RVR Energy Technology CAHA Midi 340 Quick start guide

CAHA Midi
Installation, Usage and Maintenance Instructions
20180713
Floor standing multi-sectional gas boilers
Models 340, 425, 510 and 600

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CAHA Midi Installation, Usage and Maintenance Instructions
INSTRUCTIONS FOR THE USER
If you have questions concerning the use of your boiler or heating system, please ask your installer. It is in your own inter-
est and that of the installer that you are aware of how to operate your boiler and heating system safely and efciently.
The appliance is not to be used by children or persons with reduced physical, sensory or mental capabilities,
or lack of experience and knowledge. Children, even if being supervised, must not play with the appliance.
In the case of failure or malfunction of the appliance, do not attempt to repair it yourself. Please contact your
installer. Repairs must only be carried out by qualied technicians. Failure to comply with these requirements can com-
promise the safety of the appliance.
OPERATION
Water, coming from the radiators or from the DHW unit is heated in the aluminium heat exchanger. The CH or DHW pump
guarantees circulation of water. The air needed for combustion is sucked in by a rpm controlled fan. At low boiler tempera-
tures the flue gases can be cooled down sufciently for condensation of the water. This water is drained to the sewer via a
built in syphon. This drainage must never be blocked. A burner controller with built in micro processor provides the electri-
cal control of the boiler.
TOPPING UP
The built in manometer indicates if the waterpressure is sufcient. As soon as the water pressure drops below 1 bar top-
ping up is necessary. If topping up becomes a regular occurrance, your installation should be checked by an installer.
Disconnect from the main. Connect the lling hose to the cold water tap and to the ll and drain valve of the boiler. Before
tightning the coupling in the installation slowly ll the hose with water allowing present air to escape. Now open the ll and
drain valve and slowly ll the installation until a pressure between 1.5 and 2.0 bar is reached. When nished connect again
to the main.
BLEEDING
To remove any air present in the heating system and boiler, bleeding is necessary. Disconnect from the main. Open all the
radiator valves. Bleed the air from all the radiators starting with the ones at the lowest point in the system. After bleeding,
check the water pressure and top-up if required (if water pressure has dropped below 1 bar). Connect to the main again.
Thank you for selecting a CAHA Midi Boiler. This product is the result of extensive research and experience in heating
system design.
This manual is an integral part of the product and should be retained. Please read it carefully, as it provides
important information regarding the installation and maintenance of the product.
The product should only be installed and maintained by a person qualied in the design and installation of heat-
ing systems. Failure to properly install or maintain the CAHA Midi may lead to injury, death or property damage.
WARNING
Carefully read the instructions contained in the manual as they provide important information regarding safe
installation and maintenance. The installation and maintenance must be performed in accordance with current
standards and according to the manufacturer’s instructions.
In the case of failure or malfunction of the appliance, do not attempt to repair it yourself. Please contact RVR Energy Tech-
nology Ltd by email at [e-mail].
Repairs must be only be carried out by a qualied technicians. Failure to comply with these requirements can compro-
mise the safety of the device.

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CAHA Midi Installation, Usage and Maintenance Instructions
STARTING THE BOILER
Please ask your installer how to start the boiler. Depending on how your heating system is controlled, this could be via an
external timeclock, thermostat, switch or otherwise. Once the boiler volt-free enable contacts are closed, the boiler will
commence its starting sequence.
BOILER FLOW TEMPERATURE
The burner controller can adjust the flow temperature between 20 ° and 85 °C. The temperature setting can be changed
using the control panel. The installation manual provides the instructions for setting the flow temperature.
DHW (HOT WATER) TEMPERATURE
From the factory, the DHW temperature is set to a value of 60 °C. This set value can be changed to any value between 35
and 65 °C using the buttons on the control panel. If the DHW device has a thermostat the DHW temperature can be adjust-
ed by setting this thermostat.
SWITCHING OFF THE BOILER
During summer time the room thermostat can be set to a lower value to turn off the boiler. During winter or
during a longer period of absence this temperature never should be set to a lower value than 15 °C. Don’t
switch off the power. During a period of frost all the radiators should be partly or totally opened to avoid danger
of freezing.
The integrated pump control will activate the pump every 24 hours for a short period even if no demand is present. This
prevents the pump jamming.
Only when work on the boiler is being carried out may the main electricity supply and gas supply be turned off (your install-
er can show where these are located).
ERRORS
If an error occurs rst check the following:
▪Is the room thermostat properly set?
▪Is the boiler connected to the main? Power supply present?
▪Is the gas valve opened?
▪Are the radiator valves open?
▪Is the water pressure in the installation higher than 1 bar?
▪Is the installation bled thoroughly?
An error is indicated by a code on the display. It is very important for the sake of a correct diagnosis to mention this code
when calling your installer. Reset the burner controller by pressing the ok button on the control panel. If the error occurs
frequently contact your installer.
MAINTENANCE
A yearly inspection of the boiler must be done by your installer. The lifespan and the reliability of the installation are im-
proved by doing so.The casing of the boiler may be cleaned with a soft cloth (no abrasives). Never use solvents like thinner!
CAUTION
The air supply (for air needed for combustion) and the flue parts are essential parts for safe and efcient oper-
ation of the boiler. Changes on these systems by non qualied persons are not allowed e.g. the settings of the
gas valve. The gas/air ratio is set to a lambda value of approximately 1.26. This corresponds with a CO2level of
9,3 % (full load). For further information see installation manual.

