REMEHA Calenta 25s Manual

Netherlands
EN
High-efficiency wall-hung condensing gas boilers
Calenta 25s - 28c - 35s - 40c
Installation and
Service Manual
7600585-01

EG declaration of conformity
The device complies with the standard type described in the EG
declaration of conformity. It was manufactured and commissioned in
accordance with European directives.
The original of the declaration of compliance is available from the
manufacturer.

Contents
1 Introduction ................................................................................................6
1.1 Symbols used .......................................................6
1.2 Abbreviations ........................................................6
1.3 General ..................................................................6
1.3.1 Manufacturer's liability .............................................6
1.3.2 Installer's liability .....................................................7
1.4 Homologations ......................................................7
1.4.1 Certifications ...........................................................7
1.4.2 Equipment categories .............................................9
1.4.3 Additional Directives ................................................9
1.4.4 Factory test .............................................................9
2Safety instructions and recommendations ............................................10
2.1 Safety instructions .............................................10
2.2 Recommendations ..............................................10
3 Technical description ..............................................................................12
3.1 General description ............................................12
3.2 Main parts ............................................................12
3.3 Operating principle .............................................13
3.3.1 Gas/air setting .......................................................13
3.3.2 Combustion ...........................................................14
3.3.3 Heating and domestic hot water production ..........14
3.3.4 Control system ......................................................14
3.3.5 Adjustment ............................................................14
3.3.6 Regulation of the water temperature .....................15
3.3.7 Protection against a shortage of water ..................15
3.3.8 Maximum temperature protection .........................15
3.3.9 Skeleton Diagrams ................................................16
3.3.10 Shunt pump ...........................................................16
3.3.11 Water flow rate ......................................................17
3.4 Technical specifications ....................................17
4 Installation ................................................................................................20
4.1 Regulations governing installation ...................20
4.2 Package list .........................................................20
4.2.1 Standard delivery ..................................................20
4.2.2 Accessories ...........................................................21
040412 - 7600585-01 1

4.3 Choice of the location ........................................22
4.3.1 Data plate ..............................................................22
4.3.2 Location of the boiler .............................................22
4.3.3 Ventilation .............................................................23
4.3.4 Main dimensions ...................................................24
4.4 Positioning the boiler .........................................25
4.5 Alternatives for hydraulic connections ............26
4.5.1 Connection of the underfloor heating ....................26
4.5.2 Connection of a solar hot water tank .....................26
4.5.3 Connection of an independent hot water
tank .......................................................................27
4.5.4 Geyser use ............................................................28
4.5.5 Solo use ................................................................29
4.6 Hydraulic connections .......................................29
4.6.1 Flushing the system ..............................................29
4.6.2 Connection of the heating circuit ...........................30
4.6.3 Hydraulic connection of the water circuit for domestic
use ........................................................................31
4.6.4 Connecting the expansion vessel .........................31
4.6.5 Connecting the condensate discharge pipe ..........31
4.7 Gas connection ...................................................32
4.8 Connections for the air and exhaust
pipes ....................................................................32
4.8.1 Classification .........................................................32
4.8.2 Outlets ...................................................................33
4.8.3 Lengths of the air/flue gas pipes ...........................34
4.8.4 Specific air/flue gas applications ...........................36
4.8.5 Additional Directives ..............................................36
4.8.6 Air/Exhaust adapter ...............................................37
4.8.7 Connection of the combustion gas exhaust
pipe .......................................................................38
4.8.8 Connection of the air intake pipe ...........................38
4.9 Electrical connections ........................................39
4.9.1 Control unit ............................................................39
4.9.2 Recommendations ................................................40
4.9.3 Standard control PCB ...........................................41
4.9.4 Connecting the room thermostat ...........................42
4.9.5 Connecting the outside temperature sensor ........43
4.9.6 Connect frost protection ........................................43
4.9.7 Connecting the calorifier sensor/thermostat .........44
4.9.8 PC/Laptop connection ...........................................45
4.9.9 Shutdown input .....................................................45
4.9.10 Release input ........................................................45
4.10 Optional electrical connections ........................46
4.10.1 Connection options for the 0-10 V control PCB
(IF-01) ...................................................................46
4.10.2 Connection possibilities for the PCB (SCU-
S02) .......................................................................47
Contents
040412 - 7600585-01 2

