Weishaupt WTC-GB 15-B Compact User guide

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact 83309302 1/2018-05

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
83309302 1/2018-05 La 2-196
1 User instructions.............................................................................................................. 6
1.1  Target group.................................................................................................................. 6
1.2  Symbols.......................................................................................................................... 6
1.3  Guarantee and Liability............................................................................................... 6
2 Safety ..................................................................................................................................... 8
2.1  Designated application............................................................................................... 8
2.2  When gas can be smelled ......................................................................................... 8
2.3  What to do if flue gas can be smelled .................................................................... 8
2.4  Safety measures........................................................................................................... 8
2.4.1  Normal operation...................................................................................................9
2.4.2  Electrical connection............................................................................................9
2.4.3  Gas supply..............................................................................................................9
2.5  Disposal ......................................................................................................................... 9
3 Product description ..................................................................................................... 10
3.1  Type key .......................................................................................................................10
3.2  Serial number..............................................................................................................11
3.3  Condensing unit function.........................................................................................12
3.3.1  Water, air and flue gas carrying components.............................................. 12
3.3.2  Electrical components....................................................................................... 13
3.3.3  Safety and monitoring functions..................................................................... 14
3.3.3.1  Flow sensor eSTB / flue gas sensor.......................................................14
3.3.3.2  Multifunction sensor VPT...........................................................................15
3.3.4  Combustion control (System SCOT®) ........................................................ 16
3.3.5  Program sequence............................................................................................. 18
3.4  Fresh water storage tank function..........................................................................20
3.5  Technical data.............................................................................................................22
3.5.1  Approval data...................................................................................................... 22
3.5.2  Electrical data ..................................................................................................... 22
3.5.3  Ambient conditions............................................................................................ 22
3.5.4  Fuels...................................................................................................................... 22
3.5.5  Emissions............................................................................................................. 23
3.5.6  Rating.................................................................................................................... 24
3.5.7  Hydraulic data..................................................................................................... 25
3.5.8  Flue gas system data......................................................................................... 28
3.5.9  EnEV Product Characteristics ........................................................................ 28
3.5.10  Dimensions........................................................................................................ 29
3.5.11  Weight................................................................................................................ 31
3.5.12  Environmental characteristics/Recycling ................................................... 31
4 Installation ........................................................................................................................ 32
4.1  Installation conditions................................................................................................32
4.2  Installing fresh water storage tank .........................................................................33
5 Installation ........................................................................................................................ 34
5.1  Requirements for the heating water ......................................................................34
5.1.1  Water hardness.................................................................................................. 34
5.1.2  Fill water quantity ............................................................................................... 36
5.1.3  Treat the fill and top-up water......................................................................... 37

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
83309302 1/2018-05 La 3-196
5.2  Hydraulic connection ................................................................................................38
5.3  Gas supply ..................................................................................................................40
5.4  Install condensing unit ..............................................................................................41
5.5  Condensate connection...........................................................................................44
5.6  Air supply / flue gas duct .........................................................................................45
5.7  Electrical connection.................................................................................................46
5.7.1  Wiring diagram ................................................................................................... 47
5.7.2  Bus installation.................................................................................................... 50
5.7.3  Connect external pump .................................................................................... 51
5.7.4  Connect fresh water storage tank WAS 100.............................................. 52
5.7.5  Connect fresh water storage tank WAS…Power.................................... 53
6 Operation .......................................................................................................................... 54
6.1  Operational display....................................................................................................54
6.2  Display and operating unit .......................................................................................55
6.3  Display..........................................................................................................................56
6.4  Favourites level ...........................................................................................................57
6.5  User level .....................................................................................................................57
6.5.1  Info......................................................................................................................... 58
6.5.2  System operating mode.................................................................................... 59
6.5.3  Heating circuits................................................................................................... 60
6.5.4  Domestic hot water  .......................................................................................... 62
6.5.5  Statistic................................................................................................................. 62
6.5.6  Settings ................................................................................................................ 63
6.6  Expert level ..................................................................................................................64
6.6.1  Info......................................................................................................................... 65
6.6.1.1  System ...........................................................................................................65
6.6.1.2  WTC............................................................................................................... 66
6.6.1.3  Remote control ............................................................................................69
6.6.1.4  Hydraulic .......................................................................................................69
6.6.1.5  Heating circuits............................................................................................70
6.6.1.6  Domestic hot water.....................................................................................72
6.6.1.7  Fault memory................................................................................................73
6.6.2  WTC...................................................................................................................... 74
6.6.2.1  Boiler controller............................................................................................74
6.6.2.2  Boiler circuit.................................................................................................. 75
6.6.2.3  Combustion ..................................................................................................76
6.6.3  Remote control ................................................................................................... 77
6.6.4  Hydraulic .............................................................................................................. 78
6.6.4.1  De-couple .....................................................................................................78
6.6.5  Heating circuits................................................................................................... 79
6.6.5.1  Heating circuit settings..............................................................................79
6.6.5.2  Control behaviour........................................................................................80
6.6.5.3  Mixer control.................................................................................................81
6.6.5.4  Screed program........................................................................................... 82
6.6.6  Domestic hot water............................................................................................ 84
6.6.6.1  DHW control ................................................................................................84
6.6.6.2  Legionella protection..................................................................................85
6.6.6.3  Circulation.....................................................................................................86

