Viessmann VITOLIGNO 300-C Quick guide

for use by heating contractor
5790 980 - 04 10/2018
Installation and Service
Instructions
VITOLIGNO 300-C
Pellet boiler, with Ecotronic weather-compensated,
digital boiler and heating circuit control unit
Heating input: 44 MBH to 193 MBH
13 kW to 57 kW
Please file in Service Binder
Product may not be exactly as shown
H

Vitoligno 300-C Installation/Service
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Safety Instructions
Safety
Safety, Installation and Warranty Requirements
WARNING
Installers must follow local regulations with respect
to installation of carbon monoxide detectors. Follow
manufacturer’s maintenance schedule of the boiler
contained in the ”Service and Maintenance Instructions”.
Please ensure that these instructions are read and understood before commencing installation and service. 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).
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”.
Warranty
Information contained in this and
related product documentation must
be read and followed. Failure to do
so renders the warranty null and void.
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”.
Contaminated air
Air contaminated by chemicals can cause by-products
in the combustion process, which are poisonous to
inhabitants and destructive to Viessmann equipment.
For a listing of chemicals which
cannot be stored in or near the
boiler room, please see subsection
entitled “Mechanical Room”.
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. Refer to the Service
and Maintenance Instructions for details.
Carbon monoxide
Improper installation, adjustment, service and/or
maintenance can cause flue products to flow into
living space. Flue products contain poisonous carbon
monoxide gas.
For information pertaining to the proper
installation, adjustment, service and
maintenance of this equipment to avoid
formation of carbon monoxide, refer
to the “Safety” section.
Fresh air
This equipment requires fresh air for
safe operation and must be installed
ensuring provisions for adequate
combustion and ventilation air exist.
For information pertaining to the
fresh air requirements of this product,
refer to the“Combustion Air Supply”
section.
Equipment venting
Never operate boiler without an installed venting
system. An improper venting system can cause
carbon monoxide poisoning.
For information pertaining to
venting and chimney requirements,
refer to the “Safety” section. All
products of combustion must be
safely vented to the outdoors.

3
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Vitoligno 300-C Installation/Service
Safety Instructions
Safety
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.
CAUTION
Cautions draw your attention to the presence of potential
hazards or important product information.
WARNING
Warnings draw your attention to the presence of potential
hazards or important product information.

IMPORTANT
Indicates an imminently hazardous situation which,
if not avoided, could result in death, serious injury or
substantial product/property damage.
Indicates an imminently hazardous situation which,
if not avoided, may result in minor injury or product /
property damage.
Helpful hints for installation, operation or maintenance
which pertain to the product.
This symbol indicates to note additional information
This symbol indicates that other instructions must be
referenced.
Note: Viessmann Manufacturing Company Inc. reserves
the right to make product changes or updates
without notice and will not be held liable for
typographical errors or omissions in the product
literature.

Page
Table of ContentsTable of Contents
4
Page
Vitoligno 300-C Installation/Service
Safety, Installation and Warranty Requirements..............2
Safety Instructions .....................................................3
Important Regulatory and Installation Requirements ........6
Product Information....................................................7
Applicability...............................................................8
Intended Use .............................................................8
Mechanical Room .......................................................9
Wood Fuel Requirements...........................................10
Principles of Pellet Combustion ..................................10
Pellet Quality Characteristics .....................................11
Carbon Monoxide .....................................................11
Installation Examples ................................................12
System Layout 1......................................................14
System Layout 2......................................................20
System Layout 3......................................................24
Clearances ..............................................................28
Dimensions..............................................................29
Alignment of the Flexible Screw Conveyor
to the Pellet Store ....................................................30
Handling, Transport and Siting ...................................31
Fitting the Connection Unit to the Boiler......................32
Pellet Supply via Vacuum System...............................33
Fitting the Base Plate for the Ash Box.........................35
Fitting the Ash Box...................................................35
Vacuum System Rail Assembly ..................................36
Flexible Screw Conveyor Drive Assembly ....................36
Electrical Connections...............................................41
Power Failure Provision .............................................51
Vacuum System Final Assembly.................................52
Flexible Screw Conveyor Final Assembly .....................54
Connections on the Flue Gas Side ..............................55
Combustion Air Supply .............................................57
Connections on the Heating Water Side ......................58
Filling the Heating System .........................................59
Boiler with Low Water Cut-off ...................................58
Checking all Connections on the Heating Water Side
for Leaks.................................................................61
Switching on the Power and Starting the
Commissioning Sequence ..........................................61
Setting the Language................................................61
Loading the Standard Setting.....................................61
Setting the Date.......................................................62
Setting the Time ......................................................62
Configuring the Supply System / Charging Scheme.......62
Control Unit Controls and Display Elements .................64
Selecting the Pellet Store Sensor................................64
Setting the Number of Buffer Tank Temperature Sensors..64
Selecting the type of Heating Water Buffer Tank ..........64
Setting an Additional Boiler........................................64
Selecting the Connection for Heating Circuits 1 to 4.....65
Selecting the DHW Connection ..................................65
Selecting DHW Recirculation......................................65
Selecting the Solar Connection...................................65
Selecting the Solar Type ...........................................66
Changing the Heating Circuit Designations...................66
Diagnosis ................................................................66
Safety
General Information
Boiler Connections
Installation
Commissioning, Inspection and
Maintenance
5790 980 - 04

