Fröling S3 Turbo 15 User manual

Operating Instructions
Firewood boiler S3 Turbo
Translation of the original German operating instructions for the operator
Read and follow the instructions and safety information!
Technical changes, typographical errors and omissions reserved!
B0610919_en | Edition 07/05/2019
Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

Table of contents
1 General 5
1.1 Operating principle 5
1.2 S3 Turbo Product Overview 6
2 Safety 8
2.1 Hazard levels of warnings 8
2.2 General safety information 9
2.3 Permitted uses 10
2.3.1 The Clean Air Act 1993 and Smoke Control Areas 10
2.3.2 Permitted fuels 11
Firewood 11
2.3.3 Fuels permitted under certain conditions 11
Wood briquettes 11
2.3.4 Non-permitted fuels 13
2.4 Qualification of operating staff 13
2.5 Protective equipment for operating staff 13
2.6 Safety devices 14
2.7 Residual risks 15
2.8 Emergency procedure 16
2.8.1 Overheating of the system 16
2.8.2 Smell of flue gas 16
2.8.3 Power failure / induced draught fan failure 17
2.8.4 Fire in the system 17
3 Notes for operating a heating system 18
3.1 Installation and approval of the heating system 18
3.2 General information for installation room (boiler room) 18
3.3 Requirements for central heating water 19
3.4 Notes for using pressure maintenance systems 20
3.5 Return lift 21
3.6 Combination with storage tank 21
3.7 Chimney connection/chimney system 21
4 Operating the system 22
4.1 Assembly and initial startup 22
4.2 Switching on the power supply 23
4.3 Switching on the boiler 23
4.4 Before heating up the boiler 23
4.4.1 Operating the WOS lever 23
4.4.2 Reloading intervals when operating with storage tank 23
4.4.3 Determining the right amount of fuel 24
4.4.4 Fuel table 25
4.4.5 Fill level in boiler 25
4.4.6 Reloading intervals when operating without storage tank or if the storage tank is too small 25
Table of contents
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4.5 Heat up firewood manually 26
4.6 Operate boiler using the button display 27
4.7 Reloading firewood 28
4.8 Switching off the boiler 29
4.9 Switching off the power supply 29
4.10 Checking the ash level in the boiler 30
4.10.1 Removing ash 30
4.10.2 Clean the grating 31
5 Servicing the system 32
5.1 General information on servicing 32
5.2 Required tools 33
5.3 Maintenance work by the operator 34
5.3.1 Inspection 34
Checking the system pressure 34
Checking the thermal discharge safety device 34
Checking the safety valve 34
Checking the quick vent valve 34
5.3.2 Periodic inspection and cleaning 35
Cleaning the flue gas temperature sensor 35
Cleaning the carbonisation gas duct 35
Checking the primary air openings 36
Clean the heat exchanger pipes 37
Cleaning the flue gas pipe 38
Checking the draught controller flap 39
Checking the seal on the doors 39
Cleaning the induced draught fan 40
5.4 Maintenance work by technicians 41
5.4.1 Cleaning the Lambda probe 42
5.5 Emissions measurement by chimney sweep or regulatory body 43
5.5.1 General information on measurement 43
5.5.2 Performing the emissions measurement 44
Create the measurement conditions and perform the measurement 44
Start emissions measurement 44
5.6 Replacement parts 45
5.7 Disposal information 45
5.7.1 Disposal of the ash 45
5.7.2 Disposal of system components 45
6 Troubleshooting 46
6.1 General fault with power supply 46
6.1.1 Behaviour of system after a power failure 46
6.2 Excessive temperature 46
6.3 Faults with fault message - Key control 47
6.3.1 Troubleshooting 47
Procedure for fault messages 47
6.4 Acknowledging a fault message 48
7 Notes 49
Table of contents
Operating Instructions S3 Turbo | B0610919_en 3

