysteresis runtime............................................................................................................... 62
7.2.19 HG34: eBus feed........................................................................................................................................ 62
7.2.20 HG39: Soft start time.................................................................................................................................. 63
7.2.21 HG40: System conguration ...................................................................................................................... 63
7.2.22 HG42: Header hysteresis........................................................................................................................... 63
7.2.23 HG46: Excess boiler water temperature, header....................................................................................... 63
7.2.24 HG47/49: CO2setting................................................................................................................................. 63
7.2.25 HG56: Input E3 .......................................................................................................................................... 63
7.2.26 HG57: Input E4 .......................................................................................................................................... 63
7.2.27 HG58: Output A3........................................................................................................................................ 63
7.2.28 HG59: Output A4........................................................................................................................................ 63
7.2.29 HG60: Minimum burner hysteresis............................................................................................................. 63
7.2.30 HG61: DHW control ................................................................................................................................... 64
8 Fault ........................................................................................................................................... 65
8.1 Symbols in fault and warning messages.................................................................................................... 65
8.2 Displaying the message history ................................................................................................................. 65
8.3 Dealing with fault and warning messages.................................................................................................. 65
8.4 Fault codes................................................................................................................................................. 65
8.4.1 Fault messages.......................................................................................................................................... 65
8.4.2 Warning messages..................................................................................................................................... 68
9 Decommissioning..................................................................................................................... 69
9.1 Taking the heat generator out of service temporarily ................................................................................. 69
9.2 Putting the heat generator back into service.............................................................................................. 69
9.3 Taking the heat generator out of service in an emergency ........................................................................ 69
9.4 Taking the heat generator out of service permanently ............................................................................... 69
10 Recycling and disposal............................................................................................................ 71
11 Specications ........................................................................................................................... 72
11.1 COB-2 oil condensing boiler ...................................................................................................................... 72
11.2 TS stratication cylinder ............................................................................................................................. 73
11.3 Cascade ..................................................................................................................................................... 73
11.4 Dimensions and connections ..................................................................................................................... 74
11.4.1 Dimensions ................................................................................................................................................ 74
11.4.2 Connections ............................................................................................................................................... 75
11.5 NTC sensor resistances............................................................................................................................. 76
11.6 Hot water-side pressure drop..................................................................................................................... 77
12 Appendix ................................................................................................................................... 79
12.1 Commissioning report ................................................................................................................................ 79
12.2 Wiring diagram ........................................................................................................................................... 80
12.3 HG40: System conguration ...................................................................................................................... 82
12.3.1 System conguration 01............................................................................................................................. 83
12.3.2 System conguration 02............................................................................................................................. 83
12.3.3 System conguration 11............................................................................................................................. 83
12.3.4 System conguration 12............................................................................................................................. 85
12.3.5 System conguration 51............................................................................................................................. 86
12.3.6 System conguration 52............................................................................................................................. 86
12.3.7 System conguration 60............................................................................................................................. 87
12.4 Product data – energy consumption .......................................................................................................... 88
12.4.1 Product datasheet to EU Regulation No. 811/2013 ................................................................................... 88
12.4.2 Technical parameters to EU Regulation No. 813/2013 .............................................................................. 93
12.5 Declaration of Conformity........................................................................................................................... 94

About this document
3066501_201910 WOLF GmbH | 05
1 About this document
► Read this document before you begin working on the appliance.
► Follow the instructions in this document.
Failure to observe these instructions voids any WOLF GmbH warranty.
1.1 Scope
This document contains instructions for the COB-2 and COB-2-TS oil condensing boiler.
1.2 Target group
This document is intended for gas, plumbing, heating and electricity contractors.
1.3 Other applicable documents
COB-2 / COB-2-TS service instructions for contractors
COB-2 / COB-2-TS operating instructions for users
System and operator's log for contractors
Hydraulic System Solutions technical guide for contractors
The documents for all accessory modules and other accessories also apply where relevant.
1.4 Safekeeping of these documents
Documents must be kept in a suitable location and must be available at all times.
The user is responsible for the safekeeping of all documents.
The documents are provided by the contractor.
1.5 Symbols
The following symbols are used in this document:
Symbol Meaning
►An action which must be taken
➠A necessary requirement
✔The outcome of an action
i
Important information regarding the proper use of the heat generator
A reference to other relevant documents
Table 1.1 Meaning of the symbols
1.6 Warnings
Warnings in the text warn you of possible risks before the start of an instruction. The warnings provide
you with information on the possible severity of the risk using a pictogram and a keyword.
Symbol Keyword Explanation
DANGER This means that there is a risk of serious injury or loss of life.
WARNING This means that there is a potential risk of serious injury or loss of life.
CAUTION This means that there is a potential risk of minor to moderate injury.
NOTE This means that material damage may occur.
Table 1.2 Meaning of warnings