Table of Contents
5
Page
5790 980 - 04
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Vitoligno 300-C Installation/Service
Checking Outputs (actuators) and Sensors ..................67
Calibrating the O2Probe............................................68
Filling the Vacuum Module ........................................68
Ending Commissioning ..............................................68
Displaying the Menu Structure ...................................68
Setting the Fuel Supply Times (with vacuum system)....68
Matching the Control Unit to the Heating System .........68
Setting the Heating Curves........................................69
Emissions Test after Commissioning ...........................71
Shutting Down the System........................................71
Emptying the Ash Box ..............................................71
Overview of Maintenance and Clean Work in the Boiler ..72
Cleaning the Combustion Chamber .............................73
Cleaning Secondary Heating Surfaces .........................74
Cleaning the Flue Pipe...............................................74
Removing the Flue Ash from the Chimney ...................74
Cleaning the Flue Gas Fan, Lambda Probe and
Flue Gas Temperature Sensor ....................................75
Cleaning the Ash Chamber and Ash Removal Parts.......75
Cleaning the Intake Grille and Pellet Sensor
in the Pellet Hopper ..................................................76
Lubricating Drive Chains and Drive Unit Bearings..........76
Checking all Installed Position Switches ......................76
Checking the Expansion Vessel and System Pressure....76
Emissions Test after Maintenance ..............................77
Instructing the System User.......................................77
Coding 1 .................................................................78
Coding 2 .................................................................90
Service Functions.....................................................95
Calling up Operating Conditions and Sensors ...............95
Fault Display............................................................96
High Limit Safety Cut-out ........................................102
Sensors ................................................................103
Lambda Probe........................................................104
Replacing the Ignition Element .................................104
Parts List...............................................................105
Display and Operating Elements ...............................127
Control Functions ...................................................128
Vacuum Supply Systems.........................................131
Pellet Combustion Sequence Chart ...........................131
PCB Positions ........................................................132
Technical Data....................................................... 133
Maintenance Schedule ............................................134
Commissioning, Inspection and
Maintenance (continued)
Coding
Service Checks
Troubleshooting
Service
Parts
Function Description
Connection and Wiring Diagram
Specifications
Inspection and Maintenance

