E.C.A. GP11 User manual

GP 11/13/16/20/24 kW HM
HERMETIC MONOTERMIC COMBI
BOILER
SERVICE MANUAL

1. PRODUCT NOTATION
GP 11/13/16/20/24 HM
Definition
E.C.A. GP 11/13/16/20/24 kW Hermetic Combi (monothermic
model)
2. SAFETY SYSTEMS
With the safety systems in your device, both you and your device are fully secured. These safety
systems;
Flame Loss Protection
Boiler Over-heat Safety System (105°C)
DHW (Domestic Hot Water) Over-heat Safety System (71°C)
CH (Central Heating Water) Over-heat Safety System (95°C)
High Water Pressure Protection System (3 bar)
Low Water Pressure Protection System (0,8 bar)
Low Voltage Protection System (165 V AC)
Thermal Accumulation Protection System (with by-pass circuit and pump over-run)
Frost Protection System (The appliance must be on stand-by to activate the frost
protection)
Water Flow Inspection.
Pump Dry Run Protection System
3 Way Valve Anti-sticking Function
Automatic Air Vent
Expansion Vessel (6L)
3. GENERAL FEATURES
11 kW 13 kW 16 kW 20 kW 24 kW
Category
Type
Gas Inlet Pressure (Natural Gas G20) mbar
Power Unit
Pmin, heating power (thermal power) kW
Pmax, heating power (thermal power) kW 11,3 13 16 20 23,3
Qmin. Thermal Load kW
Qmax. Thermal Load kW 12,8 14,8 17,9 22,3 25,6
Gas Consumption Unit
Natural Gas (at full power)
m3/h 1,38 1,58 1,93 2,41 2,76
Natural Gas (at min. power)
m3/h
NOx Class
Central Heating Unit
Min. Water Pressure bar
Max. Water Pressure bar
Operation Range (@Radiator heating)
°C
Operation Range (@Underfloor heating)
°C
30 - 50
0,8
3
30 - 80
8,2
9,2
0,96
3
20
Unit
GP
Product Type
I2H
C12(X), C32(X),*C42(X),*C52(X)

*If the twin chimney outlet is not available, a twin chimney adapter should be used to install these
chimney types.
4. IMPORTANT INFOS AND WARNINGS
WARNING-1: The device is consist of sheet metals which have sharp edges that may cause
injuries. Service operation must be done by only authorized people. Proper personel
protective equipments must be used during service operations.
Info-1: Service reminder function will be activated if the input power is supplied to the control board for
7500 hours. SE will be displayed together with the service icon on the user interface. Control board
continues normal operation during service reminder function. Service reminder must be cancelled
by RESET knob. After resetting the service reminder by RESET knob, service reminder will be
activated again for 2 more times in 72 hours. After 3rd resetting of service reminder function, it will
be activated again after 7500 hours.
Service reminder time is cleared and 7500 hours counting is restarted if 20 is written to PP31.
Parameter
No
Parameter Name
Parameter Value Definition
Factory
Setting
Range
PP31
Parameters Factory Setting
0
0 - 99
20: service reminder time cleared
45: all parameters are set to factory defaults
70: fault history logs are all cleared
Info-2: To connect the room thermostat, firstly PP30 ON-OFF Room Thermostat Selection parameter’s
value must be changed to ON_OFF room thermostat available (1), otherwise boiler doesn’t run
according to room thermostat.
Parameter
No
Parameter Name
Parameter Value Definition
Factory
Setting
Range
PP30
ON-OFF Room Thermostat Selection
0
0 - 1
0: ON_OFF room thermostat not available
1: ON_OFF room thermostat available
Domestic Hot Water Unit
Min. Flow Rate l/min
Max. Flow Rate l/min
Min. Water Pressure bar
Max. Water Pressure bar
Operation Range
°C
General Unit
Electric supply V AC-Hz
Electric Consumption Watt
Protection Class
Expansion Vessel l
Weight (without packaging) kg
Dimensions mm
230 VAC-50 Hz
119
IPx4D
6
30
720*400*330
0,3
10
35 - 64
3
10 (∆T=33,4°C)