8 Appendix 52
8.1 Addresses 52
8.1.1 Address of manufacturer 52
Customer service 52
8.1.2 Address of the installer 52
Table of contents
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1 General
Thank you for choosing a quality product from Froling. The product features a state-of-
the-art design and conforms to all currently applicable standards and testing
guidelines.
Please read and observe the documentation provided and always keep it close to the
system for reference. Observing the requirements and safety information in the
documentation makes a significant contribution to safe, appropriate, environmentally
friendly and economical operation of the system.
The constant further development of our products means that there may be minor
differences from the pictures and content. If you discover any errors, please let us
know: [email protected].
Subject to technical change.
Warranty and Guarantee Conditions
Our sale and delivery conditions will be applicable. These conditions have been made
available to customers, and customers have been made aware of them at the time of
order completion.
You can also find the guarantee conditions on the enclosed guarantee certificate.
1.1 Operating principle
The Froling S3 Turbo is a wood boiler for the non-condensing combustion of firewood.
The fuel loading chamber is filled with fuel via the fuel loading door located behind the
heat insulated door on the front of the boiler. The combustion grate, through which the
combustion gases are sucked into the combustion chamber by the induced draught
fan, is located below the fuel loading chamber. When the induced draught fan is used,
the combustion air around the pre-heating chamber door is sucked in and channelled
to the fuel via regulating flaps on the side air boxes (primary and secondary air). The
boiler water and flue gas temperature are regulated by the induced draught fan. The
primary air is used to adjust the boiler to the fuel and set the required output. The
secondary air is used to set the combustion performance which can be done optionally
using the manual adjuster or the Lambda probe and servo-motor. The flue gas travels
through the heat exchanger to the flue gas outlet, where there is a slight overpressure
at the connection between the connecting piece and the chimney system when the
boiler is operating at nominal load. In order to optimise heat transfer and for cleaning
purposes, the heat exchanger pipes are fitted with a manual efficiency optimisation
system (WOS), which can be operated using a lever on the outside of the boiler. The
ash deposits at the bottom of the combustion chamber and below the heat exchanger
pipes can be removed via the combustion chamber door on the front of the boiler.
General 1
Operating principle
Operating Instructions S3 Turbo | B0610919_en 5

1.2 S3 Turbo Product Overview
1Insulated door
1.1 Maintenance overview
2Fuel loading door
3Pre-heating chamber door
4Combustion chamber door with inspection glass
5S-Tronic Plus / S-Tronic Lambda controller
5.1 Visual display showing operating statuses and parameters
5.2 Status LED to display the operating status:
- GREEN constant: BOILER ACTIVE (heating up/heating)
- GREEN flashing (interval: 5 sec OFF, 1 sec ON): OFF
- ORANGE flashing: WARNING
- RED flashing: FAULT
5.3 Navigation keys to move around in the menus and to change the parameter values
5.4 Function keys to call up individual boiler functions directly
NOTICE! For key layout see operating instructions for boiler controller
1General
S3 Turbo Product Overview
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Underneath the back insulating cover (9):
6Lever of the heat exchanger cleaner (WOS system)
7 For S-Tronic Plus: Manual adjusters for primary and secondary air
For S-Tronic Lambda: Servo-motors for primary and secondary air
(Air duct system set by qualified technician during initial start-up)
8Cleaning door
9Back insulating cover
10 Heat exchanger cover: Maintenance opening for cleaning the WOS system and heat
exchanger
11 STL high-limit thermostat
12 Main switch
General 1
S3 Turbo Product Overview
Operating Instructions S3 Turbo | B0610919_en 7

2 Safety
2.1 Hazard levels of warnings
This documentation uses warnings with the following hazard levels to indicate direct
hazards and important safety instructions:
DANGER
The dangerous situation is imminent and if measures are not observed it will lead
to serious injury or death. You must follow the instructions!
WARNING
The dangerous situation may occur and if measures are not observed it will lead
to serious injury or death. Work with extreme care.
CAUTION
The dangerous situation may occur and if measures are not observed it will lead
to minor injuries.
NOTICE
The dangerous situation may occur and if measures are not observed it will lead
to damage to property or pollution.
2Safety
Hazard levels of warnings
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2.2 General safety information
DANGER
If the device is used incorrectly:
Incorrect use of the system can cause severe injury and damage.
When operating the system:
❒ Observe the instructions and information in the manuals.
❒ Observe the details on procedures for operation, maintenance and cleaning,
as well as troubleshooting in the individual manuals.
❒ Any work above and beyond this should be carried out by authorised heating
engineers or by Froling customer services.
WARNING
External influences:
Negative external influences, such as insufficient combustion air or non-standard
fuel, can cause serious faults in combustion (e.g. spontaneous combustion of
carbonisation gases or flash fires) which can in turn cause serious accidents!
When operating the boiler, please note the following:
❒ Instructions and information regarding versions and minimum values, as well
as standards and guidelines for heating components in the instructions must
be observed.
WARNING
Severe injuries and damage can be caused by an inadequate flue gas system.
Problems with the flue gas system, such as poor cleaning of the flue pipe or
insufficient chimney draught, can cause serious faults in combustion (such as
spontaneous combustion of carbonisation gases or flash fires).
Take the following precautions:
❒ Optimum boiler performance can only be guaranteed if the flue gas system is
functioning correctly.
Safety 2
General safety information
Operating Instructions S3 Turbo | B0610919_en 9