4.11 Electrical diagram ...............................................50
4.12 Filling the system ...............................................51
4.12.1 Water treatment ....................................................51
4.12.2 Filling the siphon ...................................................51
4.12.3 Filling the system ..................................................52
5 Commissioning ........................................................................................53
5.1 Control panel .......................................................53
5.1.1 Functions of the keys ............................................53
5.1.2 Meaning of the symbols on the display .................53
5.2 Check points before commissioning ................54
5.2.1 Preparing the boiler for commissioning .................54
5.2.2 Gas circuit .............................................................55
5.2.3 Hydraulic circuit .....................................................55
5.2.4 Electrical connections ...........................................55
5.3 Commissioning the boiler ..................................55
5.4 Gas settings ........................................................57
5.4.1 Adapting to another gas type ................................57
5.4.2 Setting the air/gas ratio (Full load) ........................57
5.4.3 Setting the air/gas ratio (Part load) ......................59
5.4.4 Basic setting for the gas/air ratio ...........................60
5.5 Checks and adjustments after
commissioning ...................................................60
5.5.1 Finalizing work ......................................................60
5.6 Reading out measured values ...........................61
5.6.1 Reading the various current values .......................61
5.6.2 Readout from the hour counter and percentage of
successful starts ....................................................62
5.6.3 Status and sub-status ...........................................63
5.7 Changing the settings ........................................64
5.7.1 Parameter descriptions .........................................64
5.7.2 Modification of the user-level parameters .............66
5.7.3 Modification of the installer-level parameters ........67
5.7.4 Setting the maximum heat input for central heating
operation ...............................................................68
5.7.5 Return to the factory settings ................................69
5.7.6 Carrying out an auto-detect ...................................70
5.7.7 Setting the manual mode ......................................70
5.7.8 Setting the legionella protection function ..............70
040412 - 7600585-01 3

6 Switching off the boiler ............................................................................71
6.1 Installation shutdown .........................................71
6.2 Frost protection ..................................................71
6.3 Switching off the central heating ......................72
6.4 Shutting down domestic hot water
production ...........................................................72
7 Checking and maintenance .....................................................................73
7.1 Maintenance message ........................................73
7.2 Preventive maintenance with automated service
message ..............................................................73
7.2.1 Resetting the automatic maintenance
message ................................................................74
7.2.2 Dealing with the next maintenance message and
starting the new maintenance period ....................74
7.3 Standard inspection and maintenance
operations ...........................................................75
7.3.1 Checking the hydraulic pressure ...........................75
7.3.2 Checking the ionization current .............................75
7.3.3 Checking the transfer capacity ..............................75
7.3.4 Checking the tightness of the flue gas evacuation and
air inlet connections ..............................................76
7.3.5 Checking combustion ............................................76
7.3.6 Checking the automatic air vent ............................77
7.3.7 Checking the safety valve .....................................77
7.3.8 Checking the siphon ..............................................77
7.3.9 Checking the burner and cleaning the heat
exchanger .............................................................78
7.4 Specific maintenance operations ......................79
7.4.1 Replacing the ionization/ignition electrode ............79
7.4.2 Cleaning the plate exchanger (domestic hot water
end) and the water filter cartridge .........................79
7.4.3 Replacing the 3-way valve ....................................82
7.4.4 Replacing the non-return valve .............................83
7.4.5 Assembling the boiler ............................................84
8 Troubleshooting .......................................................................................85
8.1 Error codes ..........................................................85
8.2 Shutdowns and lock-outs ..................................88
8.2.1 Blockage ...............................................................88
8.2.2 Blocking .................................................................88
8.3 Error memory ......................................................90
8.3.1 Error readout memorised ......................................91
8.3.2 Deletion of the error display ..................................92
Contents
040412 - 7600585-01 4

9 Spare parts ................................................................................................93
9.1 General ................................................................93
9.2 Spare parts ..........................................................93
040412 - 7600585-01 5