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
83309302 1/2018-05 La 4-196
6.6.7  Service WTC ...................................................................................................... 86
6.6.7.1  Servicing........................................................................................................86
6.6.7.2  Input measurement .....................................................................................87
6.6.7.3  Output measurement..................................................................................88
6.6.7.4  Control measurement.................................................................................90
6.6.7.5  Combustion chamber pressure ...............................................................91
6.6.8  Output test........................................................................................................... 93
6.6.8.1  WTC............................................................................................................... 93
6.6.8.2  EM heating circuit .......................................................................................93
6.6.9  Commissioning menu........................................................................................ 94
6.6.9.1  System ...........................................................................................................94
6.6.9.2  Device list......................................................................................................95
6.6.9.3  Hydraulic .......................................................................................................96
6.6.9.4  Heating circuits............................................................................................97
6.6.9.5  Inputs/outputs..............................................................................................98
6.6.9.6  WTC............................................................................................................... 99
6.6.9.7  Factory setting .......................................................................................... 100
6.7  Chimney sweep function....................................................................................... 101
7 Commissioning............................................................................................................102
7.1  Prerequisite .............................................................................................................. 102
7.1.1  Check soundness of gas valve train............................................................103
7.1.2  Check gas connection pressure...................................................................104
7.1.3  Set type of gas on gas combi valve.............................................................104
7.2  Adjusting the condensing unit ............................................................................. 105
7.3  Check soundness of flue gas system ................................................................ 117
7.4  Adjust capacity ........................................................................................................ 117
7.5  Calculate combustion heat rating ....................................................................... 118
8 Shutdown........................................................................................................................119
9 Servicing..........................................................................................................................120
9.1  Condensing unit service........................................................................................ 120
9.1.1  Notes on servicing ...........................................................................................120
9.1.2  Components......................................................................................................121
9.1.3  Removing and refitting burner surface........................................................122
9.1.4  Replacing electrodes ......................................................................................123
9.1.5  Cleaning the heat exchanger.........................................................................124
9.2  Fresh water storage service ................................................................................. 126
9.2.1  Notes on servicing ...........................................................................................126
9.2.2  Service plan.......................................................................................................126
9.2.3  Clean fresh water storage tank.....................................................................127
9.2.4  Removing and refitting magnesium anode.................................................128
9.2.5  Non-return valve (WAS…Power) ..............................................................129
10 Troubleshooting ..........................................................................................................130
10.1  Procedures for fault conditions......................................................................... 130
10.2  Warning codes ..................................................................................................... 132
10.3  Fault codes ............................................................................................................ 135
10.4  Operating problems............................................................................................. 141

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
83309302 1/2018-05 La 5-196
11 Accessories ...................................................................................................................144
11.1  Externally powered anode .................................................................................. 144
12 Technical documentation.......................................................................................146
12.1  Hydraulic versions ................................................................................................ 146
12.1.1  WTC version KI..............................................................................................146
12.1.2  WTC version KP............................................................................................148
12.2  Control options ..................................................................................................... 150
12.2.1  Constant flow temperature..........................................................................150
12.2.2  Weather compensated control...................................................................150
12.2.3  Room temperature dependent control .....................................................150
12.2.4  Weather compensated/Room control ......................................................151
12.2.5  De-couple control..........................................................................................151
12.3  Control options ..................................................................................................... 152
12.4  Circulation pump .................................................................................................. 153
12.5  Inputs/outputs ....................................................................................................... 154
12.6  Factory setting engineer level............................................................................ 156
12.7  Factory setting heating circuit type .................................................................. 159
12.7.1  Factory setting heating curve......................................................................160
12.8  Factory setting time programs........................................................................... 161
12.9  Wiring diagram WEM-FA-G device electronics........................................... 162
12.10  Sensor variables................................................................................................. 163
12.11  Remote access to heating system via internet ........................................... 164
13 Project planning...........................................................................................................165
13.1  Expansion vessel and system pressure........................................................... 165
13.2  Weishaupt Energy Management WEM........................................................... 166
14 Spares...............................................................................................................................168
15 Notes .................................................................................................................................190
16 Key word index ............................................................................................................191

