Wijas POW 12 Installation instructions

Flow pressure water heaters
type POW 12, 18, 21, 24
INSTRUCTIONS FOR
ASSEMBLY AND OPERATION

2
Before using the heater please read the instructions carefully. In the future it will pay off in
the form of failure-free operation for a long time. Flow water heaters series POW 12, 18,
21, 24 with two-degree hydraulic switch are designed for heating utility water. Warm water
can provided to a couple of water drawing points located in different rooms. These heaters
are equipped with heating spirals that are directly washed by water. This direct heating
process prevents limescale from settling and ensures high efciency and quick heating of
water. Microprocessor system analyses the inlet water temperature and the temperature set
by a user, as well as its consumption. Based on collected data, it increases or decreases
heating power in such a way that the temperature of water at the outlet corresponded to
the one set by the user. In addition, the electronic system of the heater is equipped with
an air block sensors that decrease to the minimum the possibility of damaging immersion
heaters due to air blocking of the water supply installation. POW heaters may heat up water
that was initially heated, for example by the solar heating installation, which at the inlet of
the heater cannot exceed 60OC.
■ Thedevicecannotbeinstalledinroomsinwhichtemperaturemay
fallbelow0°C,aswellasinwhichthereisariskofexplosion.
■ This equipment is not designed to be used by persons (including
children)ofthelimitedphysical,sensoryormentaltness,unless
theiruseissupervised.
■ Attentionmustbepaidtochildrensothattheywouldnotplaywith
thedevice.
Instructionsforassembly
Installation as well as start-up of the POW heater should be done by an authorized person
in accordance with the instructions included in the Instructions. Any installation works
should be done with disconnected power and water supply. Electric installation of the heater
should be made pursuant to the binding regulations. The device should be permanently
connected to an electrical installation with an earth terminal. Electrical installation should be
equipped with a residual circuit breaker with the protection against electric shock, as well
as a breaker ensuring the disconnecting of the device from the source of power supply in
which the distance between contacts should be not less than 3 mm.
1. To the place in which the heater is to be installed, electrical as well as water installation
should be supplied using the assembly template for that.
2. Drill holes and insert expansion plug.
3. After supplying cold water, install the control valve with a lter (pict. 3).
4. Unscrew the located at the bottom of the heater casing screw fastening the casing
(pict. 1), take off the cover and disconnect the belt cable by taking out the plug from
the socked marked “DISPLAY” (pict. 2).
5. Screw the heater to the wall with the fastening screws, having previously led the supply
cable through the hole.
6. Check the turning on of the pressure switch.
7. Remove blanking plugs from water connections.

3
Pict. 1. Casing of the heater
1. Display
2. Button increasing the set temperature
3. Button decreasing the set temperature
4. The screw fastening the casing
Pict. 2. Display plate with belt cable
1. Plug
2. “DISPLAY” socket
3. Display plate
8. Connect the heater to water installation (pict. supply connection marked 14, outlet
marked 15)
9. Switch on the water feeding the heater and check the watertightness of connections.
10. Connect the heater to the electrical installation as shown on pict. 4.
11. Connect the belt cable by plugging the plug to the socket “DISPLAY”(pict.2).
12. Place the casing and screw with the fastening screw.

4
Start-up
In order to remove air from the water installation and the heater prior to turning on electric
power, open warm water valve for about 20 seconds. Then turn on the power. After turning
on the heating, warm water valve should be opened again waiting till the moment (approx.
5 sec.) when the device will be in standby. A short sound signal and increased brightness
of the display will signal the start of the water heating process. Close warm water valve.
The heater will turn off heating signalling it with two short sound signals and the decreased
brightness of the display. By means of “+” button, the desired temperature of water heating
can be set.
Pict. 3.
Pict. 4. Diagram of electrical installation

