Viessmann VITOTRONIC 300 GW2 Quick guide

1
VITOTRONIC 300
Installation and
Service Instructions
Vitotronic 300, Model GW2
Outdoor-reset logic digital boiler and
heating circuit control unit
Certified as a component part
of Viessmann boilers only
Read and save these instructions
for future reference.
IMPORTANT
for use by heating contractor
5285 941 - 01 06/2015
Please file in Service Binder

General information
2
Safety, Installation and Warranty Requirements
Please ensure that this manual is read and understood before commencing installation. Failure to comply with the issues
listed below and details printed in this manual can cause product/property damage, and/or severe personal injury. Ensure all
requirements below are understood and fulfilled (including detailed information found in manual subsections).
Licensed professional heating
contractor
The installation, adjustment, service,
and maintenance of this equipment
must be performed by a licensed
professional heating contractor.
Please see section
entitled “Important
Regulatory and
Installation
Requirements.”
Product documentation
Read all applicable documentation
before commencing installation. Store
documentation near boiler in a readily
accessible location for reference in the
future by service personnel.
For a listing of
applicable literature,
please see section
entitled “Important
Regulatory and
Installation Requirements.”
Advice to owner
Once the installation work is complete,
the heating contractor must familiarize
the system operator/ultimate owner
with all equipment, as well as safety
precautions/requirements, shut-down
procedure, and the need for
professional service annually before
the heating season begins.
Warranty
Information contained in
this and related product
documentation must be
read and followed. Failure
to do so renders warranty
null and void.
Safety Terminology
The following terms are used throughout this manual to bring attention to the presence of potential hazards or important
product information. Please heed the advice given!
Helpful hints for installation,
operation or maintenance which
pertain to the product.
5285 941 - 01
Indicates an imminently hazardous
situation which, if not avoided, will
result in death, serious injury or
substantial product / property damage.
DANGER Indicates an imminently hazardous
situation which, if not avoided, could
result in substantial product/property
damage, serious injury or loss of life.
WARNING Indicates an imminently hazardous
situation which, if not avoided, may
result in minor injury or product /
property damage.
WARNING
IMPORTANT

General information
3
Product Information
Vitotronic 300, Model GW2
For installation in or mounting on
Viessmann boilers only.
Applicable to the following control
units
Order No. 7134 555, 7143 156, 7511 362 from
Serial No. 7143 000 
Order No. 7134 555, 7143 156, 7511 362 from
Serial No. 7187 101 
Order No. 7134 555, 7143 156, 7511 362 from
Serial No. 7248 248 
5285 941 - 01

Index
4
Page
General information Safety Requirements 2..........................................................................
Product information 3............................................................................
Heating system types System types for modulating boilers 6...........................................
System types for condensing boilers 12..........................................
Installation Overview of electrical connections 18..............................................
Routing and strain relief of cables 21................................................
Inserting the boiler coding card 22.....................................................
Adjustment of the fixed high limit 23................................................
Adjustment of the adjustable high limit 24.....................................
Connection of the outdoor temperature sensor 25.....................
Connection of the boiler temperature sensor
and other sensors 26
................................................................................
Connection of the pumps 30.................................................................
Connection of boiler return mixing-valve or
modulating valve actuator 32
................................................................
Making space for accessory adaptors on the DIN rail
(CM2 only) 34
...............................................................................................
Connections to plug aBÖ 35..................................................................
Compiled failure alarm indicator 36.....................................................
Connection of external equipment to plug aVD 38......................
Connection of external equipment to plug aVH 39......................
Connection of external controls 40.....................................................
Connection of combustion air device 45..........................................
Connection of low water cut-off device 49....................................
Burner connection, burner control wiring 51..................................
Power supply connection, boiler control 55.....................................
Mounting the front part of the control unit 57..............................
Opening the control unit 59...................................................................
Start-up Procedure (overview) 63.........................................................................
Steps 64.........................................................................................................
5285 941 - 01