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CAHA Midi Installation, Usage and Maintenance Instructions
CONTENTS
1. Description - Boiler ................................................................................................................................... 6
2. Technical Data .......................................................................................................................................... 7
2.1 Component Matrix........................................................................................................................................ 8
3. Dimensions............................................................................................................................................... 8
4. Operation.................................................................................................................................................. 9
4.1 General ............................................................................................................................................................ 9
4.2 Central Heating (CH) .................................................................................................................................... 9
4.2.1 On-off room thermostat .................................................................................................................... 9
4.2.2 Optional 0-10V..................................................................................................................................... 9
4.2.2.1 0-10V DC % power control .................................................................................................. 9
4.2.2.2 0-10V DC Setpoint ............................................................................................................. 10
4.2.3 Outside Temperature Control OTC (optional) ............................................................................ 10
4.2.4 Optional digital communication ................................................................................................... 10
4.2.5 Slow start ........................................................................................................................................... 11
4.2.6 Protection against insufcient flow through boiler ................................................................... 11
4.3 Domestic Hot Water (DHW)...................................................................................................................... 12
4.3.1 External storage tank with thermostat (electric 3-way valve) ................................................. 12
4.3.2 External storage tank with NTC sensor ....................................................................................... 12
4.3.3 DHW priority/General behaviour with external storage tank................................................... 12
5. Boiler Control.......................................................................................................................................... 13
5.1 Control Panel................................................................................................................................................ 13
5.2 Push buttons on control panel................................................................................................................. 13
5.3 User menu .................................................................................................................................................... 14
5.3.1 Parameter/value setting.................................................................................................................. 14
5.3.2 Parameters accessible by user...................................................................................................... 14
5.4 Installer (technician) menu ....................................................................................................................... 17
5.4.1 Parameters accessible by installer (technician) ........................................................................ 17
5.5 Manual Chimney sweep mode................................................................................................................. 23
5.6 Disabling CH request.................................................................................................................................. 23
5.7 Service code................................................................................................................................................. 23
5.8 Tacho fan speed.......................................................................................................................................... 23
5.9 Errors ............................................................................................................................................................. 23
5.10 ECO working mode ..................................................................................................................................... 23
5.11 Holiday mode............................................................................................................................................... 23
5.12 Schedules for CH and DHW...................................................................................................................... 23
5.13 Cascade and Modbus ................................................................................................................................ 23
5.14 Parameter settings ..................................................................................................................................... 23

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CAHA Midi Installation, Usage and Maintenance Instructions
6. INSTALLATION ........................................................................................................................................ 26
6.1 Installing the boiler ..................................................................................................................................... 26
6.2 Frost protection........................................................................................................................................... 26
6.3 Water connection........................................................................................................................................ 27
6.3.1 Pump................................................................................................................................................... 27
6.3.2 Minimum flow ................................................................................................................................... 27
6.3.3 Water-treatment................................................................................................................................ 28
6.3.4 Water connection general............................................................................................................... 28
6.4 Gas connection............................................................................................................................................ 29
6.5 Air-supply and flue-gas connection......................................................................................................... 29
6.5.1 B23....................................................................................................................................................... 29
6.5.2 C33....................................................................................................................................................... 29
6.5.3 C63...................................................................................................................................................... 30
6.5.4 Pressure drop calculations............................................................................................................. 31
6.5.5 Installing flue -exhaust and air inlet .............................................................................................. 34
6.5.5.1 General................................................................................................................................. 34
6.5.5.2 Brackets, mounting............................................................................................................ 35
6.5.5.3 Sealing and JOINING......................................................................................................... 35
6.6 Electrical connection.................................................................................................................................. 36
6.6.1 Wiring diagram.................................................................................................................................. 37
6.6.2 NTC resistance table (12K)............................................................................................................. 39
6.7 Pneumatic connections............................................................................................................................. 39
6.8 PC-connection ............................................................................................................................................ 40
7. COMMISSIONING .................................................................................................................................... 41
7.1 Gas category................................................................................................................................................ 42
7.2 Adjustment % CO2and check input......................................................................................................... 43
8. ERRORS.................................................................................................................................................. 44
8.1 General .......................................................................................................................................................... 44
8.2 DHW errors................................................................................................................................................... 45
8.3 CH-errors....................................................................................................................................................... 45
8.4 Errors (hard and soft lockouts) ................................................................................................................ 45
9. ANNUAL SERVICE.................................................................................................................................... 47
9.1 Service-maintenance table........................................................................................................................ 48
CONTENTS