Info-3: To connect the outdoor NTC probe, firstly PP15 Outdoor sensor type parameter’s value must be
changed to Outdoor sensor available (1). Outdoor temperature measurement starts only if PP15 is
selected as 1. If PP15 is selected as 1 and outdoor NTC probe is not connected F6 error code is shown
on the display but boiler keeps working.
When the power supply is switched ON, OC, showed on LCD display, means that the probe is correctly
connected and the function enabled
Parameter
No
Parameter Name
Parameter Value Definition
Factory
Setting
Range
PP15
Outdoor Sensor Type
0
0 - 1
0: Outdoor sensor not available
1: Outdoor sensor available
5. CONNECTION DIAGRAM
1. Room Thermostat ON-OFF
2. Gas Valve Modulator
3. CH Flow NTC Probe
4. Water Pressure Sensor
5. Over Temperature Protector
6. APS
7. DHW NTC Probe
8. Flowmeter
9. Outdoor NTC probe (Ops.)
10. Pump
11. Fan
12. Gas Valve
13. Power Supply
14. 3 Way Valve
15. DHW Potentiometer
16. CH Potentiometer
17. On/Off/Reset/Summer/Winter
Potentiometer
18. Fuse
19. LCD
20. Error LED
21. Ignition and Ionization Electrode

6. CONTROL PANEL
1. Position Selection Knob (Winter, OFF/Reset, Summer Mode)
2. CH Water Temperature Set Knob
3. DHW Water Temperature Set Knob
4. Malfunction Warning LED
6.1 POSITION SELECTION KNOB (WINTER, OFF/RESET, SUMMER MODE)
When this knob turns to left, device runs according to ““ mode and ready to CH and DHW heating requests.
When this knob at middle position, device will be on OFF/standby mode. At that mode, frost protection is ready
to activate.
When device gave a fault; turn knob to OFF position and wait 3 second for fixing the fault and then turn previous
mode.
When this knob turns to left, device runs according to “ ” mode and ready to only DHW heating requests.
6.2 CH WATER TEMPERATURE SET KNOB
CH water temperature can be set with using ““ knob between 30 - 80°C.
6.3 DHW WATER TEMPERATURE SET KNOB
CH water temperature can be set with using “ “ knob between 35 - 64°C.
6.4 MALFUNCTION WARNING LED
This LED will be activated, when device gave a fault. At that way, user can notice fault easily.
4
1
3
2

7. PARAMETER MENU
Parameter Setting:
It’s necessary to perform the following sequence to enter parameter menu and make modifications in the menu:
Move P2 (CH knob) to maximum position.
Move P3 to “OFF” position and subsequently to “WINTER” position quickly.
Repeat step 2 four times and then leave knob in “WINTER” position. Parameter menu is entered
with displaying “P” and “Parameter No” consequently. Parameter no is 1 after entrance.
To increase the parameter no, move P3 to “OFF” position and subsequently to “WINTER”
position.
After reaching the desired parameter no, move P3 to “OFF” position and wait for 5 seconds.
Display will show the parameter value.
To change the parameter value, move P3 to “WINTER” position. Move P1 (DHW knob) to modify
the value of selected parameter.
Move P3 to “OFF” position. Wait for 5 seconds to store new value.
It is now possible to select another parameter.
Move P2(CH knob) when P3 is in WINTER position to exit from parameter menu.
Note 1: If no movement is done with P3 in 2 minutes during parameter menu, menu is automatically exited
after 2 minutes.
Note 2: If the boiler is operating in CH mode while “PP07 CH Max Capacity” modification, the selected value
is not immediately applied to gas valve modulator, it is applied to the modulator after storing the new
parameter.
Note 3: All parameters are set to their factory settings if 45 is written to PP31.
P2
P3
P1

8. SERVICE PARAMETER LIST

9. OPERATION PARAMETERS

10. FAULT HISTORY MENU
Last occurred 10 errors are logged in fault history menu. L0 shows the latest error, L9 shows the oldest error. If
a new error occurs it is logged in L0 and all the logs are switched to a bigger log.
It’s necessary to perform the following sequence to enter fault history menu:
Move P2 (CH knob) to minimum position.
Move P3 to “OFF” position and subsequently to “WINTER” position quickly.
Repeat step 2 four times and then leave knob in “WINTER” position. Fault history menu is
entered with displaying “L0”.
For example if the latest occurred error is F01, it is logged in L0 and seen as below:
To increase the log no, move P3 to “OFF” position and subsequently to “WINTER” position.
For example if only 2 errors occurred they are logged into L0 and L1; L2 should be empty:
Move P2(CH knob) when P3 is in WINTER position to exit from fault history menu.
If no movement is done with P3 in 2 minutes during Fault History menu, menu is automatically exited after 2
minutes.
All history logs are cleared if 70 is written to PP31.
P2
P3
P1