Index
5
Page
Scanning service information Overview of service levels 72...............................................................
Temperatures, boiler coding cards and scanning 73...................
Scanning operating status information 77.......................................
Scanning and resetting the ”Service” display 78.........................
Troubleshooting Troubleshooting steps 79........................................................................
Diagnosis 80.................................................................................................
Functional description Boiler temperature control 86.................................................................
Heating circuit control 87.........................................................................
DHW tank temperature control 90.......................................................
Additional information Overview 92.................................................................................................
Technical data 93.......................................................................................
System components 94...........................................................................
Coding 1 114..................................................................................................
Coding 2 116..................................................................................................
Wiring diagram 135......................................................................................
5285 941 - 01

Heating system types
6
Heating system types for modulating boilers
System type 1 – Single-boiler system with shunt pump for raising the return temperature
in conjunction with
Vitorond 200, VD2
ABoiler with Vitotronic 300
BDomestic hot water tank
CHeating circuit with mixing valve
plugs
!Outdoor temperature sensor
?M2 Supply temperature sensor,
mixing valve circuit 2
?M3 Supply temperature sensor,
mixing valve circuit 3
§Boiler temperature sensor
%DHW tank temperature sensor
aJATemperature sensor T1
aJBTemperature sensor T2
sÖ A1 Close mixing valves with
external heating circuit controls
sÖ M2 Heating circuit pump, mixing
valve circuit 2
sÖ M3 Heating circuit pump, mixing
valve circuit 3
sA DHW pump
sK DHW re-circulation pump
sL Shunt pump
fÖ Power supply connection,
120 VAC
fA Burner (1st stage)
gS M2 Mixing valve motor, mixing
valve circuit 2
gS M3 Mixing valve motor, mixing
valve circuit 3
lÖ Burner (2nd stage/modulating)
aVD Connection of external
equipment (see page 38)
aVH Connection of external
equipment (see page 39)
*1 On the Vitorond the boiler supply and return are at the rear of the boiler.
5285 941 - 01
A1 M2 M3
5
21
28
1
B
CC
2
20
52
M3
A
90 41 40
146 143
3
17A
17B
T1
T2
*1
2
20
52
M2
29 20 2 20 52 2 20 52

Heating system types
7
Heating system types for modulating boilers (continued)
Possible applications
Heating systems with manifold
arranged close to the boiler. The boiler
water flow is required to be reduced.
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the temperature sensor T2 switches
on the shunt pump. If the minimum
return temperature is not reached
despite raising the return temperature,
the flow must be reduced by at least
50% via the temperature sensor T1.
The shunt pump must be sized so that
bypassed water accounts for approx.
30%ofthetotalflowrateofthe
boiler.
Temperature sensor T1
Wiring of the temperature sensor
T1 in heating systems with heating
circuit control units which are not
connected via the LON BUS to the
boiler control unit.
Coding required: ”4C : 2” – use
plug sÖ for closing the mixing
valves of the heating circuits
connected downstream.
sÖ A1 Close mixing valves
AContactor relay, field supplied
BHeating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.
Available system accessories
Vitotrol remote control
Flue gas temperature sensor
Coding of
system type
Change required Automatic change
00: 1 If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 101)
The system type is recognized automatically
when the sensors are connected
02: 1 Set coding ”02: 2” for operation with
modulating burner
––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible) ––
4A: 0 –– Connection of the temperature sensor T1 at
plug aJA;
Coding ”4A: 1” is set automatically
4b: 0 –– Connection of the temperature sensor T2 at
plug aJB;
Coding ”4b: 1” is set automatically
5285 941 - 01