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CAHA Midi Installation, Usage and Maintenance Instructions
1. DESCRIPTION - BOILER
1 MANOMETER
2 DISPLAY LCD
3 POWER SWITCH
4 FUSE
5 BURNER HOOD
6 SIGHT GLASS
7 FLOW NTC
8 IGNITION ELECTRODE
10 INSPECTION COVER
11 AIR SUPPLY
12 GAS PIPE
13 AIR INTAKE RETARDER
14 OVERHEAT LIMITER SWITCH
15 GAS VALVE
16 FAN
17 FLOW
18 FLUE GAS NTC
19 RETURN
20 FLUE GAS OUT
21 SYPHON
22 SUMP INSPECTION COVER
23 RETURN NTC
24 FILL AND DRAIN VALVE
25 WATER PRESSURE SWITCH
26 AUTO AIR VENT
27 VENTURI
28 BOILER CONTROLLER (MAXSYS)
29 TERMINAL STRIP
30 AIR PRESSURE SWITCH
31 SYPHON PRESSURE SWITCH

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CAHA Midi Installation, Usage and Maintenance Instructions
2. TECHNICAL DATA
Technical data CAHA Midi series
Model 340 425 510 600
Central Heating
Nominal input max load (Hi) 340 425 510 595 kW
Nominal input min load (Hi) 68 85 102 119 kW
Nominal ouput max load 80-60 °C 331 413.1 495.7 578.3 kW
Nominal output min load 80-60°C 66 82.5 99 115.6 kW
Efciency max load 80-60 °C (Hi) 97.2 97.2 97.2 97.2 %
Efciency min load 80-60 °C (Hi) 97 97 97 97 %
Efciency max load 50-30 °C (Hi) 103.1 103.1 103.1 103.1 %
Efciency 30 % load 30 °C (return) (Hi) 108.1 108.1 108.1 108.1 %
Standing loss 5.57 7.83 8.72 10.15 kW
Fluegas
Temperature flue-gas max load 80-60 °C 65-70 65-70 65-70 65-70 °C
Temperature flue-gas min load 80-60 °C 60-65 60-65 60-65 60-65 °C
Mass-flow flue-gasses at max load G25 556 695 835 974 m3/h
Mass-flow flue-gasses at min load G25 111 139 167 195 m3/h
Maximum flue-resistance 250 250 300 300 Pa
Emission CO (Gaskeur SV) 116 110 100 90 ppm
Emission NOx (Gaskeur SV) 20 20 20 20 ppm
Types B23.C33.C63 yes yes yes yes
Gas
Gasflow max load G25 41.8 52.3 62.8 73.2 m3/h
Gasflow min load G25 8.4 10.5 12.6 14.6 m3/h
Gasflow max load G20 36 45 54 63 m3/h
Gasflow min load G20 7.2 9 10.8 12.6 m3/h
CO2 content max load G25/G20 9.3 9.3 9.3 9.3 %
CO2 content min load G25/G20 9.1 9.1 9.1 9.1 %
Water
Maximum flow temperature 85 85 85 85 °C
Content heat-exchanger (without manifolds) 36.2 43.7 51.1 58.5 ltr
Minimum/maximum operating pressure 0.8/6 0.8/6 0.8/6 0.8/6 bar
Hydraulic resistance (DT 20 nominal flow at full load 80-60 200 210 220 230 mbar
Maximum DT max load/min load 25/35 25/35 25/35 25/35 °C
Maximum waterflow 28.5 35.6 42.7 49.8 m3/h
Weight
Mass heat-exchanger* 150 180 215 245 kg
Total mass of boiler 330 365 429 464 kg
Casing
Width 700 700 700 700 mm
Depth without exhaust connection 1222 1222 1553 1553 mm
Height (including wheels) 1540 1540 1540 1540 mm
Height (without wheels) 1431 1431 1431 1431 mm
Electrical
Protection 00B 00B 00B 00B IP
Electrical voltage/frequency 230/50 230/50 230/50 230/50 V/Hz
Standby power consumption* 21 21 36 36 W
Min load power consumption* 78 78 105 105 W
Max load power consumption* 587 587 874 874 W
Maximum allowable power consumption 2300 2300 2300 2300 W
Fuse 10 10 10 10 A
* as coming from factory without extra devices connected

