Viessmann VITOTRONIC 300 Quick guide

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5693 973 - 03 07/2014
for use by heating contractor
VITOTRONIC 300, GW5B
VITOTRONIC 300-K, MW1B
Installation and Service
Instructions
Vitotronic 300-K, MW1B
Vitotronic 300, GW5B
Vitotronic 300, Type GW5B
Digital boiler control unit
Vitotronic 300-K, Type MW1B
Weather-compensated digital cascade control unit
IMPORTANT
Certified as a component
part for Viessmann boilers

5693 973 - 03
Vitotronic 300, GW5B and MW1B Installation and Service
General
Safety, Installation and Warranty Requirements
Please ensure that these instructions are read and understood before commencing installation. Failure to comply with
the instructions listed below and details printed in this manual can cause product/property damage, severe personal
injury, and/or loss of life. Ensure all requirements below are understood and fulfilled (including detailed information
found in manual subsections).
WARNING
Installers must follow local regulations with respect to
installation of carbon monoxide detectors. Follow the
Viessmann maintenance schedule of the boiler contained
in this manual.
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 Safety Requirements”.
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”.
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, shutdown procedure, and
the need for professional service annually before the
heating season begin.
Warranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
Operating and Service Documentation
It is recommended that all product documentation such
as parts lists, operating and service instructions be
handed over to the system user for storage.
Documentation is to be stored near boiler in a readily
accessible location for reference by service personnel.
Product Information
Vitotronic 300, Type GW5B
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
2

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3
Table of Contents
Vitotronic 300, GW5B and MW1B Installation and Service
General
Safety
Preparing for Installation
Installation, Vitotronic 300, GW5B
Installation, Vitotronic 300-K
Safety, Installation and Warranty Requirements..............2
Product documentation......................................2
Warranty..........................................................2
Licensed professional heating contractor..............2
Advice to owner................................................2
Operating and Service Documentation..................2
Product Information....................................................2
About these Instructions.............................................6
For your Safety..........................................................7
Operation.........................................................7
Flue gas smell...................................................7
Working on the equipment..................................7
Maintenance and cleaning .................................7
Technical Data Manual.......................................7
If you smell gas................................................7
In emergencies..................................................7
Installation of additional components...................7
Boiler room conditions.......................................7
Safety Terminology.....................................................7
Designation in the System Example...............................8
Overview of System Example.......................................8
System Example.........................................................9
Overview of Electrical Connections.............................15
120V External Connection Overview....………………..…17
Inserting Cables and Applying Strain Relief..................18
Inserting the Boiler Coding Card.................................18
Inserting the LON Communication Module...................19
Connecting Sensors..................................................19
120V External Connection…………………………..………19
Connecting Actuators................................................21
Connection the Central Fault Massage Facility..............22
Connection of low Water Cut-off Device…………………22
Connections to Terminal 150………………………….……23
Connections to Terminal 151………………………….……23
Blocking Boiler Externally / Adding to the Boiler Sequence...24
Connecting a Burner.................................................25
Preparing Boilers for Cascade Mode…………………....…25
Overview of Electrical Connections.............................26
Mounting the Control Unit.........................................28
Inserting Cables/Leads and Applying Strain Relief………29
Connecting Pumps....................................................30
Connecting Sensors..................................................31
120V External Connection……………………………..……32
Connecting Actuators...............................................33
Connection Central Fault Massage Facility...................34
External Demand Via Switching Contact......................34
External Demand via 0-10V Input...............................35
External Blocking via Switching Contact......................35
External “Mixing Valve Closed” / “Mixing Valve Open”......36
External Heating Program Changeover.........................36
Making the LON Connection.......................................37