Heating system types
8
Circuit Diagram 1
Single-boiler system with Therm-Control and three-way mixing valve
in conjunction with Vitorond 200, VD2A
AHeating circuit with mixing valves
BDHW tank
Plug
!Outdoor temperature sensor
?M2 Flow temperature sensor,
mixing valve
?M3 Flow temperature sensor,
mixing valve
§Boiler water temperature
sensor
%DHW tank temperature sensor
aJATherm-Control temperature
sensor
sÖM2 Heating circuit pump, mixing
valve
sÖM3 Heating circuit pump, mixing
valve
sÖA1 Closing the mixing valves with
external heating circuit control
units
sA DHW primary pump
sK DHW circulation pump
fÖ Power supply, 120 VAC
60 Hz
Install the main isolator in
accordance with regulations
fA Burner (stage 1)
gSM2 Mixing valve motor
gSM3 Mixing valve motor
lÖ Burner
(burner stage 2 / mod.)
aVD/aVH External connections
Please refer to the control
manual Vitocontrol-S,
VD2/CT3.
5285 941 - 01

Heating system types
9
Circuit Diagram 1 (continued)
sÖ A1 Close mixing valves
AContactor relay, field supplied
BHeating circuit controls
connected downstream
Switch contact closed: signal
for ”close mixing valve”.
Wiring diagram
Wiring of the Therm-Control in heating
systems with heating circuit control units
are not connected to the boiler control
unit via the LON.
Required coding:
Change “4C” to “2” - use the plug-in
connector 20 A1 to close the
downstream mixing valve. Change “0D”
to “1” - the Therm-Control acts on the
mixing valve of the downstream heating
circuits (for Vitotronic 200 and 300,
delivered condition).
5285 941 - 01

Heating system types
10
Heating system types for modulating boilers (continued)
System type 2 – Single-boiler system with shunt pump and return valve for raising the return temperature
in conjunction with
Vitorond 200, VD2
ABoiler with Vitotronic 300
BDomestic hot water tank
CHeating circuit with mixing valve
plugs
!Outdoor temperature sensor
?M2 Supply temperature sensor,
mixing valve circuit 2
?M3 Supply temperature sensor,
mixing valve circuit 3
§Boiler temperature sensor
%DHW tank temperature sensor
aJATemperature sensor T1
aJBTemperature sensor T2
sÖ M2 Heating circuit pump, mixing
valve circuit 2
sÖ M3 Heating circuit pump, mixing
valve circuit 3
sA Circulation pump for heating
the DHW tank
sK DHW re-circulation pump
sL Shunt pump
fÖ Power supply connection,
120 VAC
fA Burner (1st stage)
gS A1 Mixing valve motor for raising
the return temperature
gS M2 Mixing valve motor, mixing
valve circuit 2
gS M3 Mixing valve motor, mixing
valve circuit 3
lÖ Burner (2nd stage/modulating)
aVD Connection of external
equipment (see page 38)
aVH Connection of external
equipment (see page 39)
*1 On the Vitorond the boiler supply and return are at the rear of the boiler.
5285 941 - 01
M2 M3
29 52 2 20 52 2 20 52
5
21
28
1
B
CC
2
20
52
M3
A
90 41 40
146 143
3
17A
17B
T1
T2
*1
2
20
52
M2
A1

Heating system types
11
Heating system types for modulating boilers (continued)
Possible applications
Heating systems with distributor
arranged close to the boiler. The boiler
water flow is required to be reduced.
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
When the return temperature falls
below the required minimum value,
the temperature sensor T2 switches
on the shunt pump. If, as a result,
the required minimum return
temperature is not reached, the
return valve is proportionally closed
via the temperature sensor T1 and
the minimum return temperature is
assured.
The shunt pump must be sized so that
bypassed water accounts for approx.
30%ofthetotalflowrateofthe
boiler.
Available system accessories
Vitotrol remote control
Flue gas temperature sensor
Coding
system type
Change required Automatic change
00: 1 If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)
The system type is recognized automatically
when the sensors are connected
02: 1 Set coding ”02: 2” for operation with
modulating burner
––
03: 0 Set coding ”03: 1” for oil-fired operation
(re-setting is not possible) ––
0C: 0 Set coding ”0C: 1” for continuous return
temperature control
––
4A: 0 –– Connection of the temperature sensor T1 at
plug aJA;
Coding ”4A: 1” is set automatically
4b: 0 –– Connection of the temperature sensor T2 at
plug aJB;
Coding ”4b: 1” is set automatically
5285 941 - 01