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CAHA Midi Installation, Usage and Maintenance Instructions
2.1 COMPONENT MATRIX
Overview of main components used in the CAHA Midi:
Part 340 425 510 600
Boiler control Honeywell Maxsys S4966V2052 S4966V2052 S4966V2052 S4966V2052
Display (user interface) DSP 49G2193 DSP 49G2193 DSP 49G2193 DSP 49G2193
Fan MVL 230 VAC G3G200-GN20-30 G3G200-GN20-30 G3G250-GN17-01 G3G250-GN17-01
Gas-valve Dungs 230 VAC MBC-700-SE-S02 MBC-700-SE-S02 MBC-700-SE-S02 MBC-700-SE-S02
Venturi Honeywell VMU500A VMU500A VMU680 VMU680
Texi Burner round 130 mm Worgas 433 529 623 718
Silencer air-inlet yes
Silencer flue-gas round 250 mm L=300mm yes double yes single yes single yes single
NTC 12 k L=50 3 3 3 3
NTC 12 k OTC optional optional optional optional
Water low pressure device 1,6/0,8 bar yes yes yes yes
Pressure difference switch 40 Pa in and 25 Pa out yes yes yes yes
Syphon pressure difference switch 12,4 mbar out yes yes yes yes
3. DIMENSIONS

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CAHA Midi Installation, Usage and Maintenance Instructions
4. OPERATION
The appliance is not to be used by children or persons with reduced physical, sensory or mental capabilities, or lack of
experience and knowledge. Children, even if being supervised, must not play with the appliance.
In the case of failure or malfunction of the appliance, do not attempt to repair it yourself. Please contact your installer.
Repairs must only be carried out by qualied technicians. Failure to comply with these requirements can compromise
the safety of the appliance.
4.1 GENERAL
The CAHA Midi is a floor standing boiler, equipped with a cast aluminium heat-exchanger. During heat demand the control-
ler activates the pump. The controller checks the air pressure switch (zero check) and increases the fan speed to perform
an airflow-check. Once the air pressure switch closes, the fan speed increases to ignition speed and a 5 second pre-purge
is performed. The water pressure sensor, gas pressure switch and siphon pressure switch are checked. When all pressure
switches are closed and the water pressure is ok, the ignition is started.
The air needed for combustion is taken in from the outside (if room sealed) or the boiler house (type B flue installation) by
the fan. The air is transported through a gas/air mixing device creating a negative pressure. This negative pressure is an
indication of the amount of air being transported. The negative pressure is supplied to the gas valve by an internal tube.
The gas valve automatically adjusts the amount of gas that will be injected into the venturi and that will be mixed with the
air-flow. This mixture is supplied to the burner.
Ignition and flame-control of the mixture is done by two separate electrodes mounted on the burnerhood.
Temperature control and safeguarding is done using two NTC sensors. The boiler monitors the sensors continuously in
order to control operation and ensure safe operation.
4.2 CENTRAL HEATING (CH)
4.2.1 ON-OFF ROOM THERMOSTAT
As standard the boiler is programmed for using an on-off room thermostat. The room thermostat has to be connected to
the pin nrs. 1 + 2 on the terminal strip. Open Therm will be recognized if connected on 1 + 2. The desired flow temperature
is adjustable, but as standard is set to 85 °C.
At CH heat request from the room thermostat (and no DHW heat request present) the CH-pump is activated after 10 sec-
onds. The controller will adjust the burner-input in such a way that a flow-temperature of 85 °C towards the CH-circuit is
achieved.
Warning : do not supply any voltage to these terminals as you may damage the controller
4.2.2 OPTIONAL 0-10V
The boiler may be controlled using a 0-10 V DC signal. Connect the negative (0V DC) to No. 3, and the positive (0-10V DC)
to No.4 on terminal strip C2.
A loop of wire must be placed between the pin nrs. 1 and 2 of terminal strip C2. In the technician menu , enable 0-10V in
the advanced CH settings menu by setting , CH request to either 0-10V DC % or 0-10V DC SP.
4.2.2.1 0-10V DC % POWER CONTROL
A value between 2 and 10V DC generates a CH power demand proportional to this value between 0 and 100% (0% = mini-
mum load, 100% = nominal load). The heat demand is removed when the control signal falls below 1 volt.
The setpoint of maximum flow temperature is set to 90°C. In the user/technician menu , under diagnostics, boiler informa-
tion the actual voltage input and target power are displayed.