2.3 Permitted uses
The Froling Firewood boiler S3 Turbo is designed solely for heating domestic water.
Only the fuels specified in the "Permitted fuels" section may be used.
⇨ See "Permitted fuels" [page 11]
The unit should only be operated when it is in full working order. It must be operated in
accordance with the instructions, observing safety precautions, and you should ensure
you are aware of the potential hazards. The inspection and cleaning intervals in the
operating instructions must be observed. Ensure that any faults which might impair
safety are rectified immediately.
The manufacturer or supplier is not liable for any damage resulting from non-permitted
uses.
Only original spare parts or specific alternative spare parts authorised by the
manufacturer may be used. Any kind of change or modification made to the product
will invalidate the manufacturer’s conformity with the applicable guideline(s). In such
cases, the product will need to undergo new hazard evaluation procedures by the
operator. The operator will then be fully responsible for the declaration of conformity
according to the valid guideline(s) for the product and will need to issue a
corresponding declaration for the device. This person will then assume all of the rights
and responsibilities of a manufacturer.
2.3.1 The Clean Air Act 1993 and Smoke Control Areas
Under the Clean Air Act local authorities may declare the whole or part of the district of
the authority to be a smoke control area. It is an offence to emit smoke from a
chimney of a building, from a furnance or from any fixed boiler if located in a
designated smoke control area. It is also an offence to acquire an „unauthorised
fuel“ for use within a smoke control area unless it is used in an „exempt“ appliance
(„exempted“ from the controls which generally apply in the smoke control area). The
Secretary of State for Environment, Food and Rural Affairs has powers under the Act
to authorise smokeless fuels or exempt appliances for use in smoke control areas in
England. In Scotland and Wales this power rests with Ministers in the devolved
administrations for those countries. Separate legislation, the Clean Air (Northern
Ireland) Order 1981, applies in Northern Ireland. Therefore it is a requirement that
fuels burnt or obtained for use in smoke control areas have been „authorised“ in
Regulations and that appliances used to burn solid fuel in those areas (other than
„authorised“ fuels) have been exempted by an Order made and signed by the
Secretary of State or Minister in the devolved administrations.
Further information on the requirements of the Clean Air Act can be found here: http://
smokecontrol.defra.gov.uk
Your local authority is responsible for implementing the Clean Air Act 1993 including
designation and supervision of smoke control areas and you can contact them for
details of Clean Air Act requirements.
The Froling S1 Turbo 15 and S1 Turbo 20 have been recommended as suitable for
use in smoke control areas when burning fuels as listed under "Permitted fuels".
The Froling S3 Turbo 18, S3 Turbo 28, S3 Turbo 36 and S3 Turbo 45 have been
recommended as suitable for use in smoke control areas when burning fuels as listed
under "Permitted fuels".
2Safety
Permitted uses
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2.3.2 Permitted fuels
Firewood
Firewood up to max. 55 cm long.
Water content (w) greater than 15% (equivalent to wood moisture u > 17%)
Water content (w) less than 25% (equivalent to wood moisture u < 33%)
EU: Fuel as per EN ISO 17225 – Part 5: Firewood class A2 / D15 L50
Additional for
Germany: Fuel class 4 (§3 of the First Federal Emissions Protection Ordinance
(BimSchV) in the last amended version)
▪ Use wind-exposed areas where possible for storage (e.g. store at edge of forest instead
of in forest)
▪ Walls of buildings facing the sun are ideal
▪ Create a dry underlay, where possible with air access (line with round timber, pallets,
etc.)
▪ stack split wood and store in such a way that it is protected from the elements
▪ If possible, stock fuel for the day in a warm place (e.g. in boiler room) (pre-heats the
fuel!)
Storage time dependent upon water content
Wood type Water content
15 – 25% less than 15
%
Storage in heated and ventilated room
(approx. 20°C)
Soft wood (e.g.
spruce)
approx.
6 months
from 1 year
Hardwood (e.g.
beech)
1 – 1.5 years from 2 years
Outdoor storage (protected from
elements, exposed to wind)
Soft wood (e.g.
spruce)
2 summers from 2 years
Hardwood (e.g.
beech)
3 summers from 3 years
Freshly cut wood has an approximate water content of 50 to 60%. As the above table
shows, the water content of the firewood decreases the longer the wood is stored
depending on how dry and warm the storage location is. The ideal water content of
firewood is between 15 and 25%. If the water content falls below 15%, we recommend
you adjust the combustion control to the fuel.
2.3.3 Fuels permitted under certain conditions
Wood briquettes
Wood briquettes for non-industrial use with a diameter of 5-10 cm and 5-50 cm long.
Water content
Note on standards
Tips for
storing wood
Safety 2
Permitted uses
Operating Instructions S3 Turbo | B0610919_en 11