11. HATA KODLARI (Error Codes)
FAILURE TYPE
FAILURE
CODE
DESCRIPTION
Air Pressure Switch short
F5
When heat demand is available, if APS is closed for 15sec although FAN
is stopped, this error is given. When APS is opened, normal operation is
started automatically.
Air Pressure Switch open
F5
If APS is opened for 15sec although FAN is run, this error is given.
When APS is closed while fan is running, normal operation is started
automatically.
Outdoor probe error
F6
If Outdoor NTC probe is available and the temperature measured by
this probe is above 70°C or outdoor sensor is short circuit; this error is
given. CH operation keeps operating as if system is configured without
outdoor sensor. Normal operation starts when the error condition is
disappeared.
Low Water Pressure error
F7
If water pressure is <= 0.4bar this error is given. Error is cleared
automatically if water pressure >= 0.8bar
Water pressure display also shows the actual pressure value during F7
error.
Safety thermostat open
F1
If safety thermostat is opened for 3 sec this lockout is given. RESET
potentiometer action is required in order to reset the failure.
DHW NTC probe error
F2
If DHW NTC probe is open or short circuit, or it is damaged this error is
given. Normal operation is started when error is disappeared. This
error is not given during CH operation.
CH flow NTC probe error
F3
If CH flow NTC probe is open or short circuit, or it is damaged this error
is given. Both DHW and CH demand is stopped during this error.
Normal operation is restarted when error is disappeared.
Ionization error
F4
If there are 3 consecutive flame errors when Gas Type is selected as NG
or 1 flame error when Gas Type is selected as LPG, this lockout is given.
RESET potentiometer action is required in order to reset the failure.
Ionization component
error
F0
In case of an out-of-range ionization signal for 15 seconds this error is
given. Normal operation is started automatically when the error
condition is disappeared for 2 seconds.
False flame error
F4
If there is a false flame condition for 10 seconds, this error is given.
Normal operation is started automatically when the error condition is
disappeared.
Gas valve feedback error
F9
If there is an error in gas valve feedback check circuitry, this lockout is
given. RESET potentiometer action is required in order to reset the
failure.
Low voltage error
F8
If supply line voltage is below 155 ±15V, this error is given. Normal
operation restarts when voltage is higher than 160 ±15V.
High Water Pressure error
F15
If water pressure is >=2.8bar this error is given. Boiler keeps working.
If water pressure is >=3.5bar this error is given. Boiler stops working.
Error is cleared automatically if water pressure <=2.6bar.
Water pressure display also shows the actual pressure value during F15
error.

CH NTC High Temperature
Error During DHW
F16
If CH Flow NTC is higher than 90°C during DHW operation, burner is
stopped and F16 error is given. When CH Flow NTC is below 80°C error
is cleared and normal operation is restarted.
When DHW flow is closed during this error, error is cleared.
12. OPERATION MODES
OFF MODE
The boiler enters OFF mode when P3 is adjusted to OFF position. Pump is off, if pump overrun time
is elapsed, otherwise it is on. Fan is off, if fan overrun time is elapsed, otherwise it is on. DHW and
CH modes are inactive. LCD display is blank. Antifreeze and antiblocking functions are active.
AIR PURGE FUNCTION
Air purge function helps for the pump secure operation by reducing the air bubbles.
This function is activated:
On power-on: If the device is not in OFF position and if there is not DHW demand this fuction
is activated. If DHW heat demand is available on power-on, firstly DHW demand is supplied,
air purge is started after DHW is closed. If the device is in OFF position on power-on, air purge
is started after taking P3 to WINTER or SUMMER position.
After manual resetting of F1(Safety Thermostat Open) lockout
After CH water pressure is built up to the normal level after F7(Low Water Pressure) and
F15(High Water Pressure) errors.
DHW heating has more priority than air purge function. If a DHW demand is received during air
purge, air purge is stopped, DHW demand is supplied, after DHW demand air purge is restarted.
Air purge function can be stopped by taking P3 to OFF position.
Air purge function runs for 240 sec (3WV in CH position for the first 90 seconds, then 3WV in DHW
position for 60 seconds, then again in CH position for 90 seconds). During air purge, pump is ON
for 10 seconds and pump is OFF for 5 seconds continuously.
Display shows AP during this function.
P2
P3
P1

