Fröling Lambdamat LM 650 User manual

Operating instructions
Lambdamat LM 650 / 750 / 1500
Translation of original German version of operating instructions for operators.
Read and follow all instructions and safety instructions.
All errors and omissions excepted.
B1580122_en | Edition 19/08/2022

Table of contents
ii B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
1 General information .................................................................................................................................... 4
1.1 Lambdamat LM 1500 product overview ................................................................................................ 5
2 Safety............................................................................................................................................................ 6
2.1 Hazard levels of warnings ..................................................................................................................... 6
2.2 Pictograms used ................................................................................................................................... 7
2.3 General safety information .................................................................................................................... 8
2.4 Permitted uses ...................................................................................................................................... 9
2.4.1 Permitted fuels ........................................................................................................................... 9
2.4.2 Non-permitted fuels.................................................................................................................... 11
2.4.3 Qualification of operating staff ................................................................................................... 11
2.4.4 Protective equipment for operating staff .................................................................................... 11
2.5 Safety devices....................................................................................................................................... 12
2.5.1 External safety devices .............................................................................................................. 13
2.6 Residual risks........................................................................................................................................ 14
2.7 Emergency procedure........................................................................................................................... 15
2.7.1 Overheating of the system ......................................................................................................... 15
2.7.2 Smell of flue gas ........................................................................................................................ 15
2.7.3 Fire in the system....................................................................................................................... 15
3 Notes for operating a heating system ....................................................................................................... 16
3.1 Installation and approval ....................................................................................................................... 16
3.2 Installation site ...................................................................................................................................... 16
3.3 Combustion air supply at the installation room ..................................................................................... 17
3.4 Domestic hot water ............................................................................................................................... 18
3.5 Pressure maintenance systems ............................................................................................................ 19
3.6 Return lift............................................................................................................................................... 20
3.7 Storage tank.......................................................................................................................................... 20
3.8 Chimney connection/chimney system................................................................................................... 20
4 Operating the system.................................................................................................................................. 21
4.1 Assembly and initial startup .................................................................................................................. 21
4.2 Filling/refilling the store with fuel ........................................................................................................... 22
4.2.1 Loading of fuel for a partially emptied store with rotary agitator ................................................ 23
4.2.2 Loading fuel into an empty fuel store with a rotary agitator ....................................................... 23
4.2.3 Blowing in fuel for a partially emptied store with rotary agitator................................................. 24
4.2.4 Blowing in fuel for an empty store with rotary agitator ............................................................... 24
4.2.5 Blowing in pellets for a store with pellet screw........................................................................... 25
4.2.6 Loading fuel in a store space with a sliding floor discharge unit................................................ 26
4.2.7 Loading fuel in a store space with a horizontal screw discharge unit ........................................ 27
4.2.8 Loading fuel in a store space with an inclined screw discharge unit.......................................... 27
4.2.9 Drainage of fuel store................................................................................................................. 28
4.3 Heating up the boiler ............................................................................................................................. 29
4.3.1 Switching on the power supply .................................................................................................. 29
4.3.2 Switching on the boiler............................................................................................................... 29
4.3.3 Regulating the boiler .................................................................................................................. 29
4.3.4 Switching off the boiler............................................................................................................... 29
4.3.5 Switching off the power supply .................................................................................................. 30
5 Servicing the system .................................................................................................................................. 31
5.1 General information on servicing .......................................................................................................... 31
5.2 Required tools ....................................................................................................................................... 33
5.3 Inspection.............................................................................................................................................. 34
5.3.1 Checking the system pressure................................................................................................... 34

