Fröling PE1 Pellet 7 User manual

Operating Instructions
Pellet boiler PE1 Pellet 7-35 / PE1 Pellet Unit 7-20
PE1 Pellet 7-35 PE1 Pellet Unit 7-20
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!
B1001020_en | Edition 24/02/2021
Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

Contents
1 General 5
1.1 PE1 Pellet product overview 6
2 Safety 7
2.1 Hazard levels of warnings 7
2.2 Pictograms used 8
2.3 General safety information 9
2.4 Permitted uses 10
2.4.1 The Clean Air Act 1993 and Smoke Control Areas 10
2.4.2 Permitted fuels 11
Wood pellets 11
2.4.3 Non-permitted fuels 12
2.5 Qualification of operating staff 12
2.6 Protective equipment for operating staff 12
2.7 Safety Devices 13
2.8 Residual risks 14
2.9 Emergency procedure 15
2.9.1 Overheating of the system 15
2.9.2 Smell of flue gas 15
2.9.3 Fire in the system 15
3 Notes for operating a heating system 16
3.1 Installation and approval of the heating system 16
3.2 General information for installation room (boiler room) 16
3.3 Room air-independent operation 17
3.4 Requirements for central heating water 18
3.5 Notes for using pressure maintenance systems 20
3.6 Use 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 Operate the boiler using the touch display 23
4.3.1 Overview of the touch display 23
Status display 24
Control icons 24
Display icons for froeling-connect/remote control 25
Navigation within the system menu 26
Changing parameters 27
Change time window 27
Quick menu 28
4.3.2 Select information displays 29
4.3.3 Switch boiler ON/OFF 31
4.3.4 Change boiler mode 32
Contents
2 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

4.3.5 Change date and time 32
4.3.6 Change desired DHW tank temperature 33
4.3.7 One-time extra loading of an individual DHW tank 33
4.3.8 One-time extra loading of all existing DHW tanks. 33
4.3.9 Set the heating curve of a heating circuit 34
4.3.10 Change room temperature (heating circuit without room temperature sensor) 35
4.3.11 Change room temperature (heating circuit with room temperature sensor) 36
4.3.12 Switch heating circuit mode 36
4.3.13 Lock display/switch user level 37
4.3.14 Change the name of the components 37
4.3.15 Configure the holiday program 38
4.4 Switch the boiler ON/OFF on the room console 39
4.5 Filling the pellet store 40
4.5.1 Notes on filling the fuel stores 40
4.5.2 Correct the remaining pellet amount in store room 41
4.5.3 Adjust the pellet consumption counter to the fuel 41
4.5.4 Setting the automatic notification for minimum level 43
4.5.5 Resetting the pellet consumption counter 44
4.6 Checking the fill level of the ash container and emptying if required 44
4.6.1 Check the fill level of the ash container 45
4.6.2 Empty ash container 46
4.7 Switching off the power supply 46
5 Servicing the system 47
5.1 General information on servicing 47
5.2 Required tools 48
5.3 Maintenance work by the operator 49
5.3.1 Inspection 49
Checking the system pressure 49
Checking the safety valve 49
Checking the quick vent valve 49
5.3.2 Cleaning 50
Cleaning the burn-out tray, burner insert and combustion chamber 50
5.3.3 Periodic inspection and cleaning 51
Clean the induced draft fan 51
Clean the heat exchanger and WOS springs 52
Cleaning the flue gas pipe 53
Checking the draught controller flap 53
5.4 Servicing the DHW tank unit (optional) 54
5.4.1 Safety devices 54
5.4.2 Pressure reducing valve 54
5.4.3 Magnesium corrosion protection anode 55
5.4.4 Interior cleaning / removing limescale deposits 56
5.5 Servicing the condensing boiler heat exchanger (optional) 57
5.5.1 Inspecting the heat exchanger 57
5.5.2 Checking the condensation drain 58
5.6 Maintenance work by technicians 59
5.6.1 Checking and cleaning the combustion grate 60
5.6.2 Cleaning the measurement line of the underpressure controller 61
5.6.3 Cleaning the Lambda probe 62
5.7 Emissions measurement by chimney sweep or regulatory body 63
5.7.1 Switch on the system 63
5.7.2 Start emissions measurement 64
Contents
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 3

5.8 Replacement parts 64
5.9 Disposal information 64
5.9.1 Disposal of the ash 64
5.9.2 Disposal of system components 64
6 Troubleshooting 65
6.1 General fault with power supply 65
6.1.1 Behaviour of system after a power failure 65
6.2 Excessive temperature 65
6.3 Faults with fault message 66
6.3.1 Procedure for fault messages 66
7 Appendix 68
7.1 Addresses 68
7.1.1 Address of manufacturer 68
Customer service 68
7.1.2 Address of the installer 68
Contents
4 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