1 Introduction
1.1 Symbols used
In these instructions, various danger levels are employed to draw the
user's attention to particular information. In so doing, we wish to
safeguard the user's safety, obviate hazards and guarantee correct
operation of the appliance.
DANGER
Risk of a dangerous situation causing serious physical
injury.
WARNING
Risk of a dangerous situation causing slight physical
injury.
CAUTION
Risk of material damage.
Signals important information.
¼ Signals a referral to other instructions or other pages in the
instructions.
1.2 Abbreviations
43CE: Collective conduit for sealed boiler
4Central heating: Central heating
4COP: Energy performance
4DHW: Domestic hot water
4HRU: Heat Recovery Unit
1.3 General
1.3.1. Manufacturer's liability
Our products are manufactured in compliance with the requirements
of the various applicable European Directives. They are therefore
delivered with [ marking and all relevant documentation.
1. Introduction Calenta 25s - 28c - 35s - 40c
6040412 - 7600585-01

In the interest of customers, we are continuously endeavouring to
make improvements in product quality. All the specifications stated in
this document are therefore subject to change without notice.
Our liability as the manufacturer may not be invoked in the following
cases:
4Failure to abide by the instructions on using the appliance.
4Faulty or insufficient maintenance of the appliance.
4Failure to abide by the instructions on installing the appliance.
1.3.2. Installer's liability
The installer is responsible for the installation and inital start up of the
appliance. The installer must respect the following instructions:
4Read and follow the instructions given in the manuals provided
with the appliance.
4Carry out installation in compliance with the prevailing legislation
and standards.
4Perform the initial start up and carry out any checks necessary.
4Explain the installation to the user.
4If a maintenance is necessary, warn the user of the obligation to
check the appliance and maintain it in good working order.
4Give all the instruction manuals to the user.
1.4 Homologations
1.4.1. Certifications
CE identification no PIN 0063BT3444
NOx classification 5 (EN 297 pr A3, EN 656)
Type of connection
(Flue gas outlet)
B23 , B23P , B33 , C13 , C33 , C43 , C53 , C63 , C83 ,
C93
Depending on the type of appliance and the gross heat
requirements for domestic water in accordance with NEN
5128, efficiency values up to 0,825 can be applied to
determine EPC.
nApproval labels for gas
The boiler has been given several approval labels for gas. Stichting
Energie Prestatiekeur grants these independent labels on
performance to gas consumption appliances that meet specific
provisions on a certain number of aspects (efficiency, environmental
friendliness, comfort). The labels have the following meaning:
Calenta 25s - 28c - 35s - 40c 1. Introduction
040412 - 7600585-01 7

The labels are not guaranteed if the boiler is adapted to
G20 or G31.
HR 107 gas approval (High efficiency heating)
This means that the efficiency of the boiler when producing heating
water is 107% higher than the Gaskeur HR criterion in relation to
Hi. This means that the boiler is economical and therefore less costly
and more environmentally friendly.
HRww gas approval (High efficiency hot water)
This implies that the hot water/heating boiler produces hot water
economically and efficiently, without wasting energy or water
therefore.
CW 4 gas approval (Hot water comfort)
This means that, for the preparation of hot water, the Calenta 28c
satisfies application class 4. With the application of class 4, the
Calenta 28c is appropriate for:
4A draw-off flow rate of at least 7,5 l/min at 60°C.
4A shower function from 6 l/min up to at least 12,5 l/min at 40°C.
4Filling a bathtub in less than 11 minutes with 120 litres of water at
40°C on average.
The simultaneity of these functions is not a requirement.
Parameters for which the performance of the Calenta 28c boiler
complies with the Hot Water Comfort classification:
4Rotation speed on start-up 3000 rpm.
4Maximum DHW rate 6200 rpm.
4Energy-saving mode: Stop.
CW 5 gas approval (Hot water comfort)
This means that, for the preparation of hot water, the Calenta 40c
satisfies application class 5. With the application of class 5, the
Calenta 40c is appropriate for:
4Hot water comfort.
4A shower function from 6 l/min up to at least 12,5 l/min at 40°C.
4Filling a bathtub in less than 10 minutes with 150 litres of water at
40 °C on average.
The simultaneity of these functions is not a requirement.
Parameters for which the performance of the Calenta 40c boiler
complies with the Hot Water Comfort classification:
4Rotation speed on start-up 4000 rpm.
4Maximum DHW rate 6800 rpm.
4Energy-saving mode: Stop.
SV gas approval (Clean combustion)
T001057-A
T001058-A
T001055-A
T001795-A
T001059-A
1. Introduction Calenta 25s - 28c - 35s - 40c
8040412 - 7600585-01