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CAHA Midi Installation, Usage and Maintenance Instructions
4.2.2.2 0-10V DC SETPOINT
A value between 2 and 10V DC generates a CH setpoint demand proportional to this value between CH minimum flow tem-
perature and maximum CH flow temperature. The heat demand is removed when the control signal falls below 1 volt.
The minimum and maximum CH flow temperature can be set in the technician menu, advanced CH settings, CH tempera-
tures.
In the user/technician menu , under diagnostics, boiler information the actual voltage input and boiler setpoint are dis-
played.
Caution : Ensure that the 0-10V DC signal is free from electrical interference!
4.2.3 OUTSIDE TEMPERATURE CONTROL OTC (OPTIONAL)
The boiler may use an outdoor sensor to provide weather compensation (OTC).
To activate weather compensation connect an oudoor sensor to numbers 5 and 6 on the terminal strip C2. Pin numbers 1
and 2 have to be bridged by a wire. Alternatively those pin numbers ( 1 and 2) can be used for connecting room thermostat
on/off. In the technician menu, under advanced CH settings, CH
request, OTC only must be selected. The outdoor sensor is then
automatically detected by the controller. The parameters corre-
sponding with A-E in the gure below can be set in the techni-
cian menu (advanced CH settings).
A OTC offset: minimum CH setpoint value
B OTC setpoint maximum: maximum CH setpoint value
C OTC weather cold: external temperature value at which the
maximum CH value will be used.
D OTC weather warm: external temperature value at which the
minimum CH value will be used
E OTC warm weather shutdown: external temperature value at which the CH demand will end
In the user menu an eco setpoint reduction (night reduction) can be set. Day, week and weekend options are also available
(on, eco, off)
The outdoor sensor is available as an optional accessory.
The sensor should be installed on the north-side of the building at a height of approximately 2 meters.
Note : The resistance of the outdoor NTC should be 12 kOhm at 25 °C.
Also see table of resistance for NTC’s at 6.6.2
4.2.4 OPTIONAL DIGITAL COMMUNICATION
The boiler supports digital communication with room thermostats using Open-Therm communication protocols (automati-
cally recognised if connected to pins 1 + 2 on terminal strip C2, also see 4.2.1.)
.

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CAHA Midi Installation, Usage and Maintenance Instructions
4.2.5 SLOW START
The boiler uses the “slow start” procedure to prevent the boiler from supplying excessive power in low load situations.
After “zero check” APS and closure APS with pre purge ignition starts. Following, a stabilization period, the boiler modulates
down to low capacity and maintains this capacity for 1 minute. Subsequently the boiler power increases at a target rate
of 4 °C/min until maximum capacity or set temperature has been reached. Once heat demand has nished the burner will
turn off following a set post purge period.
The graph below illustrates this.
4.2.6 PROTECTION AGAINST INSUFFICIENT FLOW THROUGH BOILER
When the requirements of 6.3.2 are fullled the boiler will protect itself against insufcient flow. This is done by checking
the difference in temperature between flow and return (so called ΔT).
In a low flow scenario the ΔT will rise rapidly. The ΔT safe-guarding principle is as follows:
▪AtΔT > 22 the boiler starts modulating
▪AtΔT between 22 and 27 the boiler continues modulating
▪AtΔT > 27 boiler the fan speed will reduce until T < 25

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CAHA Midi Installation, Usage and Maintenance Instructions
4.3 DOMESTIC HOT WATER (DHW)
4.3.1 EXTERNAL STORAGE TANK WITH THERMOSTAT (ELECTRIC 3-WAY VALVE)
As standard the DHW conguration is factory pre-set for an external storage tank + tank thermostat.
For hydraulic connection of an external storage tank to the boiler via an electric 3 way valve one should either use :
- the default conguration 2 pumps: 230 VAC DHW pump (terminal strip C1: 12,13,14) and CH pump (terminal strip C1:
15,16,17)
- an electric 3-way valve with a maximum travel time of 255 sec. (terminal strip C1: 13,14,15,16). At the end of the travel
time in either direction DHW or CH the 230 VAC on the 3-way valve will be switched off.
The 2 wires of the tank thermostat must be connected to numbers 7 and 8 on terminal strip C2.
In the case of using an electric 3-way valve adjust the setting in the technician menu, system settings, boiler parameters,
number of pumps to: pump and 3-way valve.
The 3-way valve travel time can be changed in the technician menu, system setting, boiler parameters, 3-way valve travel
time.
4.3.2 EXTERNAL STORAGE TANK WITH NTC SENSOR
In case the storage tank is equipped with an NTC sensor, adjust the setting in technician menu, advanced DHW settings,
DHW request to sensor.
Note: The resistance of the NTC sensor must have a value of 12 kOhm at 25 °C.
The 2 wires of the tank NTC sensor must be connected to numbers 7 and 8 on terminal strip C2.
The set point temperature of the storage tank is adjustable (default set at 60°C,the flow temperature is DHW setpoint +
20K). Warning : if a CH heat demand exists immediately after nishing the heat request for DHW, it is possible for high tem-
peratures to flow into the CH system regardless of CH set point (hot shot).
4.3.3 DHW PRIORITY/GENERAL BEHAVIOUR WITH EXTERNAL STORAGE TANK
Disabling hot water operation : press Summer-Winter button R2-C4( not active in main screen). See later in manual for
further explanation.
Enabling hot water operation : press Summer-Winter button R2-C4 (active in main screen). See later in manual for further
explanation.
In the default boiler conguration, (2 pumps-DHW and CH pump), a DHW request has priority over CH request
In the technician menu, advanced DHW settings, DHW priority, the DHW priority over CH can either be disabled or a maxi-
mum DHW priority time can be set.
In the case where the DHW priority is disabled and both demands are active at the same, both pumps (CH and DHW) will
be activated. During this time the flow temperature is set to either 80 °C (tank thermostat) or DHW setpoint + 20K (NTC
sensor).
Notice : In some countries, at outputs ≥ 40 kW double separation between exchanging media is required. Please
check your local regulations.