Heating system types
12
Heating system types for condensing boilers
System type 3 – Single-boiler system with Vitocrossal 300
ABoiler with Vitotronic 300
BDomestic hot water tank
CHeating circuit with mixing valve
DNeutralizing unit
plugs
!Outdoor temperature sensor
?M2 Supply temperature sensor,
mixing valve circuit 2
?M3 Supply temperature sensor,
mixing valve circuit 3
§Boiler temperature sensor
%DHW tank temperature sensor
sÖ A1 Heating circuit without mixing
valve (if installed)
sÖ M2 Heating circuit pump, mixing
valve circuit 2
sÖ M3 Heating circuit pump, mixing
valve circuit 3
sA Circulation pump for heating
the DHW tank
sK DHW re-circulation pump
fÖ Power supply connection,
120 VAC
fA Burner (1st stage)
gS M2 Mixing valve motor, mixing
valve circuit 2
gS M3 Mixing valve motor, mixing
valve circuit 3
lÖ Burner (2nd stage/modulating)
aVD Connection of external
equipment (see page 38)
aVH Connection of external
equipment (see page 39)
5285 941 - 01
20 2 20 52 2 20 52
A1 M2 M3
3
5
21
28
1
B
CC
2
20
52
M3
A
90 41 40
146 143
D
2
20
52
M2

Heating system types
13
Heating system types for condensing boilers (continued)
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
The Vitocrossal 300 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Viessmann modulating
burner is operated through Vitotronic
control.
The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.
Available system accessories
Vitotrol remote control
Flue gas temperature sensor
Coding
system type
Change required Automatic change
00: 1 If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)
The system type is recognized automatically
when the sensors are connected
02: 1 Set coding ”02: 2” for operation with
modulating burner
––
0d: 1 Set coding ”0d: 0” ––
5285 941 - 01

Heating system types
14
Heating system types for condensing boilers (continued)
System type 4 - Single-boiler system with Vitocrossal 300 with several heating circuits and one modulating supply
temperature heating circuit
ABoiler with Vitotronic 300
BDomestic hot water tank
CHeating circuit with mixing valve
DModulating supply temperature
heating circuit
or
EUnderfloor heating circuit
FHigh limit thermostat (max. limit)
GNeutralizing unit
plugs
!Outdoor temperature sensor
?M2 Supply temperature sensor,
mixing valve circuit 2
?M3 Supply temperature sensor,
mixing valve circuit 3
§Boiler temperature sensor
%DHW tank temperature sensor
sÖ A1 Heating circuit without mixing
valve (if installed)
sÖ M2 Heating circuit pump, mixing
valve circuit 2
sÖ M3 Heating circuit pump, mixing
valve circuit 3
sA Circulation pump for heating
the DHW tank
sK DHW re-circulation pump
fÖ Power supply connection
120 VAC
fA Burner (1st stage)
gS M2 Mixing valve motor, mixing
valve circuit 2
gS M3 Mixing valve motor, mixing
valve circuit 3
lÖ Burner (2nd stage/modulating)
aVD Connection of external
equipment (see page 38)
aVH Connection of external
equipment (see page 39)
5285 941 - 01
20 2 20 52 2 20 52
A1 M2 M3
3
5
21
28
1
B
CD
2
20
52
M3
A
90 41 40
146 143
G
or
E
2
M3
20
52
2
20
52
M2 F