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Important Regulatory and Installation Requirements
Take note of all symbols and notations intended to draw attention to potential hazards or important
product information. These include ”WARNING”, ”CAUTION”, and ”IMPORTANT”.
Codes
The installation of this unit shall be in accordance with
local codes. In the absence of local codes, use:
CSA B365 (latest edition) Installation Code for Solid-Fuel
Burning Appliances and Equipment, NFPA-211 (latest
edition) Standard for Chimneys, Fireplaces, Vents and
Solid Fuel Burning Appliances.
All electrical wiring is to be done in accordance with the
latest edition of CSA C22.1 Part 1 and/or local codes. In
the U.S. use the National Electrical Code ANSI/NFPA 70
where required by the authority having jurisdiction.
Mechanical room
Ensure the mechanical room complies with the
requirements listed in this manual. See section entitled
Mechanical Room.
Working on the equipment
The installation, adjustment, service, and maintenance
of this boiler must be done by a licensed professional
heating contractor who is qualified and experienced in
the installation, service, and maintenance of hot water
boilers. There are no user serviceable parts on the boiler,
or control.
Ensure main power supply to equipment, the heating
system, and all external controls have been deactivated.
Take precautions to avoid accidental activation of power
during service work.
Technical literature
Literature applicable to all aspects of the Vitoligno 300-C
wood-fired boiler:
- Installation and Service Instructions
- Operating Instructions
- Wiring Diagram
Please carefully read this manual prior to attempting
installation. Any warranty is null and void if these
instructions are not followed.
Failure to follow these instructions could result in
property damage, injury or loss of life. Contact
your local building and/or fire officials about installations,
restrictions and inspection requirements.
For information regarding other Viessmann
System Technology componentry, please reference
documentation of the respective product.
We offer frequent installation and service seminars
to familiarize our partners with our products. Please
inquire.
The completeness and functionality of field supplied
electrical controls and components must be verified
by the heating contractor. These include low-water
cut-offs, flow switches (if used), staging controls,
pumps, motorized valves, air vents, thermostats, etc.
Save and leave all literature at the installation site and
advise the system operator/ultimate owner where the
literature can be found. Contact Viessmann for
additional copies.
This product comes with several safety instruction
labels attached.
Do not remove!
Contact Viessmann immediately if replacement labels
are required.
General Information

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Vitoligno 300-C Installation/Service General Information
Product Information
Viessmann solid-fuel boiler may only be installed and
serviced by trained personnel.
Wood pellet fired hot water boiler for operation primarily
with modulating boiler water temperatures in closed loop
forced circulation hot water heating systems.
WARNING
Exposing the boiler to pressures and temperatures in
excess of those listed will result in damages and will
render the warranty null and void.
Maximum allowable working pressure (water)............45 psi
Maximum water temperature…................230°F (110°C)
Maximum boiler temperature…...............…203°F (95°C)
This boiler does not require a flow switch.
Codes and standards
CSA B366.1-M91
Solid Fuel Fired Central Heating Appliances
CSA C.22.2 NO. 3-M1988 (latest edition)
Electrical Features of Fuel Burning Equipment
UL2523
Solid Fuel-Fired Hydronic Heating Appliances, Water
Heaters and Boilers
CSA B365 (latest edition)
Installation Code for Solid Fuel Burning Appliances
and Equipment
ASME section IV boilers and pressure vessels
Modulation of 1:3 leads to low consumption and clean
combustion under partial load conditions. A ceramic
ignition unit consumes little power, whilst innovative
combustion technology featuring dual combustion
control with lambda probe and flue gas temperature
sensor keeps dust values low.
The Vitoligno 300-C offers versatile and flexible fuel
supply system options for almost any application.
Pellets are supplied to the boiler either via a flexible
screw conveyor or a vacuum system. Thanks to its
compact design, it is suitable for installation in rooms
with low ceiling heights. Versions with pellet supply
via a vacuum system are supplied with a pellet hopper
with integral suction turbine and capacity for one-day
operation. The wood pellet boiler is convenient to use
and is partially automated. The automated features
include ignition, heat exchanger cleaning, the self-
cleaning rotary finned grate and fully automatic removal
of ash. The mobile ash box only needs emptying once
or twice a year. Due to the sealed ash box, ash removal
is also clean and stress-free.
Operating the boiler is easy with the weather-
compensated digital Ecotronic control unit. The integral
Ecotronic controls up to four heating circuits with
mixing valve. The Ecotronic controls boilers with pellet
supply, heating circuits and the tank temperature.
The clear display, with graphic capability and multiple
line plain text user prompts, provides intuitive operation
and easy adjustment of all relevant parameters.
In combination with a solar thermal system, current
solar data is also shown on the display.
The Vitoligno 300-C is a fully automatic wood pellet
boiler. The boiler has an efficiency of up to 85% when
converting pellets into heat.
The wood pellet boiler offers a wide spectrum of
applications – from low energy houses to buildings
with a higher heat demand.
The Vitotrol 350-C (accessory) control unit extension
enables the wood pellet boiler to be operated from
the living space as well. With the 5” (125 mm) color
touchscreen display in 16:9 format, operation couldn’t
be easier. The Vitotrol 350-C enables remote control
of the boiler with all relevant adjustment options and
display of all relevant information about the boiler and
the heating water buffer tank. Optionally, the Vitotrol
350-C can be used not only as a remote controller but
also as a cascade controller. Up to four boilers can
be connected in a cascade. Additionally, one oil/gas
boiler can be enabled via the master boiler. The most
important control circuits of the cascade system can
be displayed and operated.
The heat-up condition of the buffer tank is displayed.