CH HEATING MODE
CH Heating Mode is enabled when P3 Knob is on winter position otherwise CH mode is disabled.
If the water temperature, measured by the CH flow NTC probe, is under the low limit (CH flow
temperature ON in table1) for the CH set-point and heat demand is requested on room thermostat
input (when PP30 is selected as ON_OFF room thermostat available); the burner is turned on. For
CH operation, first fan and pump are energized, then APS check is done and ignition is started.
If the boiler is on for the first time, APS check is done for both of the 2 conditions, APS is checked
to be closed after fan is on and then fan is off and APS is checked to be opened.
For the first two minutes after ignition, minimum current is applied to the modulation valve. After
two minutes, modulation current is controlled with a PID algorithm to set the CH temperature to
CH SET temperature.
Pump is on for “always” or “45 seconds”, during antifast cycling time according to the parameter
“PP06 Pump Operation in CH AFCT Time”. If room thermostat input is opened, pump is on for 45
seconds.
After every heat demand request end, a fan overrun (Fan overrun time) is done.
Radiator symbol is flashing during CH heating operation and CH flow NTC probe temperature is
displayed on LCD. Flame symbol is ON if the flame is available.
DHW INSTANTENOUS HEATING MODE
The DHW Instantaneous function has higher priority than the central heating function.
DHW Instantaneous Heating Mode is enabled when P3 knob is on winter or summer position. Flow
can be detected by a switch or sensor according to parameter “PP12 DHW Flow CH Pressure Type”.
If water flow is detected for 1,5 seconds by flow switch or flow sensor, boiler enters into DHW
operation. On DHW mode entrance fan is energized. Pump is also energized. After checking the air
pressure switch, ignition is enabled. After flame detection, flame modulation is done with a PID
type algorithm till the achievement of the DHW set point.
Aim is to set the water temperature to DHW SET temperature, for this purpose the modulator
current is controlled with a PID algorithm. But, if the water temperature measured by the DHW
NTC probe goes over the high limit (DHW temperature OFF), the burner is turned off. When it’s
under the low limit (DHW temperature ON in table 1), the boiler is turned on again.
DHW heating demand request is stopped when water flow detection is stopped. Pump and fan are
run till their overrun times.
DHW (tap) symbol is flashing during DHW heating operation and DHW NTC probe temperature is
displayed on LCD. Flame symbol is ON if the flame is available.
If DHW sensor error occurs “F2” error is given and DHW heating is stopped. But CH heating
operation goes on.

OPERATION WITH OUTDOOR NTC PROBE
The system is prearranged for the connection to an NTC sensor, which measures the external
temperature outside the building in which the installation is placed. The available adjustments in
this heating mode are the calculated center CH Set Temperature and the heat dispersion
coefficient of the room walls. To connect the outdoor NTC probe, firstly PP15 Outdoor sensor type
parameter’s value must be changed to Outdoor sensor available (1). Outdoor temperature
measurement starts only if PP15 is selected as 1. If PP15 is selected as 1 and outdoor NTC probe is
not connected F6 error code is shown on the display but boiler keeps working.
Note: The set-point calculated by the external probe formula is never higher than the maximum
temperature range and never lower than the minimum temperature range of the wall / floor
central heating. CH Set Temperature is calculated according to the below graphics.

SERVICE REMINDER FUNCTION
Service reminder function will be activated if the input power is supplied to the control board for
7500 hours. SE will be displayed together with the service icon on the user interface. Control board
continues normal operation during service reminder function. Service reminder must be cancelled
by RESET knob. After resetting the service reminder by RESET knob, service reminder will be
activated again for 2 more times in 72 hours. After 3rd resetting of service reminder function, it
will be activated again after 7500 hours.
Service reminder time is cleared and 7500 hours counting is restarted if 20 is written to PP31.
ANTIFREEZE FUNCTION
If the water temperature, measured by the CH flow NTC probe is under the low limit for “No-frost
ON temperature in table 1”, the burner is turned on. After flame detection the modulation level is
set to the minimum. If the CH flow NTC probe temperature goes over the high limit for the “No-
frost OFF temperature in table 1”, the burner is turned off. The antifreeze function operates in the
mode SUMMER or OFF or WINTER when the heat demand is not available on room thermostat
inputs. In lock-out condition only the pump is energized.
If No-frost temperature OFF value is not reached in a period (No-frost timeout period) antifreeze
is stopped and pump is energized for 3 min.
During antifreeze function, display shows “AF” and CH temperature alternately.

