HomeMatic IP HmIP-eTRV-B-2 Installations- Und Bedienungsanleitung Seite 36

Troubleshooting
Once the batteries have been inserted,
the radiator thermostat will perform a
self-test and an adjustment run, if re-
quired (approx. 2 seconds). Afterwards,
initialisation is carried out. The LED test
display will indicate that initialisation
is complete by lighting up orange and
green.
10 Troubleshooting
10.1 Weak batteries
Provided that the voltage value permits
it, the radiator thermostat will remain
ready for operation even if the battery
voltage is low. Depending on the par-
ticular load, it may be possible to send
transmissions again repeatedly once
the batteries have been allowed a brief
recovery period.
If the voltage drops too far during
transmission, the empty battery symbol
( ) and the corresponding error code
will be displayed on the device,
„10.4 Error codes and flashing sequenc-
es" on page 37). In this case, replace
the empty batteries with two new ones
(see „9 Changing the batteries" on page
35).
10.2 Command not confirmed
If at least one receiver does not con-
firm a command, the LED (D) lights
up red at the end of the failed trans-
mission process. The reason for the
failed transmission may be radio inter-
ference, (see „13 General information
about radio operation" on page
This may be caused by the following:
• Receiver cannot be reached.
• Receiver is unable to execute the
command (load failure, mechanical
blockade, etc.).
• Receiver is faulty.
10.3 Duty cycle
The duty cycle is a legally regulated
limit of the transmission time of de-
vices in the 868 MHz range. The aim
of this regulation is to safeguard the
operation of all devices working in the
868 MHz range.
In the 868 MHz frequency range we
use, the maximum transmission time of
any device is 1% of an hour (i.e. 36 sec-
onds in an hour). Devices must cease
transmission when they reach the 1%
limit until this time restriction comes to
an end. Homematic IP devices are de-
signed and produced with 100% con-
formity to this regulation.
During normal operation, the duty
cycle is not usually reached. However,
repeated and radio-intensive pairing
processes mean that it may be reached
(see
in isolated instances during start-up
or initial installation of a system. If the
duty cycle is exceeded, this is indicated
by three slow flashes of the device LED,
and may manifest itself in the device
temporarily working incorrectly. The
device starts working correctly again
after a short period (max. 1 hour).
39).
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