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
1 User instructions
83309302 1/2018-05 La 6-196
1 User instructions
Translation of original
operating instructions
This manual forms part of the equipment and must be kept on site.
Carefully read the manual prior to working on the unit.
1.1 Target group
The manual is intended for the operator and qualified personnel. They should be
observed by all personnel working with the unit.
Work on the unit must only be carried out by personnel who have the relevant train-
ing and instruction.
In accordance with EN 60335-1 the following requirements apply
This appliance can be used by children 8 years and above as well as by persons
with limited physical, sensory or mental capacities or lack of experience and know-
ledge, provided they are supervised or have been instructed regarding the safe use
of the appliance and understand the resulting danger. Children must not play with
the appliance. Cleaning and operator maintenance must not be carried out by chil-
dren without supervision.
1.2 Symbols
DANGER
Immediate danger with high risk.
Non observance can lead to serious injury or death.
WARNING
Danger with medium risk.
Non observance can lead to environmental damage,
serious injury or death.
CAUTION
Danger with low risk.
Non observance can cause damage to the equip-
ment and injury to personnel.
Important information
Requires direct action
Result after an action
Itemisation
… Range of values
1.3 Guarantee and Liability
Guarantee and liability claims for personal and equipment damage are excluded, if
they can be attributed to one or more of the following causes:
non approved application,
non-observance of the manual,
operation with faulty safety equipment,
continual operation despite a fault,
improper installation, commissioning, operation and service,
repairs, which have been carried out incorrectly,
the use of non original Weishaupt parts,
force majeure,
unauthorised modifications made to the unit,

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
1 User instructions
83309302 1/2018-05 La 7-196
the installation of additional components, which have not been tested with the
unit,
changes to the combustion chamber,
unsuitable fuels,
defects in the inlet lines.
on non diffusion tight heating circuits without system separation.

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
2 Safety
83309302 1/2018-05 La 8-196
2 Safety
2.1 Designated application
The unit is suitable for:
Warm water heating circuits in closed systems to EN12828,
a flow rate of maximum:
WTC 15: 1300 l/h
WTC 25: 2200 l/h
The fresh water storage tank is suitable for the heating of fresh water in accordance
with TrinkwV, with a minimum conductivity of more than100µS/cm at25°C water
temperature.
The combustion air must be free from aggressive compounds (e. g. Halogens) and
free from contaminants (e.g. dust) sein. If the combustion air in the boiler room is
contaminated, increased cleaning and servicing will be required. In this case the
appliance should be operated room air independent.
The unit should only be used in enclosed rooms.
The installation room must comply with local regulations.
Improper use could:
endanger the health and safety of the user or third parties,
cause damage to the unit or other material assets.
2.2 When gas can be smelled
Avoid open flames and spark generation, for example:
do not operate light switches,
do not operate electronic equipment,
do not use mobile telephones.
Open doors and windows.
Close gas isolating valve.
Warn the inhabitants, do not ring door bells.
Leave the building.
Inform the heating contractor or gas supplier from outside of the building.
2.3 What to do if flue gas can be smelled
Switch off unit and turn of the system.
Open doors and windows.
Notify your heating contractor or Weishaupt Customer Service.
2.4 Safety measures
Safety relevant fault conditions must be eliminated immediately.
Components, which show increased wear and tear or whose design lifespan is or
will be exceeded prior to the next service should be replaced as a precaution
[ch.9.1.2].
The design lifespan of the components is listed in the service plan [ch.9.2.2].

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
2 Safety
83309302 1/2018-05 La 9-196
2.4.1 Normal operation
All labels on the unit must be kept in a legible condition.
Stipulated settings, service and inspection work should be carried out at regular
intervals.
Only operate the unit with its cover closed.
Do not touch moving parts during operation.
2.4.2 Electrical connection
For work carried out on live components:
Observe the accident prevention instructions DGUVRegulation3 and adhere to
local directives,
tools in accordance with EN 60900 should be used.
2.4.3 Gas supply
Only the gas supply company or an approved agent may carry out installation, al-
teration and maintenance work on gas appliances in buildings and properties.
Pipework must be subject to a combined load and valve proving test and/or us-
ability testing relative to the pressure range intended, e. g. DVGW-TRGI, work-
sheet G 600.
Inform the gas supply company about the type and size of plant prior to installa-
tion.
Local regulations and guidelines must be observed during installation, e. g.
DVGW-TRGI, worksheet G 600; TRF Band 1 and Band 2.
The gas supply pipework should be suitable for the type and quality of gas and
should be designed in such a way that it is not possible for liquids to form, e. g.
condensate. Observe vaporisation pressure and vaporisation temperature of li-
quid petroleum gas.
Use only tested and approved sealing materials, whilst observing all process in-
formation.
Re-commission the appliance when changing to a different type of gas.
Carry out soundness test after each service and fault rectification.
2.5 Disposal
Dispose of all materials and components in a safe and environmentally friendly way
at an authorised location. Observe local regulations.