Table of Contents
4
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Vitotronic 300, GW5B and MW1B Installation and Service
Power Supply
Opening and Closing the Control Units
Commissioning
Preparing for Installation
Installation Sequences
Service Scans, Vitotronic 300, GW5B
Service Scans, Vitotronic 300-K
Troubleshooting, Vitotronic 300, GW5B
Troubleshooting, Vitotronic 300-K
Function Description
Power Supply...........................................................38
Fitting the Control Unit Front......................................39
Opening the Control Unit...........................................39
Testing the High Limit Safety Cut-out..........................40
Changing the Language on the Vitotronic 300-K...........40
Setting the Date and Time the Vitotronic 300-K...........40
Matching the Coding Addresses to the System Version....41
Selecting the Boiler Sequence at the Vitotronic 300-K...42
Connecting the Control Unit to the LON......................43
Checking Actuators and Sensors at the
Vitotronic 300 GW5B...............................................46
Checking Actuators and Sensors at the
Vitotronic 300-K......................................................47
Adjusting Heating Curves...........................................48
Calling up Service Menu............................................50
Exiting Service Menu................................................50
Calling up Service Menu............................................51
Scanning Operating Data...........................................51
Brief Scan...............................................................52
Scanning and Resetting Service Display.......................52
Fault Codes.............................................................53
Fault Display............................................................55
Fault Codes..............................................................56
Boiler Temperature Control of the
Vitotronic 300 GW5B...............................................60
Cascade Control of the Vitotronic 300-K.....................62
Heating Circuit Control Unit of the Vitotronic 300-.......65
DHW Tank Temperature Control of the
Vitotronic 300-K.......................................................69

Table of Contents
5
Page
5693 973 - 03
Vitotronic 300, GW5B and MW1B Installation and Service
Code 1, Vitotronic 300, GW5B
Code 2, Vitotronic 300, GW5B
Code 1, Vitotronic 300-K
Code 2, Vitotronic 300-K
Wiring, Vitotronic 300, GW5B
Wiring, Vitotronic 300-K
Components
Parts Lists
Specification
Calling up Coding Level 1..........................................71
Group 1 “General”....................................................71
Group 2 “ Boiler”......................................................72
Calling up Coding Level 2..........................................73
Group 1 “General”....................................................74
Group 2 “ Boiler”......................................................78
Calling up Coding Level 1..........................................79
“General” Group.......................................................80
“Cascade” Group.....................................................81
“DHW”Group………….………………………………….……81
“Solar” Group..........................................................82
“Heating Circuit 1”, “Heating Circuit 2”,
“Heating Circuit 3” Group..........................................83
Calling up Coding Level 2..........................................86
“General” Group.......................................................87
“Cascade” Group.....................................................92
“DHW” Group..........................................................93
“Solar” Group...........................................................95
“Heating Circuit 1”, “Heating Circuit 2”,
“Heating Circuit 3” Group..........................................98
Connection and Wiring Diagram................................103
Connection and Wiring Diagram................................106
Sensors.................................................................110
Boiler Coding Card..................................................111
Mixing Valve Motor Kit............................................111
Extension EA1 Accessory (optional).........................112
Parts List Vitotronic 300, GW5B..............................113
Parts List Vitotronic 300-K......................................114
Specification Vitotronic 300, GW5B.........................115
Specification Vitotronic 300-K.................................115

Vitotronic 300, GW5B & MW1B Installation and Service
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6
Safety
About these Instructions
Take note of all symbols and notations intended to draw attention to potential hazards or important product
information. These include “WARNING”, “CAUTION”, and “IMPORTANT”. See below.

IMPORTANT
Warnings draw your attention to the presence of
potential hazards or important product information.
Cautions draw your attention to the presence of
potential hazards or important product information.
Helpful hints for installation, operation or maintenance
which pertain to the product.
This symbol indicates that additional, pertinent
information is to be found.
This symbol indicates that other instructions must
be referenced.
WARNING
Indicates an imminently hazardous situation which,
if not avoided, could result in loss of life, serious injury
or substantial product/property damage.
CAUTION
Indicates an imminently hazardous situation which,
if not avoided, may result in minor injury or product/
property damage.