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.
General 1
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 5

1.1 PE1 Pellet product overview
7.1
81
34
5
2.1
2.2
2.3
2.4
2.3
2.
4
0
1
6
6.1
1PE1 Pellet pellet boiler
2Lambdatronic P 3200 boiler controller, ⇨ See "Overview of the touch display" [page
23]
2.1 Large touch screen for displaying / modifying operating statuses and parameters
2.2 Status display (Operating status), ⇨ See "Status display" [page 24]
2.3 Brightness sensor for automatically adjusting the brightness of the display
2.4 USB port for connecting a USB stick for software updates
3Main switch
4High-limit thermostat (STL)
5Door switch
6Maintenance opening for combustion chamber (underneath the cover)
6.1 Inspection glass for checking combustion
7.1 Ash container for automatic ash removal
8Quick start guide
1General
PE1 Pellet product overview
6 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

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.
Safety 2
Hazard levels of warnings
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 7

2.2 Pictograms used
The following symbols are used in the documentation and/or on the boiler to show
what is required and forbidden and to give warnings.
In accordance with the Machinery Directive, signs fitted directly within the danger area
of the boiler indicate immediate hazards or safety procedures. These stickers must not
be removed or covered.
Refer to the operating
instructions
Wear safety shoes
Wear protective gloves Turn off the main switch
Keep the doors closed Wear a dust mask
Work under the supervision of a
second person
Lock
Unauthorised access prohibited No fire, open flames or smoking
Warning - hot surface Warning - hazardous electrical
voltage
Warning - hazardous or irritant
materials
Warning - automatic boiler
startup
Warning of injury to fingers or
hands, automatic fan
Warning of injury to fingers or
hands, automatic screw
Warning of injury to fingers or
hands, gear/chain drive
Warning of injury to fingers or
hands, cutting edge
Hand injury warning Warning of injury from being
pulled into rotating shafts
Increased CO concentration
warning
Slipping hazard warning
2Safety
Pictograms used
8 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

2.3 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 respective manuals.
❒ Any work above and beyond this (e.g. servicing) must be carried out by a
heating engineer approved by Fröling Heizkessel- und Behälterbau GesmbH
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 PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 9

2.4 Permitted uses
The Froling Pellet boiler PE1 Pellet 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.
2.4.1 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 PE1 Pellet 7, PE1 Pellet 10, PE1 Pellet 15, PE1 Pellet 20, PE1 Pellet 25,
PE1 Pellet 30 and PE1 Pellet 35 have been recommended as suitable for use in
smoke control areas when burning fuels as listed under "Permitted fuels".
2Safety
Permitted uses
10 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

2.4.2 Permitted fuels
Wood pellets
Wood pellets made from natural wood with a diameter of 6 mm
EU: Fuel acc. to EN ISO 17225 - Part 2: Wood pellets class A1 / D06
and/or: EN
plus / DIN plus certification scheme
General note:
Before refilling the store, check for pellet dust and clean if necessary.
TIP: Fit the Froling PST pellet deduster for separating the dust particles contained in
the return air
Note on standards
Safety 2
Permitted uses
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 11

2.4.3 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
2.5 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.
2.6 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
2Safety
Permitted uses
12 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

2.7 Safety Devices
34
5
2.1
0
1
SV
2.1 BOILER OFF
(switches off the boiler to prevent overheating)
❒ Tap “Boiler OFF"
➥Automatic mode is switched off
➥Control system follows the boiler shutdown procedure
➥Pumps continue to run
3 MAIN SWITCH
(switches off the power supply)
Before carrying out work on/in the boiler:
❒ Tap “Boiler OFF"
➥Automatic mode is switched off
➥Control system follows the boiler shutdown procedure
❒ Switch off the main switch and let the boiler cool down
4 SAFETY TEMPERATURE LIMITER (STL)
(protection against overheating)
The STL (high-limit thermostat) switches off the combustion system when the boiler
reaches 100°C. The pumps continue to run. Once the temperature falls below approx.
75°C, the STL can be reset mechanically.
5 DOOR SWITCH
(protection against access to moving components)
If the insulated door opens while the boiler is operating, all of the units stop to prevent
injuries at moving components. If the insulated door remains open for more than 10
seconds, the boiler is switched off automatically.
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.
Safety 2
Safety Devices
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 13