EU: Fuel as per EN ISO 17225 - Part 3:
wood briquettes class B / D100 L500 Form 1 - 3
Additional for
Germany: Fuel class 5a (§3 of the First Federal Emissions Protection Ordinance
(BImSchV) - applicable version)
▪ When burning wood briquettes use the settings for extremely dry fuel
▪ Wood briquettes must be heated up with firewood as per EN ISO 17225-5
(at least two layers of firewood under the wood briquettes)
▪ The fuel loading chamber must not be filled more than 3/4 full, as the wood briquettes
expand during combustion
▪ Even when using the settings for dry fuel, burning wood briquettes can cause
combustion problems. In such cases, repairs must be carried out by qualified staff.
Please contact Froling customer services or your installer.
Note on standards
Notes on
use
2Safety
Permitted uses
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2.3.4 Non-permitted fuels
The use of fuels not defined in the "Permitted fuels" section, and particularly the
burning of refuse, is not permitted.
CAUTION
In case of use of non-permitted fuels:
Burning non-permitted fuels increases the cleaning requirements and leads to a
build-up of aggressive sedimentation and condensation, which can damage the
boiler and also invalidates the guarantee. Using non-standard fuels can also lead
to serious problems with combustion.
For this reason, when operating the boiler:
❒ Only use permitted fuels
2.4 Qualification of operating staff
CAUTION
If unauthorised persons enter the Installation room:
Risk of personal injury and damage to property
❒ The operator is responsible for keeping unauthorised persons, in particular
children, away from the system.
Only trained operators are permitted to operate the unit. The operator must also have
read and understood the instructions in the documentation.
2.5 Protective equipment for operating staff
You must ensure that staff have the protective equipment specified by accident
prevention regulations!
▪ For operation, inspection and cleaning:
- suitable work wear
- protective gloves
- sturdy shoes
- dust mask
Safety 2
Permitted uses
Operating Instructions S3 Turbo | B0610919_en 13

2.6 Safety devices
Underneath the back insulating cover:
11 HIGH-LIMIT THERMOSTAT (STL) (protection against overheating)
The STL switches off the combustion system when the boiler reaches 105°C. The
pumps continue to run. Once the temperature falls below approx. 75°C, the STL can
be reset mechanically.
12 MAIN SWITCH (switches off the power supply)
For shutting down the entire system
❒ The power to all components is switched off.
➥ WARNING! Only switch off the boiler when the fuel has burnt down and the
boiler has cooled off.
TA THERMAL DISCHARGE VALVE (protection against overheating)
The thermal discharge valve opens at approx. 100°C and feeds cold water to the
safety heat exchanger to lower the boiler temperature
SV SAFETY VALVE (protection against overheating/excess pressure)
When the boiler pressure reaches a maximum of 3 bar, the safety valve opens and the
heated water is blown off in the form of steam.
2Safety
Safety devices
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2.7 Residual risks
WARNING
When the main switch is switched off in heating mode:
The boiler is not controlled. Any resulting boiler malfunctions can cause serious
injury and damage.
Take the following precautions:
❒ Allow the fire to burn out completely and let the boiler cool
➥ID fan switches off when "Off" status has been reached
(flue gas temperature < 80°C, boiler temperature < 65°C)
❒ Only then is it safe to switch off the main switch
WARNING
When touching hot surfaces:
Severe burns are possible on hot surfaces and the flue gas pipe!
When work is carried out on the boiler:
❒ Shut down the boiler according to procedure (“Off” operating status) and allow
it to cool down
❒ Protective gloves must usually be worn for work on the boiler, and it should
only be operated using the handles provided
❒ Insulate the flue gas pipes and do not touch them during operation
WARNING
If you open the combustion chamber door, pre-heating door, fuel loading door
during operation:
This may result in injury, damage or flue gas generation!
Therefore:
❒ Never open the combustion chamber door or pre-heating chamber door
during operation
❒ The fuel loading door must be kept closed during operation and may only be
opened briefly during reloading intervals
WARNING
When inspecting and cleaning the boiler with the main switch on:
Serious injuries possible due to boiler/individual components starting up
automatically (induced draught)!
Before inspection and cleaning work in/on the boiler:
❒ Allow the fuel in the boiler to burn off
❒ Allow boiler to cool off and switch off main switch
Safety 2
Residual risks
Operating Instructions S3 Turbo | B0610919_en 15