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5693 973 - 03
Vitotronic 300, GW5B & MW1B Installation and Service
If you smell gas
HDon’t smoke! Don’t use naked flames or cause sparks
(e.g. by switching lights or electrical appliances on
and off)
HOpen windows and doors
HClose the gas shut-off valve
HInform your heating engineers/service contractors from
outside the building
HObserve the safety regulations of your gas supply
company (see gas meter) and those of your heating
engineers (see start-up or instruction report).
In emergencies
HImmediately switch off the power supply, e.g. at the
separate fuse or power supply disconnect switch
(unless there is a smell of gas).
HClose the shut-off valves in the oil pipes or close the
gas shut-off valve, whichever applicable.
HUse suitable extinguishers in the event of fire.
Installation of additional components
The installation of additional components which have not
been tested together with the boiler can adversely affect
the function and performance of the boiler.
Our warranty does not cover and weaccept no liability
for damage attributable to the installation of such
components.
Boiler room conditions
HDo not use a room in which the air is polluted by
halogenated hydro-carbons (e.g. as contained in
aerosols, paints, solvents and cleaning agents)
HDo not use a room subject to high levels of dust
HDo not use a room subject to permanently high humidity
HThe room should be frost-protected
HMax. ambient temperature 95° F (35° C).
HProvide good ventilation and do not close or obstruct
vents (if installed).
This symbol indicates a reference to other instructions
which must be observed.
Safety
CAUTION
Follow these safety instructions closely to avoid the risk
of injury and damage to property.
For your Safety
HOperation
Before operating the boiler, make sure you fully
understand its method of operation. Your heating
contractor should always perform the initial start-up
and explain the system. Any warranty is null and void
if these instructions are not followed.
HFlue gas smell
- Deactivate heating equipment.
- Open windows and doors.
- Inform your heating contractor.
HWorking on the equipment
All personnel working on the equipment or the heating
system must have the proper qualifications and hold
all necessary licenses. Ensure main power to
equipment, heating system, and all external controls
has been deactivated. Close main gas supply valve.
Take precautions in all instances to avoid accidental
activation of power during service work.
HDangerous conditions
- Deactivate main power immediately.
- Close gas supply valve.
HMaintenance and cleaning
Regular inspection and service by a qualified heating
contractor is important to the performance of the boiler.
Neglected maintenance impacts on warranty; regular
inspection ensures clean, environmentally friendly and
efficient operation. We recommend a maintenance
contract with a qualified heating contractor.
HTechnical Data Manual
- Installation Instruction and Service Instructions
- Operating Instructions and User’s Information Manual
Additional applicable literature:
- Accessory manuals
Safety Terminology
Take note of all symbols and notations intended to draw attention to potential hazards or important product
information. These include ”WARNING” and ”CAUTION”. See below.
WARNING
Indicates an imminently hazardous situation which,
if not avoided, could result in substantial product /
property damage, serious injury or loss of life.
CAUTION
Indicates an imminently hazardous situation which,
if not avoided, may result in minor injury or product /
property damage.

8
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Vitotronic 300, GW5B and MW1B Installation and Service
Preparing for Installation
Designations in the System Example
Overview of System Example
HThis system example is merely a generic layout and
must therefore be checked on site for completeness
and function.
HConnect three-phase consumers via additional
contactors.
HWith the Vitotronic 300-K, the communication module
is integrated.
Boiler Characteristics Page
Vitocrossal, 200 CM2 Multi-boiler installation 9

9
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Vitotronic 300, GW5B & MW1B Installation and Service Preparing for Installation
System Example
Multi boiler system: Vitocrossal 200 CM2
Hydraulic installation layout
Note: This layout is a basic example without shut-off
devices or safety equipment. This does not replace
the need for local engineering.

