MONDEX Tahko 6.6 User manual

12/2022
INSTALLATION AND
OPERATING INSTRUCTIONS
Tahko M, E2 and O Types

Installation and Operating Instructions Tahko
2
Contents
1 General safety instructions 3
2 Tahko heater M and E2 types 4
3 Heater assembly and installation 4
Stacking the stones 5
4 Technical specifications 6
Heater power and voltage 6
Heater dimensions 6
Required amount of stones 6
Minimum distances to inflammable material 7
5 General instructions for users of Tahko heaters 8
Note 8
Installation cable 8
Additional connection options 8
6 Things to keep in mind when using the heater 8
First heating 8
Sauna room 8
Temperature control 8
Heating time 8
Water thrown on heater 8
Sauna room construction 9
7 Wiring diagram M type 9
8 Time switch and thermostat operation M type 10
Additional connection options 10
9 Installation instructions E2 type 11
Installation of controller and sensor 12
10 Wiring diagram E2 type 13
Controller card wiring, heater 13
Controller card wiring, controller 13
11 Heater control and operation, type E2 14
Switching on the heater 14
Starting the heating process 14
Timing of the heating process 14
Starting the heating 14
Stopping the heating or timing process 15
Quick start of the heating process 15
Parental control 15
Error codes 15
12 Heater control and operation, O type 16
13 Troubleshooting 17
Heater does not heat up 17
Warnings 17
Warranty 17
Maintenance, spare parts 17
Natural stone as a material 17
Changing the heater stones 17
14 Service history 18

Installation and Operating Instructions Tahko
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This device may be used by children who are 8 years of age or older, as well as by persons whose
physical, sensory or mental abilities have deteriorated or who lack of experience and knowledge, only
under supervision or when they have been instructed on the safe use of the device and they understand
the hazards associated with using the device.
This device complies with the requirements of:
Mondex pursues an active policy of product development and continuous improvement. For this
reason, Mondex reserves the right to make changes relating to the design and technical specifications
of their products without prior notice.
1. General safety information
Electrical connections may only be made by an electrician with a valid installation authorisation
according to the current regulations.
The Mondex electric heater is suitable for use in a family sauna, one (1) heater per sauna room.
Retain the installation and operating instructions for further reference.
Always check the adequacy of the fire protection distances!
Failure to observe the connection instructions may cause a fire hazard!
Always check the sauna room before switching the heater on!
Always check that the controller has switched the heater off after the set time period!
Due to the risk of fire, do not use the sauna to dry clothes or laundry.
Exercise caution with a hot heater, since the heater stones and metal parts become very
hot and can cause burns.
Steam from the heater is burning hot and may cause severe burns.
Children, disabled and ill persons who are using the sauna should be supervised.
Children may not play with the device.
A child must not carry out any cleaning or maintenance unattended.
Benches and floors may be slippery, therefore move in the sauna with caution.
Do not go to a hot sauna under the influence of narcotic substances
(alcohol, drugs, narcotics, etc.).
A stone compartment without stones or filled improperly will present a risk of fire!
Covering the heater will present a risk of fire.
To ensure safe use of the sauna, please read these safety instructions first!

Installation and Operating Instructions Tahko
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2. Tahko heater models
M type heater Heater type E2
+
Heater assembly
1) Keep the heater in its original package in an upright position in a warm
and dry location until it is installed.
2) The package includes the heater, as well as for type E2, the thermostat
sensor, electronic controller and required cables. Inspect the heater
components visually. If you notice any discrepancies, please contact the
store from which you purchased the heater. Do not expose heater parts
to blows and denting when taking it out of the package. The sauna’s
floor surface should also be properly protected before you begin the
installation.
3) An electrician should connect the wires before the heater is installed. If
the heater is to be embedded in the bench structure, it must be lowered
through the benches before making the electrical connections. If needed,
the position of the heater can be fine-tuned by using the adjustable legs.
The legs must be opened by at least 30 mm. Observe the safety distances
between the heater and any inflammable material in accordance with
table 4.4 on page 7.
4) Place the heater on the floor and adjust the legs so that the heater stands
straight.
Note! Remove all plastic film before using the heater.
3. Heater assembly and installation