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CAHA Midi Installation, Usage and Maintenance Instructions
5. BOILER CONTROL
5.1 CONTROL PANEL
The control panel has 12 buttons and a display as shown in the gure below.
5.2 PUSH BUTTONS ON CONTROL PANEL

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CAHA Midi Installation, Usage and Maintenance Instructions
5.3 USER MENU
By pressing the “menu-button” the display will show the text as given in the gure below.
By pressing the button marked “3”in the gure shown,
the user menu is accessed.
Pressing the button rmarked “5” returns back to the
main screen.
By pressing the button marked “4”, the installer menu is
accessed.
In the user menu the following options will be shown :
1. HEATING
2. DOMESTIC HOT WATER
3. HOLIDAY
4. MAINTENANCE
5. SETTINGS
6. CHIMNEY-SWEEPER
7. DIAGNOSTICS
By pressing up and down (R1-C2 and R3-C2) one of the six options as shown above will highlight the desired parameter. By
pressing the OK button (R2-C2) the chosen option will be selected.
Once an option has been slected it is possible to change the parameters corresponding with the chosen option.
5.3.1 PARAMETER/VALUE SETTING
Pressing the up and down (R1-C2 and R3-C2) buttons will highlight the desired parameter. Pressing the OK button (R2-C2)
will allow the chosen parameter to be modied. This is shown below.
The actual value can be changed by pressing the R1-C1
and R2-C1 buttons.
The changed value can be conrmed by pressing the
OK (R2-C2) button.
Pressing the back (R3-C1) button leaves the actual
displayed parameter.
If there are more parameters shown in the parameter
value area (4) the desired parameter can be selected by
pressing the up and down ((R1-C2 and R3-C2) buttons.
5.3.2 PARAMETERS ACCESSIBLE BY USER
An overview of the parameters accessible by the user is given on the next pages

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CAHA Midi Installation, Usage and Maintenance Instructions
USER MENU SUBMENU 1 SUBMENU 2 SUBMENU 3 SUBMENU 4 NOTES 1 Heating Heating user settings
1 CH temperature /OTC set Set the CH temperature and OTC curves parameters
1 CH setpoint Adjust setpoint of CH circuit 2 Outside tempera- ture for CH off
Set the external temperature at which Heat demand is removed . If set OFF, heat demand will never be removed.by controller (Only by removing RT or bridge between terminal strip C2:1,2)
2 ECO setpoint reduction Set the temperature that will be subtracted from the actual setpoint when
ECO mode is activated
3 Scheduler set Invoke scheduler menu
1 Enable/disable on board scheduler
Based on selection is possible to enable/disable on board scheduler
Enable Enable on board scheduler Disable Disable on board scheduler
2 Scheduler set Select to set scheduler
1 Monday 2 Tuesday 3 Wednesday 4 Thursday 5 Friday 6 Saturday 7 Sunday 8 Monday – Friday 9 Monday – Sunday 10 Saturday - Sunday
Used to program on board scheduler (On, Off , Eco)
2 Domestic hot water Domestic hot water user settings
1 DHW set point Set the DHW temperature (in case of a DHW with sensor this is the actual
DHW temperature, in case of DHW with thermostat this is the base boiler flow temperature)
2 ECO set point reduction Set the temperature that that will be subtracted from the actual setpoint
when ECO mode is activated
3 Scheduler set Invoke scheduler menu
1 Enable/disable on board scheduler
Based on selection possible to enable/disable DHW on board scheduler
Enable Enable on board scheduler Disable Disable on board scheduler
2 Scheduler set Select to set scheduler
1 Monday 2 Tuesday 3 Wednesday 4 Thursday 5 Friday 6 Saturday 7 Sunday 8 Monday – Friday 9 Monday – Sunday 10 Saturday - Sunday
Used to program on board scheduler (On, Off, Eco)

