5 Troubleshooting
5.1 General faults in the power supply
Error characteristics
Cause of error
Elimination of error
Nothing is shown on the
display
General power failure
No power to the controller
Main switch is turned off
FI-protective circuit breaker,
power line protection or SPS
power line protection tripped
Turn on the main switch
Switch on the protective circuit
breaker
5.1.1 Behaviour of system after a power failure
When the power supply has been restored, the boiler returns to the previous mode
and is controlled according to the specified program.
❒ After a power failure, check whether the STL (high-limit thermostat) has tripped.
❒ Keep the doors of the boiler closed during and after the power failure, at least until
the induced draught fan automatically starts up again.
5.2 Excessive temperature
The high-limit thermostat (STL) shuts down the boiler when it reaches a temperature
of 95 - 100°C. The pumps continue to run.
Once the temperature falls to below approx. 85°C, the STL can be reset mechanically.
❒ Unscrew the cap on the STL
❒ Unlock the STL by pressing with a screwdriver
5.3 Faults with fault message
If a fault has occurred and has not yet been cleared:
Troubleshooting
5
General faults in the power supply
Operating Instructions | B1300015_en
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