This means that the boiler complies with the NOx Order and
provisions on clean combustion. The boiler has a gas/air coupling
combined with a fully premixed burner. For this reason, the emission
of NOx and CO is as low as possible.
NZ gas approval (Solar water heater reheating)
This implies that the hot water/heating boiler can operate on reheating
for solar water heaters. The label (solar water heater reheating) is
valid in combination with the connection kit for solar water heaters.
Owing to the possible formation of legionella, the boiler must not be
shut down or the DHW temperature set below 60°C.
1.4.2. Equipment categories
Gas category Gas type Connection pressure (mbar)
II2L3P , I2H G20 (Gas H) 20
G25 (Gas L) 25
G31 (Propane) 30/50
The boiler is preset in the factory to operate on natural gas G25 (Gas
L).
1.4.3. Additional Directives
Apart from the legal provisions and Directives, the additional
Directives described in these instructions must also be observed.
For all provisions and Directives referred to in these instructions, it is
agreed that all addenda or subsequent provisions will apply at the
time of installation.
1.4.4. Factory test
Before leaving the factory, each boiler is set for optimum performance
and tested to check the following items:
4Electrical safety
4Adjustment (CO2)
4Domestic hot water mode (Only on models with domestic hot water
production)
4Water tightness
4Gas tightness
4Parameter settings
T001779-B
NZ
Calenta 25s - 28c - 35s - 40c 1. Introduction
040412 - 7600585-01 9

2 Safety instructions and
recommendations
2.1 Safety instructions
DANGER
If you smell gas:
1. Do not use a naked flame, do not smoke, do not
operate electrical contacts or switches ( doorbell,
light, motor, lift, etc..).
2. Shut off the gas supply.
3. Open the windows.
4. Trace possible leaks and seal them immediately.
5. If the gas leak is before the gas meter, contact the
gas supplier.
DANGER
If you smell flue gases:
1. Switch the appliance off.
2. Open the windows.
3. Trace possible leaks and seal them immediately.
2.2 Recommendations
WARNING
4Installation and maintenance of the boiler must be
carried out by a qualified professional in compliance
with prevailing local and national regulations.
4When working on the boiler, always disconnect the
boiler from the mains and close the main gas inlet
valve.
4After maintenance or repair work, check all
installations to ensure that there are no leaks.
CAUTION
The boiler must be installed in a frost-free environment.
Keep this document close to the place where the boiler is
installed.
Casing components
2. Safety instructions and recommendations Calenta 25s - 28c - 35s - 40c
10 040412 - 7600585-01

Only remove the casing for maintenance and repair operations. Put
the casing back in place after maintenance and repair operations.
Instructions stickers
The instructions and warnings affixed to the appliance must never be
removed or covered and must remain legible during the entire lifespan
of the appliance. Immediately replace damaged or illegible
instructions and warning stickers.
Modifications
Modifications may only be made to the boiler after the written
permission of Remeha to do so.
Calenta 25s - 28c - 35s - 40c 2. Safety instructions and recommendations
040412 - 7600585-01 11