Installation and Operating Instructions Tahko
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Stacking the stones
Note! Use conventional sauna heater stones with rough cutting surfaces. Suitable stone materials
include peridotite, olivine diabase, and olivine. The use of ceramic “stones” and soft soapstone objects
is forbidden. It may damage the heating resistors.
The recommended size of the stone for the Tahko heaters 6,6 kW and 9,0 kW is Ø 5-10 cm (4 boxes á
20 kg). The recommended sizes for the stones for the Tahko 10,5 kW heater are Ø 5-10 cm (5 boxes á
20 kg) and Ø 10-15 cm (2 boxes á 20 kg). Place the bigger stones on the bottom of the heater and in the
middle of the the resistances to ensure a sufficient air circulation.
Rinse any dust off of the heater stones before stacking them in the heater. Use protective gloves.
Stack the stones so that the resistors remain upright and straight. Do not bend the resistors so that
they are in contact with the metal structures of the heater. You want to stack the stones along the
heater’s outer frame as tightly as possible and leave more space between the inner stones.
A wall of tightly stacked stones prevents thermal radiation from overheating the materials around the
heater.
The more loosely stacked inner stones let air flow through the heater, heating the stones and,
subsequently, the sauna room effectively.
Stacking the heater stones
1) Place the stones into the stone compartment carefully – do not drop them. Do not wedge stones
tightly between the resistors.
2) Begin stacking the stones from the centre, on the inside of the resistors.
3) When stacking stones on the inside of the resistors, ensure that the stones are not stacked too
tightly. Stacking them too tightly will cause the resistors to bend and touch each other or the heater
frame.
4) Do not place any objects or devices in or near the heater’s stone compartment which would alter
the air flow through the heater.
5) An exposed, hot resistor may cause materials even outside the heater’s safety distances to become
dangerously hot. Note! Ensure that the resistors do not touch the heater’s frame anywhere. There
must always be a stone between a resistor and the frame.
Note! Do not remove the bands around the resistors. If there are two bands, one of them is located at
approximately 20 cm from the bottom and another approximately 10–15 cm from the top. These keep
the resistors apart from each other and prevent premature deterioration.
Do not make a heap of stones on top of the heater!
Do not use the heater without the stones!
Dents caused by the user or others are not covered by Mondex’s warranty or other product liability.
When stacking the stones, be careful not to dent the heater’s metal surfaces to avoid damaging them.
For more information on the warranty and replacing stones, see page 17.

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4. Technical specifications
Heater Tahko 6.6 Tahko 9.0 Tahko 10.5
Power kW 6.6 9.0 10.5
Voltage 400 V 3N 400 V 3N 400 V 3N
Connecting cable 5 x 1,5 mm² 5 x 2,5 mm² 5 x 2,5 mm²
Fuse 3 x 10 A 3 x 16 A 3 x 16 A
Sauna size 6–9 m38–15 m312–22 m3
Table 4.1
Amount of stones
Type Stone amount (kg)
Tahko 6.6 80
Tahko 9.0 80
Tahko 10.5 140
Table 4.3
Heater dimensions (mm)
Type Diameter Height
Tahko 6.6 320 850
Tahko 9.0 320 850
Tahko 10.5 370 1100
Table 4.2

Installation and Operating Instructions Tahko
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Minimum distances to inflammable material (mm)
D
Table 4.4 Minimum distances to inflammable material (mm)
Type A B C D Volume
Tahko 6.6 100 100 770 1900 6–9 m³
Tahko 9.0 120 120 770 1900 8-15 m³
Tahko 10.5 120 120 900 2000 12-22 m³
AA B B
C

Installation and Operating Instructions Tahko
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5. General instructions for users of Tahko heaters
6. Things to keep in mind when using the heater
First heating
During the first heating, the resistors may emit fumes. Therefore, ensure that the room is properly
ventilated.
Sauna room
Always check the sauna room before switching the heater on! Always make sure that the timer has
switched the power off after the set time period!
Temperature control
The temperature is adjusted by means of either a mechanical thermostat (see page 10: M types) or the
control panel (see page 14: E2 types). The actual heating time depends on the dimensions, structure
and thermal insulation of the sauna. The temperature in the sauna room can be maintained at the
desired level with the thermostat. If the temperature of the sauna room becomes dangerously high for
any reason, the overheating protector will switch the heater’s power off. The cause of overheating must
always be investigated. The power can be switched on again by pressing the overheating protector
reset button (see page 10: M types and page 14: E2 types).
Heating time
An excessive heating time consumes energy and does not improve the steaming properties. The best
steam is achieved by keeping the sauna’s heating time relatively short, at about 30–60 min., according
to the size of the sauna and the heater’s power. The size of the sauna, the glass door, windows, or
materials used may require a longer heating time.
Water thrown onto the heater
We recommend using hand warm water. The water should be fresh household water. Throwing the
water onto the heater sides / lower stones generates softer steam. If you want steam that feels hotter
and more intense, pour plenty of warm water on top of the heater all at once. Do not use sea water or
chlorinated water.
Note
Electrical connections may only be made by an electrician with a valid installation authorisation
according to the current regulations. The Tahko electric heater is suitable for use in a family sauna,
one (1) heater per sauna room. Retain the installation and operating instructions for further reference.
Installation cable
Use rubber cable H07RN-F as a connection cable.
Additional connection options
Control of electric heating with the heater: The electric heating control cable is brought directly
to the heater’s junction box and further to the heater’s terminal block with a rubber cable that is
dimensionally identical to the incoming cable.
NOTE! Failure to observe the connection instructions may cause a fire hazard!
NOTE! Remove all plastic film before using the heater!