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General Information
Applicability
When ordering replacement parts, provide either the
16-digit boiler serial number (on the bar code label) or the
12-digit ASME/NB serial number correlate to each other.
Providing either serial number is sufficient.
Model No. Serial No.
300-C, 32 7673002 jjjjjjjjj
Model No. Serial No.
300-C, 48 7673003 jjjjjjjjj
CAUTION
The boiler serial number must be provided when ordering
replacement parts. Some replacement parts may not
reverse compatible with previous versions.
IMPORTANT
Legend
AIntegral suction turbine (version with vacuum system)
BPellet hopper (version with vacuum system only)
CVariable speed flue gas fan for modulating operation
DAutomatic heat exchanger cleaning
EEcotronic control unit with user prompts
FSelf-cleaning rotary finned grate made from stainless
steel
GCombustion chamber made from high temperature-
resistant ceramics
HRotary lock valve for 100% burn-back protection
KAutomatic ash removal with mobile ash box
Intended Use
The appliance is only intended to be installed and operated
in sealed unvented heating systems that comply with local
codes (in absence of local codes use CSA B365 (latest
edition) “Installation Code for Solid Burning Appliances and
Equipment”, in Canada NFPA-211 (latest edition),
‘standard for chimneys, fireplaces, vents, and solid fuel
burning appliances’ in the USA, with attention paid to the
associated installation, service and operating instructions.
It is only designed for the heating of heating water that is
of potable water quality. Intended use presupposes that a
fixed installation in conjunction with permissible, system-
specific components has been carried out.
Commercial or industrial usage for a purpose other
than heating the building or DHW shall be deemed
inappropriate.
Any usage beyond this must be approved by the
manufacturer in each individual case.
Incorrect usage or operation of the appliance (e.g. the
appliance being operated for longer periods when open)
is prohibited and will result in an exclusion of liability.
Incorrect usage also occurs if the components in the
heating system are modified from their intended use
(e.g. if the flue gas and ventilation air paths are sealed)
or if other fuels than those intended for this appliance
are used.