Table of contents
B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 iii
5.3.2 Checking the thermal discharge safety device .......................................................................... 34
5.3.3 Checking the safety valve .......................................................................................................... 34
5.3.4 Checking the geared motors...................................................................................................... 34
5.3.5 Checking the quick vent valve ................................................................................................... 34
5.3.6 Checking the draught controller flap .......................................................................................... 35
5.3.7 General weekly inspection ......................................................................................................... 35
5.4 Cleaning ................................................................................................................................................ 36
5.4.1 Ash container for combustion chamber (optional) ..................................................................... 36
5.4.2 Cleaning the combustion and burning chamber ........................................................................ 38
5.4.3 Emptying the multicyclone ash container................................................................................... 40
5.5 Maintenance tasks ................................................................................................................................ 41
5.5.1 Periodic inspection and cleaning ............................................................................................... 41
5.5.2 Periodic inspection and cleaning (approx. 1,000 hrs) ................................................................ 42
5.5.3 Periodic inspection and cleaning (approx. 3,000hrs) ................................................................ 46
5.6 Maintenance instructions for hydraulic system ..................................................................................... 53
5.7 Emissions measurement by chimney sweep or regulatory body .......................................................... 53
5.7.1 Switch on the system ................................................................................................................. 54
5.7.2 Start emissions measurement ................................................................................................... 55
5.8 Maintenance agreement / Customer service ........................................................................................ 55
5.9 Replacement parts ................................................................................................................................ 56
5.10 Disposal information.............................................................................................................................. 56
5.10.1 Disposal of the ash .................................................................................................................... 56
5.10.2 Disposal of system components ................................................................................................ 56
6 Troubleshooting .......................................................................................................................................... 57
6.1 General faults in the power supply........................................................................................................ 57
6.1.1 Behaviour of system after a power failure.................................................................................. 57
6.2 Excessive temperature.......................................................................................................................... 57
6.3 Faults with fault message...................................................................................................................... 58
6.3.1 Procedure for fault messages .................................................................................................... 58

1 | General information
4 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
1 General information
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 information | 1
B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 5
1.1 Lambdamat LM 1500 product overview
1 Control cabinet with integrated controller 15 Thermal discharge valve connection
2 Main switch: switches the power supply on and off
for the entire system
16 Boiler return connection
3 SPS 4000 control panel 17 Safety valve connection
4 Reversing chamber door 18 Boiler flow connection
5 Combustion chamber door 19 Flue gas recirculation (FGR) (optional)
6 Burning chamber door 20 Primary air servo-motor flue gas recirculation
(FGR)
7 Combustion air fan 21 Secondary air servo-motor flue gas recirculation
(FGR)
8 Ash container 300l (optional) 22 Compressed air tank of compressed air cleaner
(optional)
9 Drive for ash removal (optional) 23 Air distribution frame of compressed air cleaner
(optional)
10 Burning chamber overpressure monitor 24 Primary air actuator
11 Under-pressure controller 25 Secondary air servo-motor II
12 Secondary air servo-motor I 26 Tertiary air servo-motor
13 Automatic ignition 27 High-limit thermostat (STL)
14 Burning chamber temperature sensor 28 Cleaning door

2 | Safety
6 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
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.

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B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 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
Always wear protective gloves Wear hearing protection
Keep the doors closed Turn off the main switch
Unauthorised access prohibited No not walk on the surface
Warning - hot surface Warning - hazardous electrical
voltage
Warning - hazardous or irritant
materials
Warning - automatic boiler startup
Hand injury warning Warning of injury to fingers or
hands, automatic fan
Cutting injury warning Warning of injury to fingers or
hands, automatic screw

2 | Safety
8 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
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:
rObserve the instructions and information in the manuals
rObserve the details on procedures for operation, maintenance and cleaning, as well
as troubleshooting in the respective manuals.
rAny 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:
rInstructions 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:
rOptimum boiler performance can only be guaranteed if the flue gas system is
functioning correctly.

