Scale Lights Of Control Box; Thermostat And Overheating Limiter; Thermostat; Overheating Limiter - Harvia AV-4 Instructions For Installation Manual

1.2.1 Scale Lights of Control Box

DIM LIGHT:
standby power of 250 W is switched on
•
BRIGHT LIGHT:
standby power + heater power are switched on
•
NO LIGHT:
neither the standby power nor the heater power
•
are switched on, or the thermostat has switched
off the currents to the resistors

1.3. Thermostat and Overheating Limiter

1.3.1. Thermostat

The thermostat controlling the warming up of the
heater's rock space is located under the control box
cover at the foot of the heater. The thermostat
switches off the currents to the heat resistors for a
while if the control value set on the thermostat is
exceeded. When the rock space has cooled enough,
the currents to the resistors are switched on again.
The thermostat is adjusted to the correct temperature
at the factory. The heater's thermostat prevents the
temperature of the rocks from exceeding approx.
+350°C. On standby, the temperature of the stones
does not reach the thermostat's switch-off
temperature and, therefore, the heater is continuously
on when the standby power is switched on. By keeping
the heater on standby, you can make sure that the
heater's stones are ready for bathing immediately after
you open the lid.
The heater power, switched on by the timer, may
gradually raise the temperature of the heater to the
level of the thermostat's switch-off temperature even
though the lid is open. As a result, the currents to the
resistors will be switched off. If the lid is closed, the
currents to the resistors will be switched off very
quickly. The currents will be switched off unnoticably,
because a timer-indicator light will stay on on the
display panel. By turning the timer to zero, you can
make sure that there is no light on the display panel;
ie, no currents flow to the resistors through the
thermostat.

1.3.2. Overheating Limiter

If the temperature of the heater rises too high for some
reason, the overheating limiter, connected to the thermostat,
will permanently switch off the currents to the resistors.
The overheating limiter can be reset to the position which
allows currents to flow through the thermostat only after
the heater has cooled. The thermostat has a reset button
to reset the overheating limiter. To reset the overheating
limiter, the reset button is pressed hard enough so that you
can hear a click. The pressing may require a force
corresponding to 7 kilograms. See figure 2.
Prior to pressing the button, the cause of the fault must
be found:
are the stones crumbled and pressed together?
•
has the heater been on for a long time while
•
unused?
has the heater been banged or shaken?
•

1.4. Piling of the Sauna Rocks

The sauna rocks for an electric heater should be 1
1/8
3 " (4–8 cm) in diameter. The heater rocks should be
solid blocks of rock specially intended for use in the heater.
Neither light, porous ceramic "rocks " of the same size
nor soft potstones should be used in the heater, because
they may cause the resistance temperature to rise too
high as a result of which the resistance may be broken.
4.
Rock dust should be washed off before piling the rocks.
The rocks are piled on the bottom of the heater's rock
space and the grate in between the heating elements
(resistors) so that the rocks support one another. The
rocks should not be piled too tightly to allow the air to
freely flow through the rock space. The weight of the
rocks should not lie on the heating elements. The rocks
should not be piled too tightly, so that air can flow through
the heater. See Figure 3. The rocks should be not wedged
between the heating elements. The resistors should neither
be in contact with the walls of the rock space nor touch
Figure 2. Resetting the overheating
limiter
Figure 3. Piling of the sauna rocks
one another. The rocks should completely cover the heating
elements. The entire rock space should be filled with rocks,
but there should be enough space for the lid to close
properly.
Note! When the rocks have been placed inside the heater,
the heater should be warmed up to remove moisture from
the rocks. See Point 1.5 "First Heating Time".
The guarantee does not cover any faults caused by the
use of rocks not recommended by the plant. Neither does
9/16 "– the guarantee cover any faults caused by disintegrated or
too small rocks blocking the heater ventilation.
No such objects or devices should be placed inside the
heater rock space or near the heater that could change
the amount or direction of the air flowing through the heater,
thus causing the resistance temperature to rise too high,
which may set the wall surfaces on fire!