WARNING
If non-permitted fuel types are used:
Non-standard fuels can cause serious faults in combustion (e.g. spontaneous
combustion of carbonisation gases / flash fires) which can lead to serious
accidents!
Take the following precautions:
❒ Only use fuels specified in the "Permitted fuels" section of these operating
instructions.
2.8 Emergency procedure
2.8.1 Overheating of the system
If the system overheats and the safety devices fail to operate, proceed as follows:
NOTICE! Do not under any circumstances switch off the main switch or disconnect the
power supply!
❒ Keep all the doors on the boiler closed
❒ Open all mixing valve taps, switch on all pumps.
➥The Froling heating circuit control takes on this function in automatic operation.
❒ Leave the boiler room and close the door
❒ Open any thermostatic valves on the radiator and ensure sufficient heat
dissipation from the rooms
If the temperature does not drop:
❒ Contact the installer or Froling customer services
⇨ See "Addresses" [page 52]
2.8.2 Smell of flue gas
DANGER
If you smell flue gas in the boiler room:
Inhaling toxic flue gas can potentially be fatal!
If you smell flue gas in the room where the boiler is installed:
❒ Keep all the doors on the boiler closed
❒ Ventilate the room where the boiler is installed
❒ Close the fire door and doors to living areas
❒ Allow the fire to burn out completely and let the boiler cool
Recommendation: Do not install smoke alarms and carbon monoxide detectors near
the system.
2Safety
Emergency procedure
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2.8.3 Power failure / induced draught fan failure
A power failure, among others, can be identified based on the following points:
▪ Display remains dark despite touching it
▪ LED status does not flash / light up
▪ No noise from the units (e.g. induced draught fan) can be heard
If the induced draught fan fails when there is power supply, the display shows the
error message “ID fan does not rotate, in spite of full
activation”.
DANGER
In the event of a power failure or induced draught fan failure during heating mode:
The boiler is placed in an uncontrolled state. Life-threatening injury is possible
when opening the doors.
What to do in the event of a power failure / induced draught fan failure:
❒ Keep all the doors on the boiler closed
❒ Ventilate the room where the boiler is installed
❒ Close the fire door and doors to living areas
❒ Allow the fire to burn out completely and let the boiler cool
Recommendation: Equip the boiler with an uninterruptible power supply (USV,
photovoltaic system, etc.). This ensures correct combustion of the firewood and
prevents possible uncontrolled conditions (tarring of the heat exchanger, etc.).
Recommendation: Do not install smoke alarms and carbon monoxide detectors near
the system.
2.8.4 Fire in the system
DANGER
In case of fire in the system:
Risk of death by fire and poisonous gases
Emergency procedure in case of fire:
❒ Leave the boiler room
❒ Close the doors
❒ Inform the fire department
Safety 2
Emergency procedure
Operating Instructions S3 Turbo | B0610919_en 17