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B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 9
2.4 Permitted uses
The Froling Lambdamat is designed exclusively for heating domestic water. Only use
fuels specified in the "Permitted fuels" section.
Ü "Permitted fuels" [}9]
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 Permitted fuels
Wood chips
Description according to
EN ISO 17225-4
Description
M20 Water content max. 20%
M30 Water content max. 30%
M35 Water content max. 35%
M401) Water content max. 40%
M501) Water content max. 50%
P16S Main proportion (at least 60% mass portion): 3.15 – 16 mm, max.
length of 45 mm, previously referred to as fine wood chips G30
P31S Main proportion (at least 60% mass portion): 3.15 – 31.5 mm, max.
length of 150 mm, previously referred to as medium-sized wood
chips G50
from 400 kW: P45S Main proportion (at least 60% mass portion): 3.15-45 mm, max.
length of 200 mm, previously referred to as medium-sized wood
chips G50
from 400 kW: P632) Main proportion (at least 60% mass portion): 3.15–63 mm, max.
length 350 mm, previously referred to as coarse wood chips G100
1. partial load conditions only to a limited extent
2. for hydraulic feeders only
Note on standards EU: Fuel as per EN 17225 – Part 4: Wood chips class A1 / P16S-P45S
Additional for
Germany:
Fuel class 4 (§3 of the 1st Federal Emissions Protection Ordinance (BimSchV)
in the last amended version)

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10 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
Wood pellets
Wood pellets made from natural wood with a diameter of 6mm
Note on standards EU: Fuel acc. to EN ISO 17225 - Part 2: Wood pellets class A1 / D06
and/or: ENplus / DINplus certification scheme
General note:
Before refilling the store, check for pellet dust and clean if necessary.
Wood shavings
Wood shavings generally cause problems with combustion. Therefore their use is
permitted only with authorisation from Froling. The following additional points also apply:
▪ Sawdust and carpentry waste should only be used with systems with a rotary valve.
▪ The store should be fitted with a pressure release device in accordance with regional
regulations.
▪ The same limits apply for the permitted water content of sawdust as for wood chips.
NOTICE
For fuels with a water content < W30 the boiler's rated heat output can only be
guaranteed if it is used with a flue gas recirculation system (FGR).
Miscanthus
Switchgrass or elephant grass (Latin name: miscanthus) is a C4 plant. Standards and
regulations for burning these plants have not been standardised, so the following applies:
NOTICE!The regional regulations for burning miscanthus should be observed.
Operation may only be possible by special permit.
Changing the fuel
CAUTION
Incorrect fuel parameter settings:
Incorrect parameter settings have a significant adverse effect on the functioning of
the boiler, and as a result this will invalidate the guarantee.
Therefore:
rIf the fuel is changed (e.g. from wood chips to pellets), the system must be reset by
Froling customer services.

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B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 11
2.4.2 Non-permitted fuels
The use of fuels other than those defined in the "Permitted fuels" section, and particularly
the burning of refuse, is not permitted
NOTICE
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:
rUse only the permitted fuels
2.4.3 Qualification of operating staff
CAUTION
If unauthorised persons enter the Boiler room:
Risk of personal injury and damage to property
rThe 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.
2.4.4 Protective equipment for operating staff
You must ensure that staff have the protective equipment specified by accident
prevention regulations!
▪ During inspection and cleaning tasks wearing the following
equipment is mandatory:
- proper work clothing
- protective gloves
- sturdy shoes
▪ Additional equipment is mandatory during operation:
- hearing protection (sound level > 70 dB)
- protective goggles

2 | Safety
12 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
2.5 Safety devices
1 BOILER OFF (switches off the boiler to prevent overheating)
rTap “Boiler off”
ÄAutomatic mode is switched off
ÄControl system follows the boiler shutdown procedure
ÄThe pumps continue to run
NOTICE!Never use the main switch!
2 MAIN SWITCH (switches off the power supply)
Before carrying out work on the boiler:
rTap “Boiler off”
ÄAutomatic mode is switched off
ÄControl system follows the boiler shutdown procedure
rSwitch off the main switch and let the boiler cool down
3 SAFETY OVERLOAD SWITCHES, MOTOR PROTECTION SWITCHES, RESIDUAL
CURRENT PROTECTIVE DEVICES (RCD)
Switch off the related component in the event of fault currents or overloads.
4 SAFETY TEMPERATURE LIMITER (STL) (protection against overheating)
The STL switches off the combustion system when the boiler reaches 95 - 100°C. The
pumps continue to run. Once the temperature falls to below approx. 85°C, the STL can be
reset mechanically.
5 DOOR CONTACT SWITCH
When the door is opened, the induced draught is kept at a constant speed and the
combustion air and FGR blower fan stops.
TV THERMAL DISCHARGE VALVE (protection against overheating)

