27
Central Ventilation Units KWL EC 700/1400/2000 D Pro / WW
Installation and Operating Instructions
Fault
Unit behaviour
Problem
Solution
27 - Fault with pressure
sensor of supply air filter
Unit ventilates
Pressure sensor fault
Check whether the measuring device is damaged or
contaminated. Check the pressure hoses for consistency. If
necessary, replace the pressure sensor module.
28 - Fault with pressure
sensor of supply air fan
Unit does not operate
properly
Pressure sensor fault
Check whether the measuring device is damaged or
contaminated. Check the pressure hoses for consistency. If
necessary, replace the pressure sensor module.
29 - Fault with pressure
sensor of extract air filter
Unit does not operate
properly
Pressure sensor fault
Check whether the measuring device is damaged or
contaminated. Check the pressure hoses for consistency. If
necessary, replace the pressure sensor module.
30 - Fault with VAV pressure
sensor (supply air duct)
Unit does not operate
properly
Pressure sensor fault
Check whether the measuring device is damaged or
contaminated. Check the pressure hoses for consistency. If
necessary, replace the pressure sensor module.
30 - Fault with VAV-C4
pressure sensor (extract air
duct)
Unit does not operate
properly
Pressure sensor fault
Check whether the measuring device is damaged or
contaminated. Check the pressure hoses for consistency. If
necessary, replace the pressure sensor module.
32 - Air quality sensor fault
Unit ventilates
Air quality sensor malfun-
ction
Check whether the air quality sensor is correctly connected.
If necessary, check the functioning of the sensor (output
signal value).
33 - Humidity sensor fault
Unit ventilates
Air quality sensor malfun-
ction
Check whether the air quality sensor is correctly connected.
If necessary, check the functioning of the sensor (output
signal value).
34 - Fault with external tem-
perature sensor of BMS
Unit ventilates
BMS sensor fault or incor-
rect data
Check address and sensor value in BMS system. Check
functioning of BMS sensor.
50 - Supply air filter blocked
> 80 %
Unit ventilates
Filter blocked
Replace filter.
51 - Extract air filter blocked
> 80 %
Unit ventilates
Filter blocked
Replace filter.
70 - Hot water heater bat-
tery frost protection.
Unit ventilates
Water heat exchanger frost
protection is active
Automatic protection of water heater battery is active to
prevent damage by low temperatures. This function is auto-
matically ended as soon as the return temperature reaches
the target value.
71 - Water heater - wait for
the water temperature
Unit ventilates
Water temperature evaluati-
on active
Process ends automatically.
72 - Water heater - wait for
the supply air temperature
Unit ventilates
Supply air temperature
evaluation.
Process ends automatically.
73 - Free night cooling is
active.
Unit ventilates
Temperature evaluation for
the free night cooling
The preparation for the free night cooling is running. In this
respect, the start conditions for this function are evaluated.
The process ends automatically.
74 - Flow reduction, mini-
mum temperature in duct is
not reached
Unit works in restricted
mode
The unit tries to reach the
minimum temperature
Minimum supply air temperature is not reached. There is an
automatic output correction (supply air fan is turned down).
75 - Passive house pro-
tection
Unit does not operate
The unit works in such a
way that meets the passive
house specification
Minimum supply air temperature for the passive house requi-
rements has not been reached. Automatic process.
36 - Fault in B circuit board
Unit does not operate
The unit cannot operate the
peripherals connected to
the B circuit board
Communication with the B circuit board cannot be establis-
hed. Check communication cable between A and B circuit
boards. If necessary, replace B circuit board.
37 - Condensation tray
overflow
Unit does not operate
Water level in condensation
tray is too high
Check sensor connection. Check functioning of sensor and
check whether the unhindered drainage of the condensation
tray is possible.