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 10-196
3 Product description
The gas condensing unit WTC Compact consists of a condensing boiler and a
drinking water storage tank.
3.1 Type key
Condensing boiler
Example: WTC-GB 15-B vers. K
WTC Range: Weishaupt Thermo Condens
G Fuel: Gas
B Type of construction: floor standing
15 Ratings size: 15 kW
B Construction
Vers. K Version: Compact
Fresh water storage
Example: WAS 115 Power/Bloc-P/B
WAS Series: Weishaupt Aqua storage tank
115 Size: 115
Power Version: external heat exchanger and pump
Bloc cubic design
P Platform for heat exchanger
B Construction

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 11-196
3.2 Serial number
The serial number on the name plate identifies the product. This is required by
Weishaupt's customer service department.
Condensing boiler
1
2
1Additional name plate
2Name plate
Ser.No.
Fresh water storage
1
1Name plate
Ser.No.

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 12-196
3.3 Condensing unit function
3.3.1 Water, air and flue gas carrying components
Image: WTC-GB 15-B vers. K
4
12
3
9
0
w
q
567
8
1Quick action vent valve
2Flue gas connection
3Expansion vessel 18 litres / 0.75 bar
4Expansion vessel fill valve
5three-way valve
6Speed controlled circulation pump
7Pressure gauge system pressure
8Siphon
9Condensate outlet
0Safety valve 3 bar
qIntake sound attenuator
wHeat exchanger

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 13-196
3.3.2 Electrical components
Image: WTC-GB 15-B vers. K
1
3
567
9
0
w
e
8
4
2
q
1Flow sensor eSTB
2Display and operating unit (system device)
3Device electronics WEM-FA-G with electrical connection and unit fuse
4Fan
5Actuator three-way valve
6Flue gas sensor
7Speed controlled circulation pump
8Multifunction sensor VPT
9Gas combi valve
0Ignition unit
qIgnition electrode
wFlow sensor multifunction sensor VPT
eIonisation electrode

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 14-196
3.3.3 Safety and monitoring functions
3.3.3.1 Flow sensor eSTB / flue gas sensor
Flow sensor eSTB
The fuel supply is shut off and the pump run-on is activated if the temperature ex-
ceeds 95 °C (W12). The appliance restarts automatically if the temperature drops
below the target supply value for 1minute.
If the temperature exceeds 105 °C, the fuel supply is shut off and the pump run-on
is activated. The system goes to lockout (F11).
Flow temperature increase eSTB (gradient)
If the flow temperature increases too fast, the appliance is switched off (W14). If
the warning occurs several times in succession, the system goes to lockout
(F14). This function is only activated at a temperature of > 45 °C.
Differential temperature flow eSTB / flue gas
The appliance is switched off if the difference between the flow temperature and
the flue gas temperature exceeds a preset value (W15). If the warning occurs sev-
eral times in succession, the system goes to lockout (F15). When approaching
this value, first the pump capacity is increased and then the burner capacity is re-
duced.
Flue gas sensor
If the flue gas temperature exceeds 120 °C (factory setting), the fuel supply is shut
off and the pump run-on is activated (F13). On proximity to the safety temperature
the burner capacity will be reduced, at a difference of 5 K (115 °C) the burner
shuts down (W16) [ch.6.6.2.1].