About this document
06 | WOLF GmbH 3066501_201910
Layout of warnings
These warnings are laid out as follows:
KEYWORD
Type and source of risk!
Explanation of the risk.
►Action to prevent the risk.
1.7 Abbreviations
BMS Building management system
HC Heating circuit
HCP Heating circuit pump
BDF Boiler drain & ll valve
CW Cold water
AFR Air/ue gas routing (concentric, eccentric or separate)
BFC Balanced ue chimney
PP Primary pump
CPP Cylinder primary pump
HLSC High limit safety cut-out
DHW Domestic hot water
FHP Feed/heating circuit pump

Safety
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2 Safety
► The heat generator may only be worked on by contractors.
► In accordance with VDE 0105 Part 1, work on electrical components may only be carried out by
qualied electricians.
2.1 Intended use
The heat generator may only be used in hot water heating systems in accordance with DIN EN 12828.
The heat generator must not be operated outside of its permitted output range.
A contractor is dened as a qualied and properly trained installer, electrician, etc.
The user is dened as somebody who has been trained to use the heat generator by a specialist.
2.2 Safety measures
Never remove, bypass or otherwise disable any safety or monitoring equipment. Only operate the heat
generator if it is in perfect technical condition. Any faults or damage that impact or might impact safety
must be remedied immediately by a qualied contractor.
► All faulty components of the heat generator must be replaced with original WOLF spare parts.
2.3 General safety information
DANGER
Electrical voltage!
Danger of death from electrocution.
► All electrical work must be performed by a contractor.
DANGER
Insufcientcombustionairsupplyoruegasremoval!
Risk of asphyxiation or severe to life-threatening poisoning.
► Switch OFF the heat generator if you can smell ue gas.
► Open windows and doors.
► Notify a contractor.
CAUTION
Oil leak!
Drinking water may be contaminated by hazardous substances.
► Shut off the oil supply to oil-bearing parts before starting any work.
► Perform a seal inspection on oil-bearing parts after work has nished.
WARNING
Hot water!
Risk of scalding hands from hot water.
►Before working on parts which are in contact with water, allow the appliance to cool to below
40°C.
► Use safety gloves.
WARNING
High temperatures!
Risk of burns on the hands from hot components.
►Before working on an open heat generator, allow the heat generator to cool to below 40°C.
► Use safety gloves.
WARNING
Overpressure on the water side!
Risk of injury due to high overpressure in the heat generator, expansion vessels and sensors.
►Close all valves.
► Empty the heat generator if necessary.
► Use safety gloves.

Safety
08 | WOLF GmbH 3066501_201910
2.4 Handover to operator
► Provide these instructions and the other applicable documents to the operator.
► Instruct the system user how to operate the heating system.
►Make the operator aware of the following:
– Annual inspections and maintenance must be performed by a contractor.
–WOLF recommends concluding an inspection and maintenance contract with a contractor.
– Repair work must be performed by a contractor.
– Use only genuine WOLF spare parts.
– Do not make any technical changes to the heat generator or control components.
– The pH level must be checked after 8 to 12 weeks by a contractor.
– This guide and the other applicable documents must be kept safely in a suitable location and must
be available at all times.
The system user is responsible for the safety, environmental compatibility and energy quality of the
heating system under the German Emission Control Act/Energy Saving Ordinance.
►Inform the operator.
►Refer the operator to the operating instructions.
2.5 Declaration of Conformity
This product complies with European regulations and national requirements.