Vitotronic 300, GW5B & MW1B Installation and Service
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Preparing for Installation
System Example (continued)
Equipment required
Pos. Description
1Boiler I (cascade mode)
2Neutralizing system
3Boiler water temperature sensor KTS
5Supply temperature sensor, common heating supply VTS as
contact temperature sensor (standard delivery for Vitotronic 300-K)
or
immersion temperature sensor
6Outside temperature sensor ATS
7Vitotronic 300-K
8Vitotronic 300, GW5B
9Boiler II (cascade mode)
qP Neutralizing system
qQ Boiler water temperature sensor KTS
qE Vitotronic 300, GW5B
qR DHW tank
qT DHW tank temperature sensor STS
qZ Circulation pump for DHW tank heating UPSB
qU DHW circulation pump ZP
qI Heating circuit 2
wP Heating circuit pump M2
Extension kit for one heating circuit with mixing valve:
qO Supply temperature sensor M2 as contact temperature sensor
and
wQ Mixing valve motor M2
or
qO Supply temperature sensor M2 as
contact temperature sensor
or
immersion temperature sensor
and
wQ Mixing valve motor for flanged mixing valve M2
wW Heating circuit 3
wR Heating circuit pump M3
Extension kit for one heating circuit with mixing valve:
wE Supply temperature sensor M3 as contact temperature sensor
and
wT Mixing valve motor M3
wE
or
Supply temperature sensor M3 as
contact temperature sensor
or
immersion temperature sensor
and
wT Mixing valve motor for flanged mixing valve M3
wZ Heating circuit 1 at the Vitotronic 200-H
wI Heating circuit pump M1
Extension kit for one heating circuit with mixing valve:
wU Supply temperature sensor M1 as contact temperature sensor
and
wO Mixing valve motor M1
or

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5693 973 - 03
Vitotronic 300, GW5B & MW1B Installation and Service Preparing for Installation
System Example (continued)
Equipment required
Pos. Description
wU Supply temperature sensor M1 as
contact temperature sensor
or
immersion temperature sensor
and
wO Mixing valve motor for flanged mixing valve M1
eP Vitotronic 200-H
and
LON communication module (accessory)
and
LON connecting cable (accessory)
eQ Outside temperature sensor ATS
Boiler accessories
eR Plug-in adaptor for external safety equipment
eT Minimum pressure limiter SDB
eZ Maximum pressure limiter SDB
eU Low water cutoff
eI Central fault message system
External hook-ups
zR - External changeover of stepped/modulating burners
zI - External boiler blocking
zO - Start boiler externally as the last one in the boiler sequence
System accessories
eE Vitotrol 200 A or Vitotrol 300 A
eI Central fault message system
rP ON/OFF switch
rI Vitocom 100 LAN1
tP KM BUS distributor, for several KM BUS participants
zP Extension EA1
zQ 1 switching output (floating changeover contact):
- Switching a accessories pump to a substation
- Signalling reduced mode for a heating circuit
zW 1 analogue input (0–10V):
- Specifying the set system supply temperature
zE 3 digital inputs:
External heating program changeover, separately adjustable for heating circuits 1 to 3
External demand
External blocking with fault message
Fault message input
Short term operation of DHW circulation pump
External hook-ups
zT - External blocking/mixing valve closed
zZ - External demand
zU - External heating program changeover/mixing valve open
uP LON communication module (standard delivery Vitotronic 300-K) for communication with the following
components:
Vitotronic boiler and heating circuit control units

Vitotronic 300, GW5B & MW1B Installation and Service
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12
Preparing for Installation
System Example (continued)
Electrical installation wiring

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Vitotronic 300, GW5B & MW1B Installation and Service Preparing for Installation
System Example (continued)

Vitotronic 300, GW5B & MW1B Installation and Service
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14
System Example (continued)
Preparing for Installation
Code required at every Vitotronic 300, GW5B
Group Function
01:2 2 “Boiler” Multi boiler system with cascade control via LON
Boiler number at the Vitotronic:
07:2 2 “Boiler” Boiler 2
07:3 2 “Boiler” Boiler 3
07:4 2 “Boiler” Boiler 4
LON participant number at the Vitotronic:
77:2 1 “General” Vitotronic 300-K with two Vitotronic 300, GW5B
77:3 1 “General” Boiler 3
77:4 1 “General” Boiler 4
Code required at the Vitotronic 300-K
Group Function
00:3,
00:4,
00:7,
00:8
System scheme without system circuit (heating circuit A1)
35:1 “Cascade” Vitotronic 300-K with one Vitotronic 300, GW5B
35:2 “Cascade” Vitotronic 300-K with two Vitotronic 300, GW5B
35:3 “Cascade” Vitotronic 300-K with three Vitotronic 300, GW5B
35:4 “Cascade” Vitotronic 300-K with four Vitotronic 300, GW5B