13. GAS CONVERSION
This device is useable with only naturel gas. LPG version is not available, so gas conversion isn’t necessary.
14. GAS PRESSURE ADJUSTMENT
As the heating capacity of the device is directly dependent on gas pressure, the device’s (mechanically) minimum
and maximum heating capacity becomes adjusted by the determination of operation pressure range.
15. SERVICE MODE
Power off the control board
Adjust the knob positions to P1 maximum, P2 minimum, P3 OFF
Power on the boiler and observe the “CC” written on the display, after seeing the “CC” adjust
the P2 to maximum.
Info : The special parameter setting sequence is available to disable the minimum
modulator current for the first 2 minutes of each burner operation
P2
P3
P1

Setting the maximum outlet pressure;
The device is taken to maximum operation position.
Gas outlet pressure measurement port’s screw is loosened.
U manometer is connected to gas outlet pressure (ø9 mm) measurement port.
After removing the protection cap of maximum pressure regulator’s adjustment screw –shown by no 2
in Figure- , the gas flow towards the burner increases by slowly turning it clockwise, and otherwise it
decreases.
By monitoring the pressure values from U manometer, the required pressure value is obtained. Setting
of maximum outlet pressure is made only for natural gas, the adjust screw of maximum pressure
regulator is completely tightened.
Setting the minimum outlet pressure;
The device is taken to minimum operation by removing one of the gas modulation cables.
Gas outlet pressure measurement port’s screw is loosened.
Gas flow decreases by turning the minimum pressure regulator’s adjustment screw –shown by no 1 in
Figure- clockwise, and otherwise it increases.
The required pressure value is obtained by monitoring the pressure values from U manometer.
After making the setting, the screw removed from the outlet pressure measurement port is fastened
again and tightened for the measurement of gas valve’s outlet pressure.
The removed front panel and control panel are fastened again.
ECA GP 24 HM
Natural Gas
Max. Gas Pressure (mbar)
12,3
Min. Gas Pressure (mbar)
1,4
ECA GP 24 HM
CH
Capacity
P07
Parameter
Value
11,3
51
13
60
16
70
20
82
24
99

16. MAIN COMPONENTS
Mainboard
The mainboard operates at 230V AC, 50Hz and controls the gas valve, fan, circulation pump and 3-way
valve. A dynamic air pressure test is performed before each ignition cycle. The limit thermostat
provides an extra level of safety. Whether or not the burner is flame is continuously checked by
ionisation. The signals from the NTCs assess the need for heat and ensure safe operation. The
mainboard provides the operating functions and safety of the device. The mainboard is covered with
a plastic housing and has IP4XD safety class. The mainboard functions are made by the 2
microprocessors (low voltage and high voltage microprocessors) included. The mainboard consists of
2 parts: the high voltage side and the low voltage side. There are microprocessors on both sides. There
is continuous communication between microprocessors. A lot of data is sent from one section to
another for control and comparison.
Gas Valve
The gas valve modulates the flow of gas to the burner. The gas valve has 2 valves. First valve, on / off
safety valve. The second is the main valve (modulating valve) which provides both safety and
modulated gas control. The minimum and maximum operating pressures can be adjusted mechanically
via the gas valve. The modulation valve is set with the maximum output pressure, the maximum
pressure regulator adjustment screw. The minimum outlet pressure is set using the mechanical
minimum adjustment screw (see Gas pressure adjustment).
Burner
The burner is the place where the gas coming from
the gas valve is burned. An 11-bladed burner is
used for 24 kW combi boilers.
Injector diameter in the use of NG: 1,32 mm
Gas inlet connection: G3/4 (External thread)
Ignition –Ionisation Electrode
The device has a single electrode and it is used for ignition and ionisation. The ignition on the burner
leads to burning of the burner by generating a spark with high voltage from the mainboard. Ionisation
electrode generates a current to inform the electronic card whether a flame has formed in the burner
and controls it throughout the burning period.
Attention: To disassemble electrodes, burner should be removed.
Heat Exchanger
The heat exchanger is a component that transfers the energy generated by the burning of
the gas to the installation water. Monothermic heat exchangers only have central heating
water heated, so there is only one water inlet and outlet. In monothermic models, Domestic
hot water is heated by means of a second heat exchanger (plate exchanger).