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Mechanical Room
General Information
During the early stages of designing a new home, we recommend that proper consideration be given to constructing a
separate mechanical room dedicated to the wood pellet fired heating equipment and domestic hot water storage tank(s),
as well as method and location of wood pellet storage facility.
The boiler must be located in a heated indoor area, near a floor drain, and as close as possible to a wall. Whenever
possible, install the boiler near an outside wall so that it is easy to duct the venting system to the boiler.
Ensure that the boiler location does not interfere with the proper circulation of combustion and ventilation air of other
fuel burning equipment within the mechanical room (if applicable).
The maximum room temperature of the mechanical room where the boiler is located must not exceed 95ºF (35ºC).
HEnsure ambient temperatures are higher than 32°F
(0°C) and lower than 95ºF (35ºC).
HPrevent the air from becoming contaminated by
halogenated hydrocarbons (e.g. as contained in paint
solvents or cleaning fluids) and excessive dust (e.g.
through grinding or polishing work). Combustion air
for the heating process, and ventilation of the boiler
room must be free of corrosive contaminants. To that
end, any boiler must be installed in an area that has no
chemical exposure. The list to the right indicates the
main, currently known sources.
HAvoid continuously high levels of humidity (e.g. through
frequent drying of laundry).
HNever close existing ventilation openings.
Sources of combustion and ventilation air contaminants
Areas likely to contain contaminants:
HNew building construction
HSwimming pools
HRemodelling areas, hobby rooms
HGarages with workshops
HFurniture refinishing areas
HDry cleaning/laundry areas and establishments
HAuto body shops
HRefrigeration repair shops
HMetal fabrication plants
HPlastic manufacturing plants
HPhoto processing plants
HBeauty salons
Products containing contaminants:
HChlorine-type bleaches, detergents and cleaning
solvents found in household laundry rooms
HPaint and varnish removers
HHydrochloric acid, muriatic acid
HChlorine-based swimming pool chemicals
HSpray cans containing chlorofluorocarbons
HChlorinated waxes and cleaners
HCements and glues
HRefrigerant leaks
HCalcium chloride used for thawing
HSodium chloride used for water softening salt
HPermanent wave solutions
HAdhesives used to fasten building products and other
similar items
HAntistatic fabric softeners used in clothes dryers
WARNING
If you notice fire coming from the appliance, call the fire
department immediately! Do not attempt to extinguish
the fire unless qualified to do so.
WARNING
Fire causes a risk of burns and explosion!
HShut down the boiler
HUse a tested fire extinguisher, class ABC.
Installation area conditions
WARNING
Incorrect ambient conditions can lead to damage to the
heating system and put safe operation at risk.
WARNING
Suffocation hazard due to carbon monoxide produced
during incomplete combustion due to lack of combustion
air. Ensure an adequate supply of fresh air. Never cover
or close vents.

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General Information
Wood Fuel Requirements
If different fuels are used, Viessmann will not assume
any liability for the functioning or service life of the boiler
plant. Refer to the “Warranty” section in the General
Terms and Conditions of Delivery.
- Burn wood pellets only
- Do not use chemicals or fluids to start fire.
- Do not burn garbage, gasoline, naphtha, engine oil, or
other inappropriate materials.
IMPORTANT
The Vitoligno 300-C is only suitable for burning wood
pellet fuels listed below.
A prerequisite for approval is of a fuel by Viessmann is the
approval for the fuel by the responsible public authorities.
Warranty claims for Viessmann Biomass boilers are
excluded if the following fuel conditions are not met.
Principles of Pellet Combustion
Pellet requirements
It is recommended that the pellets used comply with the
requirements of the Pellet Fuel Institute (PFI - Standard or
PFI - Premium) and/or CANPlus grade A1 and/or CAN/CSA
- ISO 17225 Part 2 Standard.
Requirement PFI - Standard CANPlus-A1 Specification
as per
CAN/CSA
ISO 17225-2
Grade A1
Diameter 0.230 - 0.285 in.
(5.84 - 7.25 mm)
0.236 ± 0.039 in.
(6 ± 1 mm) D06
Length A maximum
of 1% may be
longer than
1.5 in. (38 mm)
A maximum of 1%
may be longer than
1.7 in. (40 mm), but
no longer than
1.77 in. (45 mm)
0.125 to 1.575 in.
(3.15 to 40 mm)
Bulk density in delivered condition lb/cuft
(kg/m³)
38-48
(608-769)
37-47
(600 to 750)
(BD600)
Net calorific value in the delivered condition MJ/kg
kWh/kg
--
--
≥16.5
≥4.6
Q16.5
Q4.6
Water content in delivered condition m-% ≤10 ≥10 M10
Fines content in the delivered condition m-% ≤1 ≤1 F1.0
Mechanical strength in the delivered condition m-% ≥95 ≤97.5 DU 97.5
Ash content, free from water % ≤0.7 A0.7
Ash softening temperature
This value is only binding for pellets certified
to CANPlus.
It indicates the temperature at which the
wood ash is deformed and can therefore
cause fusions in the combustion chamber.
°F
(°C)
--
--
≤2200
(≤1200)
--
--
Chlorine content, free from water m-% ≤300 ppm ≤0.02 C10.2
Sulphur content, free from water m-% -- ≤0.04 S0.04
Nitrogen content, free from water m-% -- ≤0.3 N0.03
m-% = percentage by mass
What are wood pellets?
Wood pellets are made from 100 percent natural wood
remnants. This raw material is waste matter created by the
wood industry in large volumes through planing or sawing.
Wood remnants are compressed under high pressure and
formed into pellets, i.e. pressed into a cylindrical shape.
The raw material is stored and transported under completely
dry conditions. System users should also ensure completely
dry storage conditions. This is the only way to guarantee
optimum and effective combustion.
Consequence of overstepping particle size:
- Increased maintenance because of a substantially higher risk of malfunction
- Shortened service life of the conveyor augers and drives