Description
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3 Description
3.1 Layout of COB-2-TS oil condensing boiler
AB














Fig. 3.1 Layout of COB-2-TS oil condensing boiler
ACOB-2-15/20/29/40 oil condensing boiler
BTS-15/20/29 stratication cylinder
q Condensate pan
w Trap
e Neutralising system (accessory)
r Condensate pump (accessory)
t Circulation
y Cold water
u Domestic hot water
i DHW draw-off at the highest point
o Cylinder heating from above with deector and
divider
a Sensor well for cylinder temperature sensor
s Protective magnesium anode
d Circulation line
f CW stratication pipe
g Drain (in standard delivery)

Description
10 | WOLF GmbH 3066501_201910
3.2 COB-2 oil condensing boiler components












Fig. 3.2 COB-2 oil condensing boiler components
q Automatic air vent valve
w High limit safety cut-out
e Blast tube
r Oil pump motor
t Two-stage oil pump
y Boiler sensor
u Ignition transformer
i Fan
o Differential pressure sensor
a Flue gas temperature sensor
s Water pressure sensor
d Drain valve

Description
3066501_201910 WOLF GmbH | 11
3.3 TSstraticationcylindercomponents














Fig. 3.3 TSstraticationcylindercomponents
q Heating return 1“
w DHW connection ¾“
e Regulated TS stratication pump
r Immersion pipe cylinder sensor
t Plate heat exchanger
y Stratication sensor
u Cylinder primary pump (PP)
i Heating ow 1"
o Cold water connection ¾" (optional accessory)
a Expansion vessel, 8 l (accessory)
s Air vent valve
d Circulation pump (accessory)
f Protective anode (under cover)
g Drain

Planning
12 | WOLF GmbH 3066501_201910
4 Planning
4.1 Regulations
4.1.1 Local regulations
The local regulations must be complied with during the installation and operation of the heating system in
the following respects:
– Siting conditions
– Ventilation and extract air facilities and connection to a chimney
– Electrical connection to the power supply
– Technical regulations for oil storage installations and oil devices
– Regulations and standards regarding the safety equipment of the water heating system
–Drinking water installation
4.1.2 General regulations
The following general regulations, rules and guidelines must be observed during installation:
–DIN 4708 Central heat-water-installations
– (DIN) EN 806 Specications for installations inside buildings conveying water for human consumption
–(DIN) EN 1717 Protection against pollution of potable water in water installations
– (DIN) EN 12831 Heating systems in buildings – Method for calculation of the design heat load
– (DIN) EN 12828 Heating systems in buildings - Design of water-based heating systems
– (DIN) EN 13384 Chimneys – Thermal and uid dynamic calculation methods
– (DIN) EN 50156-1 (VDE 0116 Part 1) Electrical equipment for furnaces and ancillary equipment
– VDE 0470/EN 60529 Degrees of protection provided by enclosures (IP code)
– VDI 2035 Prevention of damage in water heating installations
–Scale formation (Sheet 1)
– Water-side corrosion (Sheet 2)
– Corrosion by fuel gases (Sheet 3)
Germany
The following also apply to installation and operation in Germany:
– Technical regulations for oil installations IWO-TRÖL, as amended
– DIN 1988 Codes of practice for drinking water installations
– DIN 18160 Chimneys
– DWA-A 251 Condensate from condensing boilers
– DWA-A 791 Technical regulations for substances hazardous to water (TRwS)
– TV-DVWK-M115-3 Indirect discharge of non-domestic waste water – Part 3: Indirect discharge
monitoring in practice
– VDE 0100 Erection of power installations with rated voltages below 1000 V.
– VDE 0105 Operation of high voltage systems, general requirements
– KÜO German Federal Sweeping and Inspection Act
– Energy Savings Act (EnEG) and related ordinances:
– EnEV Energy Saving Ordinance (as amended)
–VDE regulations
– Local regulations of your power supply utility
► Installation must be performed by a contractor.
This heating contractor will also be responsible for the proper installation and commissioning of the
heating system. The DVGW Code of Practice G676, the boiler room guidelines or state-issued building
regulations “Guidelines relating to the construction and installation of central boiler rooms and fuel storage
facilities” apply.
Austria
The following apply to installation and operation in Austria:
–ÖVE regulations
– Provisions of the ÖVGW and the corresponding Austrian standards (ÖNORMs)
– Local regulations from building and industry regulatory agencies (generally represented by the
chimney sweep)