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CAHA Midi Installation, Usage and Maintenance Instructions
USER MENU SUBMENU 1 SUBMENU 2 SUBMENU 3 SUBMENU 4 NOTES 3 Holiday Holiday temperatures settings
1 CH holiday set point Set CH temperature used when Holiday mode active 2 DHW holiday set point Set DHW temperature used during holiday mode
4 Maintenance Set maintenance related info
1 Service information Used to display service company phone number or
entered info
2 Service due date Show next service due date . When date expire a MSG
is shown on lower part of main screen asking for service
5 Settings Boiler option settings
1 Select Language Allow selection of a different language
English Select for English Italian Select for Italian German Select for German Russian Select for Russian
2 Select units Allow selection of different unit
Fahrenheit Select for Fahrenheit Celsius Select for Celsius
3 Set date Allow RTC date setting 4 Set time Allow RTC time set. When selected a screen asking for
time format 24/12 Hours is opened. When selected ap- propriate format screens jump to time entering screen
24 hours Select for 24 hours clock 12 hours Select for 12 hours clock
5 Restore factory data Pressing OK all the user settings will be restored to the
original factory default settings. See 1)
6 Chimney sweeper Manual mode. Hitting OK will force boiler to operate at
% of power Timeout 15 minutes. While test in progress navigating through other menus is allowed.
7 Diagnostics Will display boiler usage information and errors
1 Boiler information Boiler information
"1 CH request 2 DHW demand 3 Firing rate 4 Flame ionization current 5 Boiler set point 6 Boiler supply tempera- ture 7 Return temperature 8 Flue temperature 9 Outdoor temperature
10 DHW storage temperature 11 Boiler fan speed 12 CH ignitions 13 CH runtime 14 DHW ignitions 15 DHW runtime 16 System pressure 17 Heat Exchanger Temp. 18 0-10V input 19 Target power"
Will display the information shown in SUBMENU 2 When the line has a * at the end of the line means that hitting OK when the line is highlighted will open a graph that shows the latest 120 variable values stored every 12 minutes (24 hour history)

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CAHA Midi Installation, Usage and Maintenance Instructions
5.4 INSTALLER (TECHNICIAN) MENU
If the button marked “4” (see page 14) is pressed the screen as given in the gure below will appear.
Please contact RVR Energy Technology Ltd to receive the technician access code.
Once the menu is accessed by entering the code the following options will be shown
1. ADVANCED CH SETTINGS
2. ADVANCED DHW SETTINGS
3. SYSTEM SETTINGS
4. DIAGNOSTICS
5. USER SETTINGS
6. CASCADE
7. RESTORE FACTORY SETTINGS
Pressing the up and down (R1-C2 and R3-C2) buttons will highlight the desired parameter group. Pressing the OK button
(R2-C2) selects the chosen parameter group.
Pressing the up and down (R1-C2 and R3-C2) buttons will highlight the desired parameter subgroup. Pressing the OK but-
ton (R2-C2) selects the chosen parameter subgroup.
Once a parameter subgroup option has been chosen it is possible to change the parameters corresponding with the select-
ed subgroup
Follow the instructions as per 5.3.1 to set or change a parameter.
5.4.1 PARAMETERS ACCESSIBLE BY INSTALLER (TECHNICIAN)
An overview of the parameters accessible by the installer (technician) is given on the following pages.
Certain paramaters are marked with a caution or warning symbol. Setting inappropriate values in these parameters may
lead to instability or overheating, or in extreme cases damage to the boiler, connected equipment, or persons. RVR does
not accept responsibility for any damage caused by inappropriate settings.
Take care when altering the value of parameters marked with the caution symbol
Parameters carrying the warning symbol have explicit directions associated with them. Failure to observe these
directions will immediately invalidate the product's warranty.

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CAHA Midi Installation, Usage and Maintenance Instructions
TECHNICIAN MENU SUBMENU 1 SUBMENU 2 SUBMENU 3 SUBMENU 4 NOTES
Lockout history Show a list of recent errors. Hitting OK on the highlighted error will open
screens that contain details on boiler status when error occurred
1 Advanced CH settings Heating installer advanced settings
1 CH power set Set power of boiler in CH mode
1 Maximum power Set % of boiler maximum power in CH mode 2 Minimum power Set % of boiler minimum power in CH mode
2 CH temperatures Set (selecting OK) and show CH temperatures
1 Absolute max temp Set CH absolute max temperature (CH temperature boiler settings will never
exceed). DO NOT EXCEED 90°C
2 CH maximum set point Determine higher boundary of CH setpoint 3 CH minimum set point Determine lower boundary of CH setpoint 4 CH set point hysteresis Set CH setpoint hysteresis (temperature above setpoint at which boiler will
be switched off)
3 OTC parameters Set the OTC parameters
1 Outside temp for max CH Dene external temperature at which OTC will set maximum CH setpoint 2 Outside temp for min CH Dene external temperature at which OTC will set the minimum CH setpoint 3 Outside temp for CH off Set the external temperature at which Heat demand is removed . If set OFF
heat demand will never be removed.by controller (Only by removing RT or bridge between terminal strip C2:1,2)
4 OTC set point table Show in a table the link between external temperature and actual setpoint
determined by the OTC parameter selection
5 OTC curve Show in a curve the link between external temperature and actual setpoint
determined by the OTC parameter selection
4 CH pump settings Set pump usage related parameters
1 post pump time Set the CH pump overrun time.
5 CH anti cycling timer
Set the ant cycling timer (minimum time between boiler goes off till next ignition)
6 CH request type Allow selection of different CH requests:
Only OTC Select OTC: outdoor Temperature controller 3) Room Tstat Select RT/OT: Room Thermostat or OpenTherm 0-10V Signal [%] Select 0-10Vdc input for Power mode 3) 0-10V Signal[SP] Select 0-10Vdc input for setpoint mode 3)
2 Advanced DHW settings Domestic hot water advanced settings
1 DHW power Set power of boiler in DHW mode
1 Maximum power Set % of boiler maximum power in DHW mode 2 Minimum power Set % of boiler minimum power in DHW mode
2 DHW temperatures Set (selecting OK) and show DHW temperatures 2 DHW temperatures Set (selecting OK) and show DHW temperatures
1 Storage temperature set point
Set Flow temperature during DHW mode when DHW done via a thermostat (Switch)
2 Boiler temperature set point
Set DHW temperature setpoint when DHW done with temperature sensor