Installation and Operating Instructions Tahko
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Heating control
Indicator “Heater on”
7. Wiring diagram M type
Sauna room structure
The sauna and its ceiling, in particular, should have good thermal insulation, as heat tends to escape
through the ceiling. Due to the moisture, we recommend that you use aluminium paper. The size of the
heater should be selected according to the size of the sauna (in cubic metres). In addition to calculating
the power need for the regular sauna structure (glass wool–foil–wood), the following should be taken
into consideration.
If the sauna has any uninsulated wood, tile or concrete surfaces or the walls are made of logs, the
heater power needs to be increased. For every uninsulated square metre, the heater power need
increases by the same amount as if increasing the space volume by 1.2 m3 and on timber surfaces by
1.5 m3. The factor for glass surfaces (glass walls, doors and uninsulated stone surfaces) is also 1.2 m3
per square metre. In borderline cases, you should choose a heater with higher power.
The sauna needs efficient ventilation for a good oxygen level and a sufficient amount of fresh air.
The air in the sauna needs to change at least 6 times per hour. For a sauna with an electric heater,
mechanical ventilation is the most convenient ventilation method. The supply air should be provided
through an inlet located 500 mm, at a minimum, above the heater, either on the wall or in the ceiling.
NOTE: the distance of an undirected inlet air valve from the temperature sensor must be at least 1,000
mm, while the distance of an inlet air valve directed away from the sensor must be at least 500 mm.
The exhaust valve should be placed on the opposite wall, as far away from the heater and as close to
the floor level as possible. It is highly recommendable to install an exhaust air valve in the ceiling as
well for an easier removal of moisture after sauna sessions.
For more information, refer to the construction instructions and building regulations.

Installation and Operating Instructions Tahko
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The time switch (4+8 h) is also the heater’s main switch. After a set time, the time switch automatically
switches the heater off. With the timer function, the heater can be set to switch on in 1–8 hours. The
maximum warm-up time is 4 hours.
For example:
If you want the sauna to be ready as soon as possible, set the time switch between 1 and 4. The
heater switches on immediately and begins to warm up. Set the desired temperature by turning the
thermostat.
If you want the sauna to be ready in three hours, turn the timer to 2 on the time switch scale of 1–8.
The timer starts and the power will be switched on and the heater will start warming up after two
hours. When the power has been switched on, the heater will remain on for a maximum of 4 hours.
After that, the power will be switched off automatically. You can switch the power off sooner by turning
the time switch to zero (0).
Always make sure that the time switch has switched the power off after the set time period!
8. Time switch and thermostat operation M type
Time switch
Overheat protector reset
switch
Thermostat
Additional connection options
Connecting a signal light outside the sauna room
The connection cable used should be, for example, the H07RN-F cable with a cross-sectional area the
same as that of the connection cable.
Control of electric heating with the heater
The electric heating control cable is brought directly to the heater’s junction box and further to the
heater’s terminal block with a rubber cable that is dimensionally identical to the incoming cable.

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9. Installation instructions E2 type
Supply cable 5 x 1.5 mm2 / 5 x 2.5 mm2
Sensor
Fuse
box
Controller
Sauna
Changing
room
Utility
room
Heater
Controller
max. 99 cm
The controller must be placed at a minimum distance of
1 m from the heater
min. 1 m
10 cm
Sensor
on the
wall
10 cm
Sensor on
the ceiling

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Installation of external control and sensor
The type E2 heater package includes:
Controller
The temperature sensor can be placed either on
the wall or on the ceiling. It must be installed in a
place where it cannot be affected by the inlet air.
On the wall, place the sensor 10 cm from the
ceiling vertically at the centreline of the heater
(compare sketch on page 11).
On the ceiling, place the sensor 10 cm outside
the circumference of the heater (compare sketch
on page 11).
Place the reinforcing plate between the wall/box
and the plastic clip.
The plastic clip is either mounted to the wall
using three screws or affixed to the bottom of
the mounting box. The plastic clip is covered first
with a cover plate and finally with the control
panel. The length of the sensor cable is 10 m.
Cut the excess wire and connect the other
end to the heater. When installing the control
panel, make sure that the cables do not become
detached or bend.
Temperature sensor
Control panel
Reinforcing plate
Plastic clip
Cover plate

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10. Wiring diagram E2 type
OVERHEATING PROTECTOR
RLY1, RLY3, RLY5 RLY2, RLY4, RLY6
N
L1
L2
L3
P2
PE F2/5A
Controller card wiring, heater Controller card wiring, controller
N N L1 L2 L3 P2
1 White
2 Brown
3 Green
4 Yellow
5 Grey
6 Pink
Display:
1 Brown
2 White
3 Blue
4 Yellow
Sensor:
1 White 2 Brown 3 Green 4 Yellow 5 Grey 6 Pink
Heater:
Temperature
sensor
1 Brown 2 White 3 Blue 4 Yellow
Note! The terminal
screws must face
the wall.

Installation and Operating Instructions Tahko
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11. Heater control and operation, E2 type
DOWN
ON/OFF
UP
MENU
Switching on the heater
The heater is switched on by pressing the
ON/OFF button.
If three lines appear on the display, the buttons
are locked.
The buttons can be unlocked by
pressing the ON/OFF and MENU
buttons simultaneously until all LED segments
on the display are lit (as shown in the picture).
The heater is switched on by pressing
again the ON/OFF button.
Starting the heating process
When the heater is switched on, the duration of
heating last used is displayed (the default value
is 2 hours).
The duration of heating can be
changed by using the UP and DOWN
buttons, either by repeatedly pressing them
briefly or by keeping them depressed longer. The
time will change in 30-minute increments.
The target temperature last used can be
displayed by pressing the MENU button.
The temperature can be changed
by using the UP and DOWN buttons,
either by repeatedly pressing them briefly or by
keeping them depressed longer.
Timing of the heating process
The timing setting is displayed by pressing
again the MENU button.
The right-hand decimal point on the display is
lit as an indication of the fact that the timing
setting is displayed.
The setting can be changed by using
the UP and DOWN buttons, either by
repeatedly pressing them briefly or by keeping
them depressed longer. The time will first
change in 30-minute increments, and after ten
hours, in one-hour increments.
If the timing has been set and the ON/OFF
button is pressed, the timing will start first
and only after that the actual heating process.
During the timing, the right-hand decimal point
on the display is blinking as an indication of the
timing being in progress.
The timing setting can be changed
during the timing process by using
the UP and DOWN buttons, either by repeatedly
pressing them briefly or by keeping them
depressed longer.
If the timing setting is changed to zero or
the ON/OFF button is pressed during the
timing process, the timing process ends and the
heating process starts immediately.
Starting the heating
The duration of heating is displayed again
by pressing the MENU button one more
time. You can now start the heating by
pressing the ON/OFF button. The current
temperature will be displayed, and the right-hand
decimal point on the display is lit as an indication
of the heating process being in progress.

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The target temperature can be
adjusted by using the UP and DOWN
buttons. When the target temperature has been
adjusted, the current temperature will again be
displayed after a while. The remaining heating
time is displayed by pressing the MENU
button during the heating process.
The duration of heating can now be
changed by using the UP and DOWN
buttons, and the current temperature will be
displayed when the change has been made. If
the duration of heating is changed to zero, the
heating stops immediately.
Stopping the heating or timing process
The heater can be turned off by pressing
the ON/OFF button for a while during the
heating or timing process or any other
state.
Quick start of the heating process
The heating process can be started quickly
by pressing the MENU button. That sets
the duration of heating to two hours and the
target temperature to the value last used (the
default value is 70 °C).
If three lines appear on the display,
the buttons are locked. The buttons
can be unlocked by pressing the ON/OFF and
MENU buttons simultaneously until all LED
segments on the display are lit (as shown in the
picture).
Parameter Abbreviation Value range Default value
Button locking --- on/off ON
Error code Meaning
E01 The overheating protector has tripped
E02 The thermal sensor is out of order
E03 The thermal sensor is not connected
Error codes
When a known fault situation arises, an error code is displayed. It has one of the following meanings:
The heating process can be started by
pressing again the MENU button.
Parental control
The heater has a menu for separately set
parameters.
You can enter the menu by pressing
the MENU and ON/OFF buttons
simultaneously for a while.The abbreviation of
the first parameter will be displayed.
The current value of the parameter can be
displayed by pressing the MENU button.
You can change the parameter value
by using the UP and DOWN buttons.
The chosen parameter value can be saved
by pressing the MENU button so that the
abbreviation of the parameter is again displayed.
You can leave the menu by pressing the
ON/OFF button. This will also switch the
heater off.

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12. Heater control and operation, O type (without controller)
Using the heater
Type O heaters are operated from a separate control unit. Read the operating instructions delivered
with the control unit.
Sauna room
Do not place the inlet air valve so that the air flow cools the temperature sensor (for installation
instructions of the temperature sensor, see the instructions for the control unit)!
Overheating protector
Installation and resetting of the overheating protector, type O: See the installation instructions for the
control unit.
Wiring diagram

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13. Troubleshooting
Heater does not warm up
Check the heater fuses at the fuse box
Is the power on?
Check that all three heating resistors are glowing then the heater is on
Has the overheating protector tripped?
> M type: This is reset by pressing the overheating protector reset switch powerfully with a sharp
object until a click is heard. > Type E2: This is reset by pressing the button in the sensor box until a
click is heard. The cause of overheating must always be determined before the heater is switched on
again! If necessary, contact the dealer or manufacturer.
Warnings
- Due to a risk of fire, do not use the sauna to dry clothes or laundry.
- Exercise caution with a hot heater, since the heater stones and metal parts become very hot and can
cause burns.
- The water steam rising from the heater is hot and can cause burns.
- Children, disabled and ill persons who are using the sauna should be supervised.
- Benches and floors may be slippery, therefore move in the sauna with caution.
- Do not go to a hot sauna under the influence of narcotic substances (alcohol, drugs, narcotics, etc.)
Warranty
For heaters and control units in private use, the warranty is two (2) years. In commercial/professional use,
the warranty is three (3) months. Commercial use refers to facilities in which the heater is in use on a
continuous basis, such as fitness centres, swimming pools, housing companies etc. It is not recommended
that the heater is on for longer than six (6) hours at a time. Retain the sales receipt or warranty card. The
warranty does not cover external or internal mechanical damage caused by, for example, the impacts of
stones or the heater falling over. The warranty also does not cover defects caused by acts of nature, such
as lighting, or damage caused by overvoltage. Please also see chapter “Changing the heater stones”.
Removing or re-stacking of heater stones are not covered by the warranty in a potential warranty
maintenance. The manufacturer will not compensate the buyer for expenses incurred by a product defect
or malfunction, loss caused by disruption of business operations, or any other direct or indirect damage.
For more detailed warranty terms and conditions, please see www.mondex.fi/en/product-support/.
Maintenance and spare parts
In case of a fault that cannot be solved, please contact the store where you purchased the heater or
email info@mondex.fi. Spare parts can be purchased from Mondex distributors and the manufacturer.
When purchasing spare parts, please refer to the name, power, serial number and manufacturing date
of the heater to ensure you receive the correct parts.
Natural stone as material
Small pebbles or pieces may come off the natural stone used in the heater. As this is not a failure of
the organic material but a natural feature that cannot be predicted at the time of manufacturing the
product, the manufacturer is not responsible for any damage.
Changing the heater stones
Re-stack the heater stones and replace any eroded stones annually, more often if used intensively
(every three months in commercial/professional use). The good condition and proper, spacious
stacking of the stones around the resistors inside the heater ensure a sufficient air flow between the
resistors. If this is not done annually, proper air flow may be obstructed and the resistors may fail
prematurely, and that is not covered by the warranty.

Heater maintenance history
Date Action
We recommend changing the heater stones at one-year intervals. Change them more regularly if the
heater is used often.
Premec Oy
Kettukallionkatu 4
84100 Ylivieska,
Finland
info@mondex.fi
www.mondex.fi Technical support: info@mondex.fi