5
Use
Setting the water temperature is done by pressing one of the buttons located under the
display marked with “–” or “+” signs (pict. 1) in the range from 30OC to 60OC.
Detecting by the heating system bigger ow than the 2.9 l/min will result in switching it on
what is signalled with brighter lighting of the display. The drop of the ow below the point of
turning on will result in turning off signalled with decreasing of the brightness of the display.
When the water ow through the heater is too strong in relation to the set temperature, the
display will signal it displaying the “–” signs alternatively with the set heating temperature.
In case when the inlet temperature exceeds 40OC, the heater will turn off to the moment
when the feedwater temperature drops below 46OC.
Water
temperature
at the inlet
Water temperature at heater outlet
40OC
Water temperature at heater outlet
50OC
POW
12
POW
18
POW
21
POW
24
POW
12
POW
18
POW
21
POW
24
5OC 4,9 7,4 8,7 9.9 3,9 5,8 6,7 7,7
10OC 5,8 8,6 10 11,5 4,3 6,5 7,6 8,7
15OC 6,9 10,5 12,1 13,8 4,9 7,4 8,7 9,9
Efciency of warm water depends on the temperature of inlet water.
Cleaningthewaterlter
In a situation when the lter is partially or fully blocked, follow the steps:
1. Disconnect the power supply
2. Unscrew the fastening screw located at the bottom of the casing (pict. 1), then take the
casing off holding it in such a distance from the heater so that the belt cable connecting
the display with the heater was not stretched, and then disconnect the cable by taking
out the plug from the socket marked “DISPLAY” (pict. 2).
3. Close the control valve (marked 1).
4. Open the plug of the control valve (marked 2).
5. Take out mesh lter (marked 3).
6. Remove dirt
7. Insert mesh lter
8. Close the valve plug.
9. Open the ow on the control valve and check the watertightness of connections.
10. Connect the belt cable to the display plate (pict. 2).
11. Close the casing
12. Perform the air relief of the heater, and then start it according to chapter “Start-up”.

6
Pict. 5. Control valve with a lter
1. Control valve knob
(position: ow closed)
2. Valve plug
3. Mesh lter
Mulfunctioningoftheheater
Removing the given below causes of mulfunctioning of the heater is not included in manu-
facturer’s warranty. In case when none of the causes occurs, please contact a service point.
Displaydoesnotlight:
- not connected belt cable connecting driver plate with the display (pict. 2)
- defect of the power supply installation of the heater.
Toolowwaterow:
- blocked water lter
- too low water pressure
- control valve closed too much
- not fully opened main valve. The heater does not heat or barely heats.
- wrong hydraulic assembly, defect of the electric installation powering the heater
Theheaterdoesnotheatwatertothesettemperature:
- too large drop of mains voltage after turning on of the heater.
- too large ow of water (see point “Use”).

7
1. Lower casing
2. Upper casing
3. Display plate with a keyboard.
4. Heating unit
5. Flow sensor.
6. Air block sensors.
7. Inlet water temperature sensor.
8. Thermal switch
9. Pressure switch
10. Network terminals being parts of the
pressure switch
11. Hole for inserting the supply cable
12. Driver plate.
13. Power plate.
14. Connection of feedwater (cold)
15. Connection of feedwater (warm)
16. Terminal of the protective cable
Internalstructureofthedevice
Pict. 6.

8
Pict. 7. Schematic diagram POW 12
1 - thermal switch
2 - display and keyboard plate
3 - driver plate
4 - power plate
5 - temperature sensor
6 - ow sensor
7 - heating unit
8, 9 - air block and ow sensors
10 - pressure switch
PE - terminal of the protective cable
E - electrode
G1, G2, G3, G4 - immersion heaters

9
Pict. 8. Schematic diagram POW 18, 21, 24

10
Contentsofthepackaging
POW heater 1 pcs.
Control valve 1 pcs.
Fastening screws with expansion plugs 3 pcs.
Gaskets 2 pcs.
Template 1 pcs.
Instructions manual 1 pcs.
Warranty card 1 pcs.
POWheater 12 18 21 24
Rated power kW 12 18 21 24
Supply voltage 400 V 3~
Frequency Hz 50
Maximum power consumption A 17,3 26 30,3 34,6
Minimum cross-section
of connection cables mm24 x 2,5 4 x 4 4 x 4 4 x 6
Maximum cross-section
of connection cables mm24 x 10
Rated current of the circuit breaker A 25 32 40 40
Minimum electrical resistivity
of water at 15OCΩcm 1300
Pressure of feedwater MPa 0,1 – 0,6
Minimum turning on ow l/min 2,9
Maximum temperature of feedwater OC 60
Water connection G ½”
Dimensions
(height x width x depth) mm 447 x 235 x 104
Mass kg 3,8
Technicaldata

11

12