Heating system types
15
Heating system types for condensing boilers (continued)
Possible applications
For heating circuits with different
temperatures.
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
The Vitocrossal 300 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Two-stage or modulating
burners can be controlled.
The Vitocrossal 300 has two return
connections. The heating circuits with
the higher return temperature are
connected to the return connection
at the top, those with the lower
temperatures to the return connection
at the bottom. Please note: At least
15% of the take-off from the rated
output must be connected to the
return connection at the bottom.
The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.
Pumps in the underfloor heating
circuit
sÖ Heating circuit control unit
APrimary pump of underfloor
heating circuit
BHigh limit thermostat (max. limit)
CSecondary pump of underfloor
heating circuit (after system
separation)
Coding
system type
Change required Automatic change
00: 1 If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)
The system type is recognized automatically
when the sensors are connected
02: 1 Set coding ”02: 2” for operation with
modulating burner
––
0d: 1 Set coding ”0d: 0” ––
5285 941 - 01
20
A B C
20
LN

Heating system types
16
Heating system types for condensing boilers
System type 5 – Single-boiler system with Vitocrossal 200
ABoiler with Vitotronic 300
BDomestic hot water tank
CHeating circuit with mixing valve
DNeutralizing unit
plugs
!Outdoor temperature sensor
?M2 Supply temperature sensor,
mixing valve circuit 2
?M3 Supply temperature sensor,
mixing valve circuit 3
§Boiler temperature sensor
%DHW tank temperature sensor
sÖ A1 Heating circuit without mixing
valve (if installed)
sÖ M2 Heating circuit pump, mixing
valve circuit 2
sÖ M3 Heating circuit pump, mixing
valve circuit 3
sA Circulation pump for heating
the DHW tank
sK DHW re-circulation pump
fÖ Power supply connection,
120 VAC
fA Burner (1st stage)
gS M2 Mixing valve motor, mixing
valve circuit 2
gS M3 Mixing valve motor, mixing
valve circuit 3
lÖ Burner (2nd stage/modulating)
aVD Connection of external
equipment (see page 38)
aVH Connection of external
equipment (see page 39)
5285 941 - 01

Heating system types
17
Heating system types for condensing boilers (continued)
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
The Vitocrossal 200 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Viessmann modulating
burner is operated through Vitotronic
control.
The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.
Available system accessories
Vitotrol remote control
Coding
system type
Change required Automatic change
00: 1 If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)
The system type is recognized automatically
when the sensors are connected
02: 1 Set coding ”02: 2” for operation with
modulating burner
––
0d: 1 Set coding ”0d: 0” ––
5285 941 - 01

Installation
18
Overview of electrical connections
Mixing valve extension circuit board
?M2/M3 Supply temperature sensor
sÖ M2/M3 Heating circuit pump
gS M2/M3 Mixing valve motor
Low-voltage motherboard
!Outdoor temperature sensor
(ATS)
§Boiler temperature sensor (BTS)
%DHW tank temperature sensor
(STS)
aG Flue gas temperature sensor
(AGS) (accessory)
aJATherm-Control temperature
sensor
or
return temperature sensor T1
(RLS) (accessory)
aJBReturn temperature sensor T2
(RLS) (accessory)
aVD Connection of external
equipment
aVG KM BUS participant, e.g.
Vitotrol remote control
(accessory)
aVH Connection of external
equipment
Line voltage motherboard
sÖ A1 Heating circuit pump or
control output
sA Circulation pump for heating
the DHW tank (accessory)
sK DHW re-circulation pump
(provided by customer)
sL Shunt pump
fÖ Power supply connection
fA Burner (1st stage)
gÖ Central fault indicator
gSA1 Continuous return
temperature control
or
3-way mixing valve for DHW
tank loading system
lÖ Burner (2nd stage/modulating)
aBÖ Connection of external
equipment, e.g. additional
safety equipment
aBA Safety circuit, potential free
aBH Power supply connection for
accessories
5285 941 - 01
145
145
1
17
17
15
143
146
150
28
21
52
20
29
50
40
156
156
A
B
52
52
20
20
2
2
M3
M2
M3
M2
M3
M2
A1
A1
5
90
41
151
3/2

Installation
19
Overview of electrical connections(for VD2/VD2A/CT3 only)
5285 941 - 01

Installation
20
Overview of electrical connections (for CM2 only)
5285 941 - 01