Planning
3066501_201910 WOLF GmbH | 13
– Provisions of the regionally applicable building regulations
– The minimum heating water requirements in accordance with ÖNORM H5195-1 must be observed
–ÖVE regulations
– Local regulations of your power supply utility
Switzerland
The following apply to installation and operation in Switzerland:
–SVGW regulations
–VKF regulations
– BUWAL and local regulations must be observed.
4.2 Installation location
The COB-2 and TS are installed adjacent to the wall, which means that a clearance only needs to be
observed at the front.
A surface temperature of 40°C is not exceeded during proper use.
4.2.1 Minimum wall clearances to the front and side
The recommended wall clearances simplify installation, maintenance and servicing.
700
700 700
700
700
COB-2 COB-2
COB-2
TS
TS
700
COB-2TS
Fig. 4.1 Minimum wall clearances [mm]
4.2.2 Minimum clearances (above)
1
COB-2-40: 1900
COB-2-15/20/29: 1800
COB-2-15/20/29: 300
COB-2-40: 400
Fig. 4.2 Minimum clearances (above) [mm]

Planning
14 | WOLF GmbH 3066501_201910
4.2.3 Installation site requirements
Requirements Possible consequences of failing to
follow instructions
Substrate Level
Adequate load bearing capacity
Faults due to air pockets
Ventilation (open ue) Ventilation requirements specied in
TRÖl
Operating the appliance with a leaking
ue gas system presents a risk of
poisoning or asphyxiation due to the
escape of ue gases
Frost protection Adequate ambient temperature System damage due to frost
Vapours and dust No aggressive steam
No signicant dust levels
Appliance must not be installed in
areas like workshops, washrooms,
hobby rooms, etc.
Component damage and/or signicant
soiling of hot water heat exchanger
Combustion air Free from halogenated hydrocarbons Premature ageing of heat exchanger due
to corrosion.
For installation in oil
storage rooms
Comply with relevant national re
safety regulations.
Risk of explosion/re
Table 4.1 Installation site requirements
4.3 Heating system
4.3.1 Safety equipment
– Provide a drain & ll valve at the lowest point in the system.
– The heat exchanger has not been tted with an expansion vessel at the factory.
► The expansion vessel must be sized sufciently, in accordance with DIN 4807.
►Fit the expansion vessel onsite (WOLF accessories range).
WARNING
Risk of explosion due to pressure buildup!
Scalding and physical injury.
► Do not install a shut-off valve between the expansion vessel and the heat generator.
This does not include buttery valves upstream of the expansion vessel.
► Route the discharge pipe of the buttery valve into a drain outlet.
– Make sure that a drain outlet and safety assembly is provided.
The safety assembly from the WOLF accessories range includes an integral 3 bar safety valve.
– A minimum ow rate prevents damage to the hot water heat exchanger as a result of overheating or
steam hammers. This is not required for ow temperatures < 80 °C.
–WOLF recommends using a sludge separator with a magnetite separator.
Deposits in the heating water heat exchanger may lead to boiling noises, a drop in performance or
faults. Using a sludge separator with a magnetite separator protects the heat generator and the high-
efciency pump against magnetic and non-magnetic contamination.
► Install a sludge separator with magnetite separator in the heating return to the heat generator.
–WOLF recommends using an air and microbubble separator.
Microbubbles can cause faults in the heating circuit. An air and microbubble separator is most effective
at the hottest point of the heating circuit.
► Install the air and microbubble separator in the heating ow of the heat generator.