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Pellet Quality Characteristics
General Information
High quality pellets:
Smooth shiny surface
Uniform length
Low proportion of dust
Sink in water
Low quality pellets:
Cracked rough surface
Widely varying length
High proportion of dust
Float in water
Carbon Monoxide
WARNING
The operator/ultimate owner is required to have the
heating boiler and controls checked, as a minimum once
per year, by the original installer or by a competent
heating contractor familiar with the equipment.
Defects must be corrected immediately.
For Safe operation
We recommend that you frequently:
- Check for debris which could obstruct the flow of
flue gases. The vent or chimney must not be blocked.
A blocked or partially blocked vent or chimney can
cause flue gases to leak into the structure. Flue gases
leaking into the house can cause injury or death.
Blocked or partially blocked chimneys must have the
blockage removed by a qualified heating contractor.
- Check the pressure gage for correct system (water)
pressure. Check for water on the floor from the
discharge pipe of the pressure relief valve or any other
pipe, pipe joint, valve or air vent.
- Check for moisture, water, or appearance of rust on
the flue gas pipes, their joints as well as vent dampers,
or side wall vent terminals (if so equipped).
- Ensure that nothing is obstructing the flow of
combustion and ventilation air and no chemicals,
garbage, gasoline, combustible materials, flammable
vapors and liquids are stored (not even temporarily)
in the vicinity of the boiler.
- DO NOT allow unsupervised children near the boiler.
Service/inspection of the boiler and the system must be
performed on a regular basis. Maintenance, service and
cleaning are specified in these instructions
Before the heating season begins, it is recommended that
the boiler be serviced by a qualified heating contractor.

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Boiler Connections
Installation Examples
General
The schematics on the following pages are to be seen as
guidelines only. They further do not display all system
varieties, safety devices, or concepts possible. Specific
system layouts may be further discussed with the local
Viessmann sales representative office.
CAUTION
For underfloor heating applications, an additional
immersion or strap-on aquastat must be installed in the
low temperature underfloor loop (downstream of the
mixing valve) to de-energize the pump and/or boiler to
prevent overheating. High water temperatures can
damage concrete slabs.
WARNING
If a DHW storage tank other than a Viessmann Vitocell
100 or 300 tank is used, the installer must verify proper
operation of the Viessmann DHW tank temperature
sensor with the original manufacturer of the tank.
Viessmann strongly recommends the installation of a
temperature tempering valve in the DHW supply line.
IMPORTANT
The examples on the following pages depict possible
piping layouts of the Vitoligno 300-C boiler equipped
with Viessmann System Technology.
For boiler and tank combinations, please install only
feasible combinations listed in the Viessmann Price List.
Please note that the following examples are simplified
conceptual drawings only!
Piping and necessary componentry must be field verified.
A low water cut-off (LWCO) must be installed where
required by local codes.
Proper installation and functionality in the field is the
responsibility of the heating contractor.
IMPORTANT
DHW supply and return piping between boiler DHW
connections and the Viessmann DHW tank connections,
shall be a minimum of 1¼ in. pipe size. This will ensure
the residual head of the field supplied pump is fully utilized
to overcome the resistance of the DHW heat exchanger
coil and to provide sufficient water flow to the boiler heat
exchanger.
In non-Viessmann DHW tank applications, perform, in
addition to the above, accurate calculations for DHW tank
coil pressure drop versus boiler pump (field supplied)
residual head to ensure sufficient water flow to the boiler
heat exchanger. Failure to heed the above instructions
may cause boiler short-cycling and inadequate DHW
supply.
Clearances
A minimum of 2 in. (51 mm) circumferential clearance from
non-insulated hot water pipes to combustible construction
must be maintained. In cases where the pipes are insulated
with pipe insulation of appropriate and sufficient thickness
and insulation values, the above clearance may be reduced
to 0 in. (0 mm) (refer to local codes).
Note: In the following piping layout examples all pumps
are field supplied.