Safety | 2
B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 13
The thermal discharge valve opens at approx. 100°C and feeds cold water to the safety
heat exchanger to lower the boiler temperature
SAFETY VALVE (not shown, supplied by the customer)
When the boiler pressure reaches a maximum of 6 bar, the safety valve opens and the
heated water is blown off in the form of steam.
2.5.1 External safety devices
Hydraulic chamber safety switch
Before starting any maintenance work in the hydraulic chamber of the sliding floor:
rTurn the safety switch to the "0" position
ÄThe boiler follows the shutdown procedure and the discharge is deactivated
rTurning the selector switch past the "0" position engages the locking lever
ÄThe switch can be locked with a padlock to prevent it from being switched on again
On completion of the maintenance work:
rRemove the padlock
rTurn the selector switch past the "0" position to automatically release the locking
switch. The selector switch can now be turned back to the "1" position.
rAcknowledge the fault and press the Start button to activate the boiler
Guardrail
When working at a height, appropriate measures must be taken in accordance with the
applicable national industrial safety guidelines to protect against the risk of falling (e.g.
ladders, platforms, etc.). It is the responsibility of the operator to select and provide these
means.
Alternatively, a railing can be fitted to the top of the boiler as per EN ISO 14122.

2 | Safety
14 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
2.6 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:
rShut down the boiler according to procedure (“Switched off OFF” operating status)
and allow it to cool down
rProtective gloves must usually be worn for work on the boiler, and it should only be
operated using the handles provided
rInsulate the flue gas pipes and do not touch them during operation
WARNING
Opening the door to the combustion or burning chamber, or the cleaning door or lids
during operation
may result in injury or damage or flue gas generation!
Therefore:
rDo not open any doors or lids while the boiler is in operation!
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:
rOnly use fuels specified in the "Permitted fuels" section of these operating
instructions.
WARNING
Inspection and cleaning work on a system which is operational:
Risk of serious injuries from automatic startup of the system and severe burns
from hot parts and the flue gas pipe!
When working on the system:
ralways wear protective gloves
ronly operate the boiler using the handles provided
rswitch off the boiler by tapping “Boiler off” at the mode icon
ÄThe boiler follows the shutdown procedure and switches to “Switched off OFF“
status
rswitch off the main switch and take precautions to prevent accidental switching on
rallow the boiler to cool off for at least 1 hour
ronce all of the tasks have been completed, turn the main switch back on and switch
the boiler on in the desired mode

Safety | 2
B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 15
2.7 Emergency procedure
2.7.1 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.
rKeep all the doors on the boiler closed
rOpen all mixing valve taps, switch on all pumps.
ÄThe Froling heating circuit control takes on this function in automatic operation.
rLeave the boiler room and close the door
rIncrease heat consumption by turning on all radiators and other appliances
rOpen any thermostatic valves on the radiator and ensure sufficient heat dissipation
from the rooms
If the temperature does not drop:
rContact the installer or Froling customer services
2.7.2 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:
rKeep all the doors on the boiler closed
rShut down the boiler according to procedure
rVentilate the room where the boiler is installed
rClose the fire door and doors to living areas
Recommendation: Do not install smoke alarms and carbon monoxide detectors near the
system.
2.7.3 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:
rLeave the boiler room
rClose the doors
rInform the fire department

3 | Notes for operating a heating system
16 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
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
The boiler should be operated in a closed heating system. The following standards
govern the installation:
Note on standards EN 12828 - Heating Systems in Buildings
IMPORTANT: Every 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 Installation site
Requirements for the load bearing substrate:
▪ Flat, clean and dry
▪ Non-combustible and with sufficient load-bearing capacity
Conditions at the installation site:
▪ Frost-free
▪ Sufficiently well lit
▪ Free of explosive atmospheres such as flammable substances, hydrogen halides,
cleaning agents and consumables
▪ Installation at altitude higher than 2000 metres above sea level only after consultation
with the manufacturer
▪ The system must be protected against gnawing and nesting by animals (such as
rodents)
▪ No flammable materials in proximity to the system