Planning
3066501_201910 WOLF GmbH | 15
4.3.2 Heating water
Limits
Limits (Table 4.3)Measures Possible consequences of
failing to follow instructions
Complied with Use potable water as ll and top-up water. -
Not complied with Flush system with potable water. High level of oxygen ingress
This water must be desalinated
using a dirt lter upstream from the ion
exchanger.
Warranty voided for water-side
system components.
Table 4.2 Treatment of heating water in accordance with VDI 2035
Heating water additives
NOTE
Heating water additives!
Damage to heating water heat exchanger.
►Do not use antifreeze or inhibitors.
NOTE
Corrosion of aluminium components due to pH levels being too high or too low!
Damage to heating water heat exchanger
► The pH value of the heating water must be between 6.5 and 9.0.
► In mixed installations, a pH value of 8.2 to 9.0 must be maintained in accordance with VDI 2035.
Electrical conductivity and water hardness
The limits for conductivity and water hardness are dependent on the specic system volume VA
(VA = system volume / max. rated heating output).
According to VDI 2035, in systems with multiple boilers, use the maximum rated heating output of the
smallest heat generator.
Heating water quality requirement relating to the entire heating system:
Total heating output
VA≤20L/kW
Total hardness1/ total alkaline earths Conductivity2at 25°C
[kW] [°dH] [mol/m³] Cond. [µS/cm]
≤ 50 ≤ 16.8 ≤ 3.0 < 800
50-200 ≤ 11.2 ≤ 2 < 100
Total heating output
VA> 20 L/kW and < 50 L/kW
Total hardness1/ total alkaline earths Conductivity2at 25°C
[kW] [°dH] [mol/m³] Cond. [µS/cm]
≤ 50 ≤ 11.2 ≤ 2 < 800
50-200 ≤ 8.4 ≤ 1.5 < 100
Total heating output
VA≥50L/kW
Total hardness1/ total alkaline earths Conductivity2at 25°C
[kW] [°dH] [mol/m³] Cond. [µS/cm]
≤ 50 ≤ 0.113≤ 0.02 < 800
50-200 ≤ 0.113≤ 0.02 < 100
1 Total hardness conversion: 1 mol/m³ = 5.6 °dH = 10 °fH
2 < 800 µS/cm: high salinity / < 100 µS/cm: low salinity
3 < 0.11 °dH recommended standard, permissible up to limit of < 1 °dH
Table 4.3 Electrical conductivity and water hardness

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Calculation example
System with a COB-2-20
System volume = 800 L
Max. rated heating output for COB-2-20 = 20 kW
Total hardness of untreated potable water Cpotable water = 18 °dH
SpecicsystemvolumeVA
VA= system volume / max. rated heating output
VA= 800 L / 20 kW = 40 L/kW
Maximum permissible total hardness Cmax
See Table 4.3 Electrical conductivity and water hardness
The specic system volume VA is between 20 and 50 L/kW when the total output is < 50 kW.
The total hardness for the ll and top-up water Cmax must therefore be ≤ 11.2 °dH.
If the total hardness of the untreated potable water is too high, some of the lling and top-up water must
be desalinated.
Proportion of desalinated water A
A = 100 % ‒ [(Cmax ‒ 0.1 °dH) / Cpotable water ‒ 0.1 °dH)] • 100 %
A = 100 % ‒ [(11.2 °dH ‒ 0.1 °dH) / 18 °dH ‒ 0.1 °dH)] • 100% = 38 %
38% of the lling and top-up water must be desalinated.
Volume of desalinated water Vtreatment
Vtreatment = A • system volume
Vtreatment = 38% x 800 L = 304 L
At least 304 L of desalinated water must be added when lling the system.
The system can then be topped up with potable water.
Top-up water
The total amount of lling and top-up water over the life cycle of the heat generator must not exceed three
times the nominal volume of the heating system (oxygen ingress!). If a system requires large volumes of
top-up water (e.g. more than 10 % of the system volume per year), the cause must be sought immediately
and the fault remedied.
4.3.3 WOLF accessories - heating system
We recommend making the connection to the heating system with the following parts from the WOLF
accessories range.
Image Item name
Connection kit COB-2 adjacent to wall
2 Cross pieces, each with one connection
2 Clips
1 Corrugated stainless steel pipe 1", length 1300 mm
1 Corrugated stainless steel pipe 1", length 800 mm
1 Silicone grease tube
Connection kit COB-2 with TS adjacent to wall
2 Cross pieces, each with two connections
4 Clips
3 Corrugated stainless steel pipes 1", length 1300 mm
1 Corrugated stainless steel pipes 1", length 800 mm
2 Corrugated stainless steel pipes ¾", length 800 mm
1 Silicone grease tube
1 Trimming set ¾"
1 Trimming set 1"

