Fault messages

The tables below show potential faults and their causes. Column 3 Ackn. indicates whether or not the fault must be acknowledged after it has been eliminated.

Fault / Failure of

Message/Possible cause

Ackn.

Supply air
fan

Supply air fan fault

Cable break

Fan defective

M

Exhaust air
fan

Exhaust air fan fault

Cable break

Fan defective

M

Communication with main control unit (touchscreen control unit)

Fault in communication with main control unit

Cable break

Main control unit (RLS T2 WS, RLS G1 WS) defective

Wiring incorrect

A

Sensor: T-outside air upstream of EHE

Temperature sensor fault, upstream of earth heat exchanger (EHE)

Cable break

Temperature outside measuring range

A

Sensor: T air inlet, unit

Unit inlet temperature sensor fault

Cable break

Temperature outside measuring range

A

Sensor: T outgoing air

Outgoing air temperature sensor fault

Cable break

Temperature outside measuring range

A

Sensor: T supply air

Supply air temperature sensor fault

Cable break

Temperature outside measuring range

A

Sensor: T room external

External room temp. sensor fault

Cable break

Temperature outside measuring range

A

Sensor: T room control unit

Temperature sensor control unit fault

Cable break

Temperature outside measuring range

Main control unit (RLS T2 WS, RLS G1 WS) defective

A

Sensor: T room bus

Temperature sensor KNX fault

No data telegram for room temperature in the last 15 minutes

A

System memory

System memory fault

Checksum error of stored parameter, load commissioning data

M

System bus

System bus fault

Internal error, call in a trained specialist

A

Combi sensor (exhaust air humidity/temperature)

Humidity/temperature sensor exhaust air fault

Cable break

Humidity/temperature outside measuring range

A

Additional circuit board ZP1

ZP 1 communication fault

Cable break

ZP1 defective

Incorrect DIP switch setting on ZP 1

A

Additional circuit board ZP2

ZP 2 communication fault

Cable break

ZP 2 defective

Incorrect DIP switch setting on ZP 2

A

Bypass

Bypass fault

Motor defective

Foreign body blocks mechanics

M

Supply air temperature too cold

Temperature of supply air too cold

Heat exchanger iced up

Preheating register defective

A

Exhaust air temperature too cold

Temperature of exhaust air too cold

Exhaust air in unit too cold, apartment cooled

A

Frost protection

Frost protection fault

Cable break

Heating module defective

Temperature switch on the heat register defective

M

Zone shutter

Shutter fault

Motor defective

Foreign body blocks mechanics

M

External pre-heating

External pre-heating fault, external pre-heating defective

M

Pressure constancy setpoint not reached

Fault pressure constancy, setpoint is not reached

M