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Vitoligno 300-C Installation/Service Boiler Connections
Installation Examples (continued)
Explanatory notes on the diagrams
Numbering of the technical components and the electrical
connections.

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14
Boiler Connections
System Layout 1
Applications
DHW heating by solar thermal system and pellet boiler,
central heating by pellet boiler.
Heating the heating water buffer tank
The boiler is started when a heat demand is issued to heat
the heating circuits. If the temperature at top boiler start
sensor 5falls below the set value determined by the
control unit of solid fuel boiler 2, solid fuel boiler 1
starts up. Boiler circuit pump qZ delivers the heating
water to the heating water buffer tank. Any heat not
absorbed by heating circuits rP/tP/zP/uP is stored in the
heating water buffer tank. Heating of the heating water
buffer tank is stopped as soon as bottom buffer tank
temperature sensor 6exceeds the set value determined
by the solid fuel boiler control unit.
Low temperature protection package
Solid fuel boiler 1requires a minimum return
temperature. When boiler circuit pump qZ is running, the
valve of return low temperature protection package qU
opens the route from the central heating return to boiler
1in line with the increasing return temperature and
closes the route from the boiler supply to the boiler return
(bypass).
Heating by heating water buffer tank
The heat required to heat heating circuits rP/tP/zP/uP
is taken from heating water buffer tank eP via heating
circuit pumps rQ/tQ/zQ/uQ. The respective supply
temperatures are controlled to their set value in weather-
compensated mode via 3-way mixing valves rE/tE/zE/uE.
Heating circuit control with mixing valves
The set supply temperature of every heating circuit is
determined by the following parameters:
outdoor temperature, set room temperature, operating
mode and heating curve. The supply temperature of mixing
valve circuits rP/tP/zP/uP is controlled by incremental
opening and closing of mixing valves rE/tE/zE/uE.
DHW heating by solid fuel boiler
If the set temperature for DHW determined by solid fuel
boiler control unit 2is undershot at tank temperature
sensor qQ DHW heating is activated. As soon as the
buffer tank temperature is sufficiently high, DHW
circulation pump for tank heating qW is started. To
activate tank priority control, the mixing valves in the
heating circuits can be closed and the heating circuit
pumps switched off. The type and extent of priority
control is adjustable.
Heating the dual mode DHW tank with solar energy
If the temperature differential between collector
temperature sensor wT and return temperature sensor
wZ (bottom tank temperature sensor) exceeds the set
start temperature differential, speed-controlled solar
circuit pump wE is started and the dual mode DHW tank
is heated up. If the temperature differentials reach their
shutdown thresholds, the solar circuit pump is switched
off accordingly. When the set temperature selected at
the solar control unit is reached at bottom reference
temperature sensor wZ, solar heating of the dual mode
DHW tank is stopped.

15
5790 980 - 04
Vitoligno 300-C Installation/Service Boiler Connections
System Layout 1 (continued)
Hydraulic installation
Note: This scheme is a general example without shut-off
valves or safety equipment. This does not replace
the need for on-site engineering.

Vitoligno 300-C Installation/Service
5790 980 - 04
16
Boiler Connections
System Layout 1 (continued)
Equipment required
Pos. Description
1
2
3
4
5
6
7
8
qZ
qU
qI
Heat source
Vitoligno 300-C with
Ecotronic
Outdoor temperature sensor ATS
Buffer tank temperature sensor PTS, top
Buffer tank temperature sensor PTS, centre
Buffer tank temperature sensor PTS, bottom
Safety equipment
Expansion vessel
Boiler circuit pump KKP
Return mixing valve - low temperature protection package
Low temperature protection package
qP
qQ
qW
qE
qT
DHW heating by boiler
Dual mode DHW tank
Tank temperature sensor STS
DHW pump for tank heating UPSB
DHW recirculation pump ZP
Circulation pump for transfer of heat
wQ
wW
wE
wR
wT
wZ
wU
wI
DHW heating by solar thermal system
Solar collectors
Solar Divicon
Solar circuit pump R1
Set of temperature sensors for solar circuit
– Collector temperature sensor KOL
– Tank temperature sensor SOL
High limit safety cut-out HLSC
DHW tempering valve
eP Heating water buffer tank
rP
rQ
rW
rE
Heating circuit I
Heating circuit, comprising:
Heating circuit pump HKP M1 (heating circuit I)
and...
3-way mixing valve
Stap on supply temperature sensor
Mixing valve motor M1
tP
tQ
Heating circuit II
Heating circuit distributor assembly, comprising:
Heating circuit pump HKP M2 (heating circuit II)
and...
3-way mixing valve