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Image Item name
COB-2connectionsetadjacenttothewallforaoorstanding
cylinder up to SEM-1-750, SE-2-750 or SEM-2-400
2 Cross pieces, each with two connections
3 Corrugated stainless steel pipes 1", length 1300 mm
1 Corrugated stainless steel pipes 1", length 800 mm
4 Clips
1 Silicone grease tube
6 Flat packings 1"
1 Pipe bend
2 Flat packings 1½" EPDM
1 High efciency pump
1 Adaptor tting G1½ (fem.)
2 Twin connectors G1" (male) - G1" to G1" (male)
1 Elbow with air vent valve
DHW expansion vessel kit for TS
1 Expansion vessel 8 l
1 Cold water connection pipe to the expansion vessel
2 Twin connector ¾"
1 Trimming set ¾"
TS DHW circulation pump accessory set
1 DHW circulation pump, 3 stage
1 Corrugated stainless steel pipe ¾"
1 Trimming set ¾"
Pipe assembly
1 Circulation pump (EE < 0.2)
2 Thermometers in ow and return
2 Ball valves in ow and return
- With/without mixer
- With manifold for 2 or 3 pipe assemblies
Neutralising box
1 Granulate ll
1 Installation accessories
Condensate lifting system with a potential-free alarm output
1 Condensate pump with potential-free alarm output
1 Condensate tank with cover and wall mounting bracket
1 PVC hose 10 mm (6 m long)
1 Non-return valve
1 Condensate inlet adaptor
Table 4.4 Accessories range
For further accessories, such as a safety assembly 1" or wall mounting bracket for pipe assembly, etc.,
see WOLF Heating Systems pricelist.
4.4 Fuel supply
NOTE
Contaminated oil nozzles during maintenance intervals!
Heat generator fault
► Only use lter inserts made of sintered plastic with 25 - 40 μm.
NOTE
Oil lines too large!
Faults due to trapped air
► Use an oil line with an interior line diameter of 4 mm.
► A lter/air vent valve combination with an integrated shut-off valve from the WOLF product range
must be installed.

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4.4.1 Suction line in the single line system
i
Two-line systems must be converted to single line systems.
These older systems are no longer considered state-of-the-art and lead to accelerated oil ageing
and the ingress of air into the oil.
Suitable materials
Use suitable materials for oil lines. In the case of copper pipes, only metallic cutting ring ttings with
support sleeves are permissible. They are a reliable means of preventing air intake.
Max. line lengths
The maximum possible suction line length results from the pressure losses on the pipes and ttings and
the inlet height. The line length includes all vertical and horizontal pipes. The maximum suction line length
recommended by WOLF is 40 m.
+H
-H
AB





Fig. 4.3 Floating suction
AOil pump lower than tank
BOil pump higher than tank
q Oil pump
w Floating suction
e Anti-lift valve
The following table can be used for sizing the suction line length. When sizing the line lengths, the
individual resistances (lter, non-return valve) and six 90° bends are already taken into account.
Type Throughput Internal
diameter of
line
Inlet height H (m)
kg/h mm +4 +3 +2 +1 0 -1 -2 -3
COB-2-15
COB-2-20
COB-2-29
Up to 2.5 4 40 40 40 40 40 35 25 13
COB-2-40 Up to 3.7 4 40 40 40 38 29 22 15 9
Table 4.5 Calculation of inlet height
If the suction height or the maximum suction line length for low-lying tanks is greater than indicated in
Table 4.5 Calculation of inlet height, an oil supply unit with an intermediate vessel is required in the
immediate vicinity of the heat generator. It must be possible to control the oil supply unit independently
of the heat exchanger, i.e. no signal pick-up on the heat generator for this purpose. When connecting a
feed pump in the supply line, the pressure must not exceed 0.5 bar. The oil supply from the intermediate
vessel is driven by the oil pump of the appliance.
Suction
Use oating or raised suction.
Floating suction is not permitted for underground oil tanks or for oil tanks for which a special draw-off
device is prescribed by the manufacturer.