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 15-196
3.3.3.2 Multifunction sensor VPT
The multifunction sensor determines and monitors:
volumetric flow,
system pressure,
flow temperature,
return temperature.
Volumetric flow
If the volumetric flow drops below 60l/h, the appliance switches off (W10),
(not in heating mode, when the condensing unit supplies the heating circuit dir-
ectly).
System pressure
If the system pressure drops below the value of parameter 2.2.7 minimum
system pressure warning, a waring message is issued (W36). If the system
pressure drops below 0.5 bar, the appliance switch off (F36). If the pressure in-
creases above 0.5 bar, the appliance automatically restarts [ch.6.6.2.2].
Differential temperature flow eSTB / flow VPT
If the difference between the flow temperature eSTB and the flow temperature VPT
exceeds a preset value, the appliance is switched off (W18). If the warning occurs
several times in succession, the system goes to lockout (F18).
Differential temperature flow VPT / return VPT
If the difference between flow and return temperature exceeds a specified value,
the appliance is switched off for at least 3minutes. If the shutdown occurs several
times in succession, a warning is issued (W17). When approaching this value, first
the pump capacity is increased and then the burner capacity is reduced.
Flow temperature increase VPT (gradient)
If the flow temperature increases too fast, the appliance is switched off (W19). If
the warning occurs several times in succession, the system goes to lockout
(F19). This function is only activated at a temperature of > 45 °C.

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 16-196
3.3.4 Combustion control (System SCOT®)
The appliance is equipped with an electronic combustion control.
The combustion control is carried out via ionisation electrode. Depending on the
measured ionisation current, the gas volume is regulated to the amount of air avail-
able.
If excess air is reduced, the combustion temperature and therefore the ionisation
current increases. The maximum ionisation current (Io max) is achieved at excess air
of 0 % (λ=1.0).
Calibration procedures regularly determine the maximum ionization current (Io max).
Excess air is calculated from this maximum value. The setpoint of the ionisation cur-
rent (Io set) is set so that the following O2 content is available across the entire
modulation range.
O2 content
Natural Gas approx. 5.0 % (λ=1.29)
Liquid Petroleum Gas approx. 5.3 % (λ=1.31)
Example
Io max
Io soll
=1.0 1.28
3
2
1
1Air number [λ]
2Ionisation current
3Turndown ratio
Calibration
Calibrations are carried out:
by dynamically predefined operating hours,
by dynamically predefined burner starts,
following power outage,
following the occurrence of certain faults (e.g. F21, W22, etc.).
Calibration can be carried out manually via the output measurement or with the
commissioning wizard.
Manual calibration is mandatory when replacing the following components:
ionisation electrode,
burner surface,
WEM-FA-G device electronics,
gas combi valve.
During calibration the CO content briefly (approx. 2 s) increases above 1000 ppm.

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 17-196
O2 correction
Following calibration via the output measurement or using the commissioning wiz-
ard, a new O2 curve is generated.
The entire curve can then be moved in parallel via the O2 total correction
at max load, thus optimising the O2 content; the WTC drives to 100% capacity.
Using O2 correction up to 50% at min load the O2 content can also be
optimised in the lower load range.
Example
5.2
5.1
5.0
4.9
4.8
4.7
4.6
4.5
5.3
5.4
2
1
3 4
7
6
5
1Burner capacity
2O2 content [%]
3minimum load
4maximum load
5O2 curve following calibration
6O2 curve following O2 total correction at max load
7O2curve following O2 correction up to 50% at min load

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 18-196
3.3.5 Program sequence
Ignition speed
The fan stars at heat demand1 and drives to ignition speed2.
Ignition
Ignition3 starts once the ignition speed has been stabilised. The gas valves4
open. A flame is formed.
Safety time
Following the safety time (3.5seconds)5 ignition is switched off.
Flame stabilisation
If a flame signal6 is transmitted, the flame stabilisation time7 will follow.
Forced partial load
In operating mode heating, forced partial load8 is carried out first. For the dura-
tion of the delay time, the heating capacity is limited, forced partial load is omitted
for DHW loading.
Operation
The internal unit temperature regulator sets the speed setpoint for the fan9 within
the programmed load limits.

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 19-196
Post-purge
Following every normal shut down, after faults and after the return of the power
supply, the fan is operated at the post-purge speed0.
7
5
6
4
3
2
8
9
0
1

Installation and operating instruction
Gas condensing unit WTC-GB 15-B Compact and WTC-GB 25-B Compact
3 Product description
83309302 1/2018-05 La 20-196
3.4 Fresh water storage tank function
The condensing boiler can be combined with the following fresh water storage
tanks:
Pipe coil tank WAS 100 Bloc-P/A
Stratified tank WAS 80 Power/Bloc-P/A
Stratified tank WAS 115 Power/Bloc-P/B
WAS 100 Bloc-P/A
The fresh water is heated via a plain ended pipe heat exchanger.
DHW loading is initiated, when the temperature at the DHW sensor (B3) drops be-
low the DHW setpoint temperature minus the switch differential.
1
2
3
4
7
6
5
1Funnel siphon with outlet
2Magnesium anode
3DHW sensor (B3)
4Outlet tap
5Fresh water inflow device
6Plain ended pipe heat exchanger
7Inspection flange