2.8 Residual risks
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 (“Boiler 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
When inspecting and cleaning the boiler with the main switch on:
Serious injuries possible due to automatic boiler startup!
Before inspection and cleaning work in/on the boiler:
❒ Switch the boiler off by tapping “Boiler off”
The boiler follows the shutdown procedure and switches to "Boiler off“ mode
❒ Allow the boiler to cool for at least 1 hour
❒ Switch off the main switch and take precautions to prevent accidental
switching on
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.
2Safety
Residual risks
14 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

2.9 Emergency procedure
2.9.1 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
2.9.2 Smell of flue gas
DANGER
If you smell flue gas in the boiler room:
Inhaling toxic flue gas can be fatal!
If you smell flue gas in the room where the boiler is installed:
❒ Keep all the doors on the boiler closed
❒ Shut down the boiler according to procedure
❒ Ventilate the room where the boiler is installed
❒ Close the fire door and doors to living areas
Recommendation: Do not install smoke alarms and carbon monoxide detectors near
the system.
2.9.3 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 PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 15

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
16 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

▪ 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
TRVB H118 - Technical directives on fire protection/prevention
3.3 Room air-independent operation
The PE1 Pellet has a central air connection on the back of the boiler. If appropriate
supply air and flue gas connections are installed, the boiler can be classified according
to EN 15035 as a type C42 / type C82 or according to DIBt as a type FC42x / type FC52x.
The conditions for room air-independent operation of the boiler at the installation site
must be clarified with the local authority responsible (authority, chimney sweep, ...).
Definitions as per EN 15035
Boiler that is connected via its combustion air supply and flue gas outlet, with a
connecting piece that may be supplied, to a shared chimney with a shaft for
combustion air supply and a shaft for flue gas outlet. The mouths of the air and flue
gas chimney are either concentric or so close to each other that similar wind
conditions apply.
NOTICE! Air is supplied by an air and flue gas system!
A boiler that is connected via its combustion air supply and flue gas outlet, with a
connecting piece, to a wind protection device and a single or shared chimney.
NOTICE! Air supply via an air supply line that is independent from the chimney
system!
NOTICE! This design requires a wind protection device. If a protective grating is fitted,
you must ensure that the mesh size is sufficiently large to prevent a significant loss of
pressure and/or seal from dirt!
The second index "2" (C42 / C82) indicates type C boilers with a blower fan downstream
of the combustion chamber or the heat exchanger.
Note on standards
Type C4
Type C8
Notes for operating a heating system 3
General information for installation room (boiler room)
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 17

Definitions as per DIBt
One appliance with flue gas fan for connection to an air/flue system. The combustion
air line from the air shaft and the connecting piece to the chimney are part of the
appliance.
One appliance with flue gas fan for connection to a chimney. The combustion air line
from the air shaft and the connecting piece to the chimney are part of the appliance.
When dimensioning pipe bends in the supply air line you should note that:
The ratio of the radius of curvature (r) to pipe diameter (d) should be greater than 1
r:d ≥ 1
For example:
- Diameter of supply air connection = 60 mm
- Minimum radius of pipe bends = 60 mm
Install the supply air line in as straight a line as possible and over the shortest path.
Keep the number of pipe bends to a minimum.
In addition, the following applies: The maximum resistance of the supply air line is 20
Pa!
You can find the necessary dimensions of the supply air connections in the boiler in
the technical data sheets.
3.4 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
Type FC42x
Type FC52x
3Notes for operating a heating system
Requirements for central heating water
18 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com

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)
>50 ≤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
Notes for operating a heating system 3
Requirements for central heating water
Operating Instructions PE1 Pellet 7-35 / PE1 Pellet Unit 7-20 | B1001020_en 19

3.5 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.
Pump-controlled pressure maintenance
A pump-controlled pressure maintenance unit essentially consists of a pressure-
maintenance pump, relief valve and an unpressurised receiving tank. The valve
releases hot water into the receiving tank if the pressure is too high. If the pressure
drops below a preset value, the pump draws water from the receiving tank and feeds it
back into the heating system. Pump-controlled pressure maintenance systems with
open expansion tanks (e.g. without a diaphragm) introduce ambient oxygen via the
surface of the water, exposing the connected system components to the risk of
corrosion. These systems offer no oxygen removal for the purposes of corrosion
control as required by VDI 2035 and in the interests of corrosion protection should not
be used.
3Notes for operating a heating system
Notes for using pressure maintenance systems
20 Froling GesmbH | A-4710 Grieskirchen, Industriestraße 12 | www.froeling.com