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Permitted negative pressure
The maximum permitted negative pressure in the suction line is 0.3 bar.
Anti-lift valve
With negative pressure controlled anti-lift valves, the negative pressure on the inlet side is increased
considerably. The maximum permitted negative pressure is exceeded. Use an electromagnetically
controlled anti-lift valve to prevent a heat generator fault. This prevents the outgassing of the oil.
4.4.2 Fuel requirements
i
Use low sulphur fuel oil or bio-oil to protect the environment.
Requirement Explanation
Minimum temperature 5 °C, install trace heating to external tank if necessary
Permissible bio-oil
percentages
Up to 10% alternative share –B10– in accordance with DIN V 51603-6
Bio-oil quality EN 14213 at the time that the tank is lled
Bio-oils storage tank Written conrmation from the manufacturer specifying the maximum
permissible FAME (fatty acid methyl ester) proportion
Accessories, e.g. tank ttings, gaskets, lters and oil lines must also be
suitable.
Cleaning the bio-oil tank FAME acts as a solvent in the tank and the oil lines.
For this reason, clean the tank before lling with bio-oil.
Bio-oil storage Bio-oil is a natural product with a shorter shelf life than EL fuel oil.
Bio-oil must be stored at low temperatures (ambient temperature between 5°C
and 20°C) and protected from exposure to direct sunlight (in the case of plastic
tanks in particular).
Up-to-date information indicates that bio-oil should not be stored for longer than
one year.
Table 4.6 Fuel requirements
4.5 Condensate drain
If the condensate is fed directly into the on-site drain:
– Use a exible hose to connect the trap to the on-site drain. Make sure that the incline is sufcient
(drainage height of condensate from trap 260 mm)
– Use a condensate pump if this incline cannot be achieved.
– Make sure that the ventilation is sufcient to avoid the drain pipe affecting the heat generator.
Sulphur content of fuel oil Neutralisation of the condensate
> 50mg/kg Required
< 50 mg/kg This can be omitted after discussing the matter with the local water
authority
Table 4.7 Neutralisation of the condensate
If neutralisation of the condensate is omitted:
– The condensate may only be drained in drain lines in accordance with Code of Practice DWA-A251.
– Mix the condensate with sufcient domestic waste water (at least 20 times the volume of the expected
amount of condensate).
– If this is not possible, neutralisation is required.
4.6 Air/uegasrouting
For safety reasons, use only original WOLF ues and concentric balanced ue systems.
DANGER
Fireandsmokewilltraveltootheroors!
Risk of suffocation, poisoning and burning in the event of exposure to re from outside.
► Take precautions to ensure re resistance.

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4.6.1 Installationoftheair/uegaslines
Air/uegaslines-general
Discuss any installation questions, particular those relating to the installation of inspection covers and
vents, with the local ue gas inspector.
Route the air/ue gas lines over the heat generator in such a way that the displacement device can be
removed.
Minimum clearance above the heat generator:
–COB-2-15/-20/-29: 30cm
–COB-2-40: 40cm
Air/uegasroutingviaroof(typeC33x)
Routing air / ue gas above the roof is permitted under the following conditions:
– Heat generator is located in the attic.
– Heat generator is located in a room where the ceiling is also the roof.
–There is nothing above the ceiling but the roof structure.
If there is nothing above the ceiling but the roof structure, the following applies for the combustion air
supply and the ue from the top edge of the ceiling to the roof skin:
Fire resistance Measures
Required Clad any lines with non-combustible materials which also have this re resistance.
No specic
requirements
Lines must be laid in a shaft made of non-combustible rigid materials or a metal
conduit (mechanical protection).
Air/uegasroutingviashaft
If multiple oors are bridged by the lines for the combustion air supply and the ue, these lines must
be routed in a shaft outside of the installation room. If this is not done, there is no guarantee of any
mechanical protection. Fire resistance must be guaranteed for at least 90 minutes.
Air/uegasroutingviaexistingshaft
Cleaning and inspection not possible from the outlet.Make sure that the following clearance is maintained
between the cleaning and inspection opening in the shaft/channel and the front edge of the ue:
– 2 • diameter of ue
–Maximum 350mm
► Provide sufcient cleaning and inspection apertures.
Ducts which were previously connected to an oil or solid fuel boiler must be cleaned by the chimney
sweep so that no dust remains. If the combustion air is drawn in via the shaft, the prior use can cause
odours in the boiler room.
Dust-free cleaning not possible:
► Use separate air supply.
Securingtheair/uegasroutingoutsideoftheshaft
WARNING
Risk of falling parts!
Physical injury and damage to objects.
► Lines must be secured with brackets every 150 cm.
Secure the air/ue gas routing or ue outside ducts with spacer pipe brackets to prevent the pipe joints
being pulled apart.
Minimum clearance of 50 cm:
–From the connection to the heat generator
– Before or after bends
Protection in winter
WARNING
Risk of water vapour becoming ice and falling off!
Physical injury and damage to objects.
► Use appropriate measures on site to mitigate this risk, e.g. installation of a suitable snow guard.
At low outside temperatures, the water vapour contained in the ue gas may condense and freeze on the
air/ue gas routing system.