Zehnder ComfoAir 550 Installationsanleitung Seite 90

This error will appear
when after 3 minutes of
switching on the preheater
element the temperature
increase of T1 is less
then 4ºC. This can also
happen when there is too
much cold air passing the
preheater element. In that
case reduce the airfl ow
and reset the unit (P74 on
1).
Yes
Is the
resistance of
Yes
the preheater element
cable infinite ?
Replace
preheater
element cable
Yes
Replace
preheater
element.
Yes
Disconnect the power from the
ComfoAir.
Remove the handles from the
ComfoAir.
Remove the filters from the
ComfoAir.
Release the front panel by
unscrewing the screws.
Slide the front panel upwards and
remove the front panel from the
ComfