Fault diagnosis and rectification
Installation instructions geoTHERM 0020051574_04
107
11
11.6 Other
errors/malfunctions
Malfunction sign
Possible cause
Solution
The auxiliary heating system does not work
even though it has been enabled by the
controller (e. g. during the switch-off time
by the power supply operator (energy sup-
ply company switch-off time)), the heating
system or the DHW tank do not reach the
desired temperature.
The auxiliary heating system is connected
on a low-rate tariff and this tariff has just
been blocked by the power supply operator.
>
Check whether the auxiliary heating is
on a low-rate tariff and a power com-
pany blockage is in effect.
The auxiliary heating safety thermostat has
triggered.
>
Release the safety thermostat by press-
ing the pushbutton.
Possible causes if the thermostat trips again:
Air in the heating system. Blocked dirt filter
in the return of the heating system.
>
Bleeding heating circuit. Clean the
blocked dirt filters.
The heating pump has stopped or is running
too slowly.
>
Check the heating pump and replace
if necessary.
Noise in the heating circuit.
Air in the heating circuit.
>
Bleeding heating circuit.
Dirt in the heating circuit.
>
Flush the heating circuit.
Bivalent temperature incorrectly set.
>
Change the bivalent temperature
(
Menu A3
)
¬
Tab.
9.9
.
Pump output of the external heating pump
has dropped or pump is faulty.
>
Check functioning of the pump; replace
if necessary.
Traces of water under or next to the heat
pump.
The condensate drain is blocked.
>
Condensate inside the unit is collected
in the condensate pan and may be dis-
charged under the heat pump (not a
fault). Check the line insulation inside
the unit, and re-insulate if necessary in
order to reduce condensate formation.
Leaks in the heating circuit.
>
Check the heating circuit components
(pump, auxiliary heating system, pipes)
for leaks.
>
If necessary, retighten the screw cou-
plings and replace the seals.
Outside temperature indicates -60 ºC.
Outside temperature sensor not connected
or faulty.
>
Check outside temperature sensor.
Temperatures in the heating circuit too low
or too high.
Target room temperature not optimally set.
>
Change the target room temperature
(Menu
1,
¬ operating instructions
).
Night set back temperature not optimally
set.
>
Change the night set back temperature
(Menu
1,
¬ operating instructions
).
Heating curve not optimally set.
>
Change the heating curve (
Menu C2
)
¬
Tab.
9.6
11.5 Other errors/malfunctions