3 Technical description
3.1 General description
High-efficiency wall-hung condensing gas boilers
4High efficiency heating.
4Low pollutant emissions.
Boiler type:
4Calenta 25s - 35s: Heating only (Production of domestic hot water
can be ensured by a separate hot water calorifier).
4Calenta 28c - 40c: Heating and domestic hot water production.
3.2 Main parts
Calenta 25s - 28c
1Flue gas outlet
2Casing/air box
3Outlet for measuring combustion gases
4Mixer pipe
5Heating flow hose
6Air intake silencer
7Box for the control PCBs (accessory)
8Combined venturi and gas valve unit
9Flow end hydroblock
10 Safety valve outlet pipe
11 Siphon
12 Instrument box
13 Shunt pump
14 Return end hydroblock
15 Plate heat exchanger (DHW) (Only on models with
domestic hot water production)
16 3-way valve (Only on models with domestic hot water
production)
17 Condensate receiver tank
18 Fan
19 Heat exchanger (Central heating)
20 Ignition/ionization electrode
21 Air intake
T000822-BT000822-D
9
8
7
6
4
5
2
3
10
12
14
13
16
17
19
20
18
15
1 21
11
3. Technical description Calenta 25s - 28c - 35s - 40c
12 040412 - 7600585-01

Calenta 35s - 40c
1Flue gas outlet
2Casing/air box
3Outlet for measuring combustion gases
4Mixer pipe
5Heating flow hose
6Air intake silencer
7Box for the control PCBs (accessory)
8Combined venturi and gas valve unit
9Flow end hydroblock
10 Safety valve outlet pipe
11 Siphon
12 Instrument box
13 Shunt pump
14 Return end hydroblock
15 Plate heat exchanger (DHW) (Only on models with
domestic hot water production)
16 3-way valve (Only on models with domestic hot water
production)
17 Condensate receiver tank
18 Fan
19 Heat exchanger (Central heating)
20 Ignition/ionization electrode
21 Air intake
3.3 Operating principle
3.3.1. Gas/air setting
The casing fitted to the boiler is also used as an air box. Air is sucked
in by the fan and gas injected into the venturi by the fan intake. The
fan rotation speed is set according to the settings parameters, the
thermal energy requirement and the temperatures measured by the
temperature sensors. The gas and air are mixed in the venturi. The
gas/air ratio ensures that the quantities of gas and air are adjusted to
each other. This provides optimum combustion on the entire output
range. The gas/air mixture is fed into the burner on top of the
exchanger.
T002886-C
2
14
16
15
13
17
18
19
20
3
4
5
6
7
8
9
10
11
12
1 21
Calenta 25s - 28c - 35s - 40c 3. Technical description
040412 - 7600585-01 13

3.3.2. Combustion
The burner heats the heating water circulating in the heat
exchanger. At a return temperature lower than around 55°C, the flue
gases cool down to a temperature lower than the dew point, thus
causing the condensation of the water vapour contained in the flue
gases in the back side of the heat exchanger. The heat released
during this condensation process (the latent heat or condensing heat)
is also transferred to the heating water. The cooled combustion gases
are evacuated via the combustion gas outlet flue. The condensation
water is evacuated via a siphon.
3.3.3. Heating and domestic hot water production
On heating and domestic hot water production type boilers, an
integrated plate exchanger heats the domestic water. A 3-way valve
determines whether the heated water is fed into the heating system
or the plate exchanger. A pick-up sensor signals that a hot water tap
is being opened. This signal is transmitted to the control panel, which
then switches the 3-way valve to the hot water position and trips the
heating pump. The 3-way valve is spring-loaded but only consumes
electricity when it switches to another position.
The heating water reheats the domestic water in the plate
exchanger. In comfort mode, if there is no hot water draw-off, the
boiler handles the periodic reheating of the plate exchanger. Any
limescale particles are kept out of the plate exchanger by a self-
cleaning water filter (self-cleans once every 76 hours).
3.3.4. Control system
The boiler command, called Comfort Master©, handles a reliable
heat supply. This means that the boiler treats external negative
influences in a practical manner (notably when the water-flow is
insufficient or there are problems with air supply). In the presence of
such influences, the boiler doesn't switch into locking mode, but first
reduces his power and, depending on the nature of the
circumstances, will be temporarily out of service (blocking or stop).
The boiler will continue to supply heat as long as the situation does
not become dangerous.
3.3.5. Adjustment
The power of the boiler can be adjusted in the following ways:
4On/Off setting
The output between the minimum and maximum values varies
based on the heating flow set point temperature.
4Adjustable control
The output between the minimum and maximum values varies
based on the heating flow temperature determined by the
modulating control system.
4Analogue setting (0-10 V)
3. Technical description Calenta 25s - 28c - 35s - 40c
14 040412 - 7600585-01