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CAHA Midi Installation, Usage and Maintenance Instructions
TECHNICIAN MENU SUBMENU 1 SUBMENU 2 SUBMENU 3 SUBMENU 4 NOTES
3 DHW pump settings Dene pump usage in DHW mode
DHW post pump time Set the DHW pump overrun time added to the prexed time of 3 minute.
4 DHW priority Dene DHW priority over CH
1 DHW priority status Enable /disable DHW priority over CH
Enabled Enable Disabled Disable
2 DHW priority timeout Dene after how much time DHW priority is ended. (CH can be served if
present for the same amount of time).
Off Select for no timeout (While DHW priority status is enabled) 1..60 minutes Set timeout in minutes. (While DHW priority status is enabled)
5 DHW request type Dene DHW request switch or sensor
Switch DHW start when DHW thermostat closes Sensor DHW start based on required vs actual DHW temperature
3 System setting Boiler and system parameters
1 Boiler parameters Boiler related parameters
1 Ignition power Set power % used when igniting burner. DO NOT EXCEED 30% 2 Delay siphon check Delay time to validate a syphon error DO NOT ALTER 3 Number of boiler pump Dene Pump and 3-way valve or 2 pumps
Pump and 3WayValve
System with pump and 3-way valve
Two pumps System with 2 pumps
4 Pump speed max Maximum % of PWM pump speed 5 Pump speed min Minimum % of PWM pump speed 6 Antilegionella Based on selection possible to enable/disable Antilegionella protection
Enabled Enable Antilegionella protection Disabled Disable Antilegionella protection
7 Modbus parameters Set Modbus parameters
Address Set address default: 1 Baudrate Set baudrate default: 38400 bps Frame Set frame 8N!
8 3 Way valve travel time Select for setting travel time 3WV in seconds
2 User interface set- tings
1 Select language Allow selection of a different language
English Select for English Italian Select for Italian German Select for German Russian Select for Russian

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CAHA Midi Installation, Usage and Maintenance Instructions
TECHNICIAN MENU
SUBMENU 1 SUBMENU 2 SUBMENU 3 SUBMENU 4 NOTES
2 Select unites Allow selection of different unit
Fahrenheit Select for Fahrenheit Celsius Select for English
3 Set date Set system date 4 Set time Set system time
3 Service settings Service information
1 Service information Used to insert service company phone number (selection
done as per technician password enter)
2 service due date Next service due date (input done as per date entering)
4 Diagnostics Boiler information and lockout history
1 Boiler information Boiler information
"1 CH request 2 DHW demand 3 Firing rate 4 Flame ionization current 5 Boiler set point 6 Boiler supply temperature 7 Return temperature 8 Flue temperature 9 Outdoor temperature
10 DHW storage temperature 11 Boiler fan speed 12 CH ignitions 13 CH runtime 14 DHW ignitions 15 DHW runtime 16 System pressure 17 Heat Exchanger Temp. 18 0-10V input 19 Target power"
Will display the information shown in SUBMENU 2 When the line has a * at the end of the line means that hitting OK when the line is highlighted will open a graph that shows the latest 120 variable values stored every 12 minutes (24 hour history)
2 Lockout history Shows the list of recent errors. Hitting OK on the high-
lighted error will open new screen that contains details of the boiler status when the error occurred.
3 Manuel test See chimney sweeper.
5 User settings Access the user settings from the advanced menu.
1 Heating Heating user settings
1 CH temperature/ OTC set Set the CH temperature and OTC curves parameters
1 CH set point Adjust setpoint of CH circuit 2 Outside temperature for CH off
Set the external temperature at which Heat demand is removed .
2 ECO set point reduction Set the temperature that will be subtracted from the actu-
al setpoint when ECO mode is activated
3 Scheduler set Invoke scheduler menu
1 Enable/dis- able on board scheduler
Based on selection is possible to enable/disable on board scheduler
Enable Enable on board scheduler Disable Disable on board scheduler