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Vitotronic 300, GW5B & MW1B Installation and Service
Overview of Electrical Connections
Installation, Vitotronic 300, GW5B
Note: When connecting plugs aVDand aVH, bundle the
individual cores of the cables close to the terminals.
This prevents the cores from shifting into the
neighboring voltage area.
Main PCB 120V~
sÖA1 Switching output pump
sL Boiler circuit pump
fÖ Power supply
fA Burner (call for heat)
gÖ Central fault message
gSA1 Isolation valve
aBÖExternal connections, e.g. supplementary safety
equipment
aBASafety chain, floating
aBHPower supply connection for accessories
Main PCB low voltage
aJA Return temperature sensor T1
(optional accessory, not used)
aJB Return temperature sensor T2
(optional accessory, not used)
aVDExternal hook-up
aVGKM BUS participant (accessory)
aVHExternal hook-up
Prior to making any connections ensure that the
control control and junction box have been installed as
per the boiler Installation Instructions.

Vitotronic 300, GW5B & MW1B Installation and Service
5693 973 - 03
16
Overview of Electrical Connections (continued)
Installation, Vitotronic 300, GW5B

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5693 973 - 03
Vitotronic 300, GW5B & MW1B Installation and Service Installation, Vitotronic 300, GW5B
120V External Connection Overview
Pumps 120V
Rated current: 2A~
* Maximum output 6FLA shared between all
120V outputs.
Legend
APumps
BTo the control unit
Available pump connections
sÖM1/A1 Switching contact
sL Boiler pump

Vitotronic 300, GW5B & MW1B Installation and Service
5693 973 - 03
18
Inserting Cables and Applying Strain Relief
Legend
ACables with moulded strain relief
BOn-site cables; strip up to 4 in. (100 mm) insulation
Installation, Vitotronic 300, GW5B
HControl unit fitted on the boiler:
Route cables from below through the front panel of the
boiler into the wiring chamber of the control unit.
HControl unit fitted to the side of the boiler:
Route cables from below out of the cable channel into
the control unit.
Inserting the Boiler Coding Card
Only use the boiler coding card supplied with the boiler
(see table in chapter “Components”).
Insert the boiler coding card into slot “X7”, through the
recess in the cover.
Boiler Coding card Part no.
Vitocrossal 200, CM2 1042 7841113

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5693 973 - 03
Vitotronic 300, GW5B & MW1B Installation and Service
Connecting Sensors
Legend
Main PCB low voltage
aJA Return temperature sensor T1 (optional accessory)
aJB Return temperature sensor T2 (optional accessory)
Installation, Vitotronic 300, GW5B
120V pumps with an amperage draw of <2FLA
ADin rail
BPump
120V External Connection
Inserting the LON Communication Module
Making the LON connection, see page 37.

Vitotronic 300, GW5B & MW1B Installation and Service
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20
120V External Connection (continued)
120V pumps with an amperage draw of >2FLA
208/460/575V 3 phase pumps
240V pumps
Contactor specification 120VAC 1A
ADin rail
BContactor/relay (field supplied)
CPump
DPower supply w/disconnect and protection
Contactor specification 120VAC 1A
ADin rail
BContactor/relay (field supplied)
CPump
DPower supply w/disconnect and protection
Contactor specification 120VAC 1A
ADin rail
BContactor/relay (field supplied)
CPump
DPower supply w/disconnect and protection
Installation, Vitotronic 300, GW5B