1Celcia 10
2qSense
3iSense
It is possible to connect a 2-wire on/off thermostat to the boiler such
as the Celcia 10 or a power stealing thermostat. The boiler output
can be modulated by an OpenTherm system with an appropriate
modulating thermostat such as the qSense or the iSense.
3.3.6. Regulation of the water temperature
The boiler is fitted with an electronic temperature regulator having an
outlet and return temperature probe. The flow temperature can be set
between 20°C and 90°C. The boiler reduces its power when the set
outlet-temperature is attained. The cutout temperature is the set
heating outlet-temperature + 5 °C.
3.3.7. Protection against a shortage of water
The boiler is fitted with a safety device to prevent the shortage of water
based on temperature measurements. By reducing its output when
the water flow rate is in danger of becoming insufficient, the boiler
continues to operate as long as possible. If the flow rate is too weak
ΔT ≥ 50°C or the heating flow temperature increases too much, the
boiler is locked for 10 minutes, code 5t[09. When there is no
water in the boiler or the pump is not running, the boiler goes into
safety shutdown, code e[10 at ΔT ≥ 70°C.
3.3.8. Maximum temperature protection
The overheating safety device locks the boiler when the water
temperature is too high (110°C), code e[12.
¼ For more detailed information, see chapter: "Error codes",
page 85
T003757-A
1 2 3
Calenta 25s - 28c - 35s - 40c 3. Technical description
040412 - 7600585-01 15

3.3.9. Skeleton Diagrams
Calenta 25s - 35s
1Heat exchanger (Central heating)
2Heating flow
3Heating return
4Shunt pump (Central heating)
Calenta 28c - 40c
1Heat exchanger (Central heating)
2Hydroblock
3Plate heat exchanger (DHW)
4Heating flow
5Domestic hot water outlet
6Domestic cold water inlet
7Heating return
83-way valve
9Shunt pump (Central heating)
3.3.10. Shunt pump
The boiler is equipped with a circulating pump. This energy-efficient,
modulating circulating pump is controlled by the control unit based on
ΔT. The graph shows the manometric height at various outputs.
Calenta 25s - 28c
HManometric height central heating circuit
QWater flow
R000124-A
1
4
2 3
T001874-A
1
2
3
9
8
4 5 6 7
T002537-B
0 200 400 600 800 1000 1200
Q (l/h)
10 kW
15 kW
20 kW
25 kW
615
545
435
295
437 623 830 1037
0
100
200
300
400
500
700
H(mbar)
600
3. Technical description Calenta 25s - 28c - 35s - 40c
16 040412 - 7600585-01

Calenta 35s - 40c
HManometric height central heating circuit
QWater flow
Parameters p"8 and p"9 are used to modify the pump settings:
4If there are audible flowing noises in the system, the maximum
pump speed must be lowered using parameter p"9 (First of all,
vent the heating system).
4If there is insufficient flow in the radiators or if they do not warm
up completely, the minimum pump speed can be increased using
parameter p"8.
¼ See chapter: "Modification of the installer-level parameters",
page 67.
3.3.11. Water flow rate
The boiler's modulating control system limits the maximum difference
in temperature between the heating flow and return and the maximum
speed at which the flow temperature increases. In this way, the boiler
does not require a minimum water flow rate.
¼ If using thermostatic valves, see chapter: "Hydraulic
connections", page 29.
Calenta 25s
Δp Pressure drop
QWater flow (max = 1680 l/h)
Calenta 35s
Δp Pressure drop
QWater flow (max = 2460 l/h)
3.4 Technical specifications
T001748-B
0 250 500 750 1000 1250
0
100
200
300
400
500
700
800
H (mbar)
Q (l/h)
600
20 kW
25 kW
30 kW
35 kW
835 12521038
1465
606
418
530
291
T001978-A
0
100
200
300
400
500
600
700
0500 1037437 15001000 2000 2500
∆p [mbar]
Q [l/h]
623 830
∆T = 20K
10 kW
15 kW
20 kW
25 kW
T001749-B
0
100
200
300
400
500
600
0500 1043 1252 1465835 15001000 2000 2500
∆p [mbar]
Q [l/h]
∆T = 20K
20 kW
25 kW
30 kW
35 kW
Calenta 25s - 28c - 35s - 40c 3. Technical description
040412 - 7600585-01 17