Notes for operating a heating system | 3
B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 17
3.3 Combustion air supply at the installation room
The system is operated in open flue mode, i.e. the combustion air required to operate the
boiler is drawn from the installation room.
Requirements:
▪ Opening to the atmosphere
– Weather conditions must not affect the air flow in any way (e.g. snow and foliage)
– Cross-section area free of obstructions such as cover gratings and slats
▪ Air supply lines
– For air supply lines longer than 2 metres and where mechanical means are used
to feed combustion air, the flow rate must be calculated (maximum flow rate = 1 m/
s)
Note on standards ÖNORM H 5170 - Construction and fire protection requirements
TRVB H118 - Technical directives on fire protection/prevention

3 | Notes for operating a heating system
18 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
3.4 Domestic hot 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:
rAim 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 8.2 and 9.0
rUse prepared water which complies with the standards cited above for filling and
make-up water
rAvoid leaks and use a closed heating system to maintain water quality during
operation
rWhen filling with make-up water, always bleed the filling hose before connecting, in
order to prevent air from entering the system
rThe heating water must be clear and free from substances that lead to sediments.
rWith regard to corrosion protection, the use of fully demineralised filling and make-up
water with an electrical conductivity of up to 100 µS/cm is recommended in
accordance with EN 14868
Advantages of low-salt or fully demineralised 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
Filling and make-up water as well as heating water in accordance with VDI 2035:
Total heat output in kW Total earth alkalis in mol/m³ (total hardness in °dH)
Specific system volume in l/kW heat output1)
≤ 20 20 to ≤40 > 40
≤ 50
specific water content
heat generator ≥ 0.3 l/kW2)
none ≤ 3.0 (16.8) < 0.05 (0.3)
≤ 50
specific water content
heat generator < 0.3 l/kW2)
(e.g. circulation water heater) and
systems with electric heating
elements
≤ 3.0 (16.8) ≤ 1.5 (8.4)
> 50 to ≤ 200 ≤ 2.0 (11.2) ≤ 1.0 (5.6)
> 200 to ≤ 600 ≤ 1.5 (8.4) < 0.05 (0.3)
> 600 < 0.05 (0.3)
1. For calculating the specific system volume, the smallest individual heating capacity is to be used for systems with several heat generators.
2. In systems with several heat generators with different specific water contents, the smallest specific water content is decisive in each case.

Notes for operating a heating system | 3
B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500 19
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
3.5 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.

3 | Notes for operating a heating system
20 B1580122_en | Operating instructions Lambdamat LM 650 / 750 / 1500
3.6 Return lift
If the hot water return temperature is below the minimum return temperature, some of the
hot water outfeed will be mixed in.
NOTICE
Risk of dropping below dew point/condensation formation if operated without return
temperature control.
Condensation water forms an aggressive condensate when combined with
combustion residue, leading to damage to the boiler.
Take the following precautions:
rRegulations stipulate the use of a return temperature control.
ÄThe minimum return temperature is 60 °C. We recommend fitting some kind of
control device (e.g. thermometer).
3.7 Storage tank
NOTICE
In principle it is not necessary to use a storage tank for the system to run smoothly.
However we recommend that you use the system with a storage tank, as this ensures a
continuous supply of fuel in the ideal output range of the boiler.
For the correct dimensions of the storage tank and the line insulation (in accordance with
ÖNORM M 7510 or guideline UZ37) please consult your installer or Fröling.
Additional requirements for Switzerland in accordance with LRV Appendix 3, section 523
Automatic boilers with a rated thermal output ≤ 500 kW must be equipped with a heat
accumulator of a volume of at least 25 litres per kW rated thermal output.
3.8 Chimney connection/chimney system
EN 303-5 specifies that the entire flue gas system must be designed to prevent, wherever
possible, damage caused by seepage, insufficient feed pressure and condensation.
Please note in this respect that flue gas temperatures lower than 160K above room
temperature can occur in the permitted operating range of the boiler.
NOTICE!Please see the technical data contained in the assembly instructions for
further information about standards and regulations as well as the flue gas
temperatures when clean and the other flue gas values!