Hydroblock
There is a pump, 3 bar safety valve, filling valve, water pressure sensor, plate exchanger, turbine, 3
way motorized valve and immersion/surface NTC on this hydroblocks.
The pump suction is from the left side of the pump and the exit is upside as shown in the figure below.
Filling Tap
Filling tap has a basic structure. To fill the system, open the valve by turning.
When the water pressure reaches between 1,0 - 1,5 bars, filling tap can be closed.
Disassemble of filling tap:
Firstly disassemble the flow manifold and turn the tap.
Assemble of filling tap:
Turn the tap until closing the filling tap.
Pump
Pump central heating (central heating system) provides circulation of water. Also, in monothermic
models, the pump allows the central heating water to be circulated in the boiler, thus domestic hot
water is heated by water passing through plate heat exchanger. The pump is located on the
hydroblock. It has 3 speed range that can be adjusted. The pump has expansion tank connection hole
and an automatic air purge.

Maximum Power
75W
Speed Stage
3
Pump Water Outlet
Connection
G3/4 (External Thead)
Manometer Connection
Closed
Drain Valve
Integrated pump
Water Pressure Sensor
The water pressure sensor prevents the device from operating at low water pressure. When the water
pressure at the central heating circuit falls below 0.4 bar, the normally open water pressure sensor
closes and blocks the operation of the mainboard combination with the signal from the water pressure
sensor. When the water pressure rises above 0.8 bar, the boiler returns to normaloperation. The water
pressure sensor is located on the flow manifold (in the central heating flow line). Sensors are
assembling with clips. Option 1 and 2 are using same water pressure sensor.
Plate Heat Exchanger
The plate exchanger is a second exchanger that provides heating of the domestic hot water in
monothermic models. When hot water is needed, the 3-way motorized valve directs the central
heating water from the main exchanger to the plate heat exchanger. The plate heat exchanger allows
heat to be transferred to the domestic hot water as it passes through the central heating water. For
24 kW combi boiler, 10 plate plate heat exchanger is used. The plate exchanger is mounted on the
hydroblock with 2 imbus bolts. O-ring sealing is provided at the inlet and outlet of domestic hot water
and central heating water.
Turbine (Water Flow Sensor)
Turbine measures domestic hot water flow. In both bitermic and monothermic models, it is integrated
in the hydroblock (return manifold). When the water is flowing, the turbine turns and forms a magnetic
field. The Hall effect sensor collects the generated magnetic field and informs the electronic card. The
electronic card controls the operation of the hot water according to the frequency values from the
turbine type. When the water flow frequency reaches 3 lt/min, the hot water enters the operating
circuit and when it falls below 2,5 lt / min the hot water operation ends.

3 Bar Safety Valve
The 3 bar safety valve protects the central heating circuit and the device against a possible
increase in pressure. When the water pressure at the central heating circuit exceeds 3 bar, the
safety valve is opened to reduce the water pressure (safety valve output drainage should be
provided). The 3 bar safety valve is located in the central heating flow line on the hydroblock.
DHW –CH Temperature Sensor (NTC)
The device have 2 NTC (Negative Temperature Coefficient). On of that is immersion type at DHW
outlet, other is surface type at CH outlet. The principle of this type of sensors; The temperature is
inversely proportional to the sensor resistance, the sensor resistance decreases as the temperature
increases, or the sensor resistance increases as the temperature decreases. NTC sensors are usually
identified with nominal resistance values of 25 ° C. However, this value does not fully define the
nominal R-T curve of the NTC. (25°C 10kΩ β3435)
The temperature sensors measure the water
temperatures of the domestic hot water and
the central heating (central heating system)
and signal the electronic board. The surface
type temperature sensor is connected to the
heating pipe by a clip. Immersion type
temperature sensors are mounted on
hydroblock (flow manifold) by a clips.
Surface Type NTC Immersion Type NTC
3 Way Motorized Valve
The 3-way motorized valve directs the central
heating water from the main exchanger to the
plate heat exchanger when it needs domestic
hot water in monothermic models. When hot
water is needed, the valve returns to its original
position, allowing the central heating to
continue.