Boiler type Calenta 25s 28c 35s 40c
General
EC indentification no. PIN 0063BT3444
Flow rate setting Adjustable Modulating, Start/Stop, 0 - 10 V
Nominal output (Pn)
Heating System (80/60 °C)
minimum-
maximum
kW 5,0 - 24,1 5,0 - 24,1 6,3 - 34,0 6,3 - 34,0
Factory setting kW 24,1 19,4 34,0 23,3
Nominal output (Pn)
Heating System (50/30 °C)
minimum-
maximum
kW 5,6 - 25,5 5,6 - 25,5 7,0 - 35,9 7,0 - 35,9
Factory setting kW 25,5 20,5 35,9 24,5
Nominal output (Pn)
DHW System
minimum-
maximum
kW - 5,0 - 28,6 - 6,3 - 39,7
Factory setting kW - 28,6 - 39,7
Nominal input (Qn)
Heating System (Hi)
minimum-
maximum
kW 5,2 - 25,0 5,2 - 25,0 6,5 - 35,1 6,5 - 35,1
Factory setting kW 25,0 20,1 35,1 24,0
Nominal input(Qn)
Heating System (Hs)
minimum-
maximum
kW 5,8 - 27,8 5,8 - 27,8 7,2 - 39,0 7,2 - 39,0
Factory setting kW 27,8 22,3 39,0 26,7
Nominal input (Qnw)
DHW System (Hi)
minimum-
maximum
kW - 5,2 - 28,0 - 6,5 - 38,8
Factory setting kW - 28,0 - 38,8
Nominal input (Qnw)
DHW System (Hs)
minimum-
maximum
kW - 5,8 - 31,1 - 7,2 - 43,1
Factory setting kW - 31,1 - 43,1
Heating efficiency under full
load (Hi) (80/60 °C) - % 96,3 96,3 96,9 96,9
Heating efficiency under full
load (Hi) (50/30 °C) - % 102,0 102,0 102,2 102,2
Heating efficiency under
partial load (Hi) (Return
temperature 60°C)
- % 96,1 96,1 96,3 96,3
Heating efficiency under
partial load (EN 92/42)
(Return temperature 30°C)
- % 108,0 108,0 108,2 108,2
Data on the gases and combustion gases
Gas categories - I2L3P and I2H
Gas inlet pressure G20 (Gas
H)
minimum-
maximum
mbar 17 - 30
Gas inlet pressure G25 (Gas
L)
minimum-
maximum
mbar 20 - 30
Gas inlet pressure G31
(Propane)
minimum-
maximum
mbar 30 - 50
Gas consumption G20 (Gas
H)
minimum-
maximum
m3/h 0,55 - 2,65 0,55 - 2,96 0,69 - 3,71 0,69 - 4,11
Gas consumption G25 (Gas
L)
minimum-
maximum
m3/h 0,64 - 3,08 0,64 - 3,45 0,80 - 4,32 0,80 - 4,78
Gas consumption G31
(Propane)
minimum-
maximum
m3/h 0,21 - 1,02 0,21 - 1,15 0,27 - 1,44 0,27 - 1,59
NOx-Emission per year (n =1) mg/kWh 38 38 42 42
Mass flue gas flow rate minimum-
maximum
kg/h 8,9 - 42,1 8,9 - 47,1 11,1 - 57,3 11,1 - 63,9
(1) Time needed as of the start of water draw-off to obtain an increase in temperature of 40K at the appliance's water outlet for the purposes of
installation calculation, based on the draw-off flow rate CW.
(2) The specific length of the pipe Ø 10/12 mm is the maximum uninsulated length, on the understanding that, in the most unfavourable summer
situation, the appliance will supply hot water in less than 30 s with a permanent increase in temperature of 35 ºC at the draw-off point in the
kitchen.
(3) Front panel removed
3. Technical description Calenta 25s - 28c - 35s - 40c
18 040412 - 7600585-01