3 Notes for operating a heating system
Carrying out modifications to the system and changing or disabling safety equipment
is prohibited.
Always comply with all fire, building and electrical regulations when installing or
operating the system, in addition to following the operating instructions and mandatory
regulations that apply in the country in which the tank is operated.
3.1 Installation and approval of the heating system
The boiler should be operated in a closed heating system. The following standards
govern the installation:
EN 12828 - Heating Systems in Buildings
NOTICE! Each heating system must be officially approved.
The appropriate supervisory authority (inspection agency) must always be informed
when installing or modifying a heating system, and authorisation must be obtained
from the building authorities:
Austria: report to the construction authorities of the community or magistrate
Germany: report new installations to an approved chimney sweep / the building
authorities.
3.2 General information for installation room (boiler room)
Boiler room characteristics
▪ The floor must be even, clean and dry and have an adequate load-bearing
capacity.
▪ There must not be a potentially explosive atmosphere in the boiler room as the
boiler is not suitable for use in potentially explosive environments.
▪ The boiler room must be frost-free.
▪ The boiler does not provide any light, so the customer must ensure sufficient
lighting in the boiler room in accordance with national workplace design
regulations.
▪ When using the boiler above 2000 metres above sea level you should consult the
manufacturer.
▪ Danger of fire due to flammable materials.
The floor of the boiler room must not be flammable. No flammable materials
should be stored near the boiler. Flammable objects (e.g. clothing) must not be put
on the boiler to dry.
▪ Damage due to impurities in combustion air.
Do not use any solvents or cleaning agents containing chlorine and hydrogen
halides in the room where the boiler is installed (e.g. chlorination units for
swimming pools).
▪ Keep the air suction opening of the boiler free of dust.
Note on standards
3Notes for operating a heating system
Installation and approval of the heating system
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▪ The system must be protected against the chewing or nesting of animals (e.g.
rodents etc.).
Ventilation of the boiler room
Ventilation air for the boiler room should be taken from and expelled directly outside,
and the openings and air ducts should be designed to prevent weather conditions
(foliage, snowdrifts, etc.) from obstructing the air flow.
Unless otherwise specified in the applicable building regulations for the boiler room,
the following standards apply to the design and dimensions of the air ducts:
ÖNORM H 5170 - Construction and fire protection requirements
3.3 Requirements for central heating water
Unless contrary to other national regulations, the latest versions of the following
standards and guidelines apply:
Austria:
Germany:
ÖNORM H 5195
VDI 2035
Switzerland
:
Italy:
SWKI BT 102-01
UNI 8065
Observe the standards and also follow the recommendations below:
❒ Aim for a pH value of between 8.2 and 10.0. If the central heating water comes
into contact with aluminium, the pH value must be between 8.0 and 8.5
❒ Use prepared water which complies with the standards cited above for filling and
make-up water
❒ Avoid leaks and use a closed heating system to maintain water quality during
operation
❒ When filling with make-up water, always bleed the filling hose before connecting,
in order to prevent air from entering the system
Advantages of prepared water:
▪ Complies with the applicable standards
▪ Less of a drop in output due to reduced limescale build-up
▪ Less corrosion due to fewer aggressive substances
▪ Long-term cost savings thanks to improved energy efficiency
Note on standards
Notes for operating a heating system 3
General information for installation room (boiler room)
Operating Instructions S3 Turbo | B0610919_en 19

Permitted water hardness for the fill and make-up water in accordance with VDI 2035:
Overall heat
output
Total hardness at
<20 l/kW minimum
individual heat output 1)
Total hardness at
>20 <50 l/kW minimum
individual heat output 1)
Total hardness at
>50 l/kW minimum
individual heat output 1)
kW °dH mol/m³ °dH mol/m³ °dH mol/m³
<50 no demand or 11.2 2 0.11 0.02
<16.8 2) <3 2)
>5 <200 11.2 2 8.4 1.5
>200 <600 8.4 1.5 0.11 0.02
>600 0.11 0.02
1.From specific system volume (litres nominal capacity/heat output; for multi-boiler systems use the smallest individual heat output)
2.In the case of systems with central heating boilers and for systems with electric heating elements
Additional requirements for Switzerland
The filling and make-up water must be demineralised (fully purified)
▪ The water must not contain any ingredients that could settle and accumulate in the
system
▪ This makes the water non-electroconductive, which prevents corrosion
▪ It also removes all the neutral salts such as chloride, sulphate and nitrate which can
weaken corrosive materials in certain conditions
If some of the system water is lost, e.g. during repairs, the make-up water must also be
demineralised. It is not enough to soften the water. The heating system must be
professionally cleaned and rinsed before filling the units.
Inspection:
▪ After eight weeks, the pH value of the water must be between 8.2 and 10.0. If the central
heating water comes into contact with aluminium, the pH value must be between 8.0 and
8.5
▪ Yearly. Values must be recorded by the owner
3.4 Notes for using pressure maintenance systems
Pressure maintenance systems in hot-water heating systems keep the required
pressure within predefined limits and balance out volume variations caused by
changes in the hot-water temperature. Two main systems are used:
Compressor-controlled pressure maintenance
In compressor-controlled pressure maintenance units, a variable air cushion in the
expansion tank is responsible for volume compensation and pressure maintenance. If
the pressure is too low, the compressor pumps air into the tank. If the pressure is too
high, air is released by means of a solenoid valve. The systems are built solely with
closed-diaphragm expansion tanks to prevent the damaging introduction of oxygen
into the heating water.
3Notes for operating a heating system
Notes for using pressure maintenance systems
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