Siemens RDF302/VB Manual page 36

Fan overrun for electric
heater
Fan failure
Clean fan filter
reminder
Fault information
36 / 62
Siemens
Smart Infrastructure
When the electric heater is switched off, the fan overruns for 60 seconds
(parameter P54) to avoid over-temperature of the electric heater or prevent the
thermal cutout from responding.
In case of fan failure, the thermostat cannot protect the electric heater against
over-temperature. For this reason, the electric heater must feature a separate
safety device (thermal cutout).
The "Clean fan filter reminder" function counts the fan operating hours and displays
message "FIL " to remind the user to change / clean the fan filter as soon as the
threshold is reached. This does not impact the thermostat's operation, which
continues to run normally. This function can be set via parameter P62 (Service Filter).
The "Clean fan filter reminder" is reset when the operating mode is manually set to
Protection and back.
The 'Clean fan filter reminder' and error information (see 3.11.1) can be obtained
via Modbus object: Fault information
RDF302 Basic documentation CE1P3079en
2022-06-17