17
5790 980 - 04
Vitoligno 300-C Installation/Service Boiler Connections
System Layout 1 (continued)
Equipment required
Pos. Description
tP
tW
tE
tR
Heating circuit II (continued)
Strap on temperature sensor
Mixing valve motor M2
Temperature limiter to restrict the maximum temperature of underfloor heating systems
– Version with immersion sensor
– Version with contact sensor
zP
zQ
zW
zE
Heating circuit III
Heating circuit, comprising:
Heating circuit pump HKP M3 (heating circuit III)
and...
3-way mixing valve
Strap on temperature sensor
Mixing valve motor M3
uP
uQ
uW
uE
Heating circuit IIII
Heating circuit distributor assembly, comprising:
Heating circuit pump HKP M4 (heating circuit IIII)
and...
3-way mixing valve
Strap on temperature sensor
Mixing valve motor M4
uZ
uU
uI
uO
iQ
iW
iE
iR
Accessories
Vitotrol 200A (max. two Vitotrol 200A per Ecotronic)
or...
Vitotrol 300A (max. one Vitotrol 300A per Ecotronic)
or...
Vitotrol 350
Low water cutoff
KM BUS distributor
Output feedback
External default output
External demand
ON/OFF switch

Vitoligno 300-C Installation/Service
5790 980 - 04
18
Boiler Connections
System Layout 1 (continued)
Electrical installation

19
5790 980 - 04
Vitoligno 300-C Installation/Service Boiler Connections
System Layout 1 (continued)
Electrical installation (continued)

Vitoligno 300-C Installation/Service
5790 980 - 04
20
Boiler Connections
System Layout 2
Applications
DHW heating and central heating by pellet boiler
Heating the heating water buffer tank
The boiler is started when a heat demand is issued to heat
the heating circuits. If the temperature at top boiler start
sensor 1falls below the set value determined by the
control unit of solid fuel boiler 2, solid fuel boiler 1 starts
up. Boiler circuit pump qZ delivers the heating water to the
heating water buffer tank. Any heat not absorbed by heating
circuits rP/tP is stored in the heating water buffer tank.
Heating of the heating water buffer tank is stopped as soon
as bottom buffer tank temperature sensor 6exceeds the
set value determined by the solid fuel boiler control unit.
Low temperature protection package
Solid fuel boiler 1requires a minimum return
temperature. When boiler circuit pump qZ is running, the
valve of return low temperature protection package qU
opens the route from the central heating return to boiler
1in line with the increasing return temperature and
closes the route from the boiler supply to the boiler return
(bypass).
Heating by heating water buffer tank
The heat required to heat heating circuits rP/tP is taken
from heating water buffer tank eP via heating circuit
pumps rQ/tQ. The respective supply temperatures are
controlled to their set value in weather-compensated
mode via 3-way mixing valves rE/tE.
Heating circuit control with mixing valves
The set supply temperature of every heating circuit is
determined by the following parameters: outdoor
temperature, set room temperature, operating mode and
heating curve. The supply temperature of mixing valve
circuits rP/tP is controlled by incremental opening and
closing of mixing valves rE/tE.
DHW heating by solid fuel boiler
When the set temperature for DHW determined by solid
fuel boiler control unit 2is undershot at tank temperature
sensor qQ, DHW heating is activated. As soon as the buffer
tank temperature is sufficiently high, DHW circulation pump
for tank heating qW is started. To activate tank priority
control, the mixing valves in the heating circuits can be
closed and the heating circuit pumps switched off.
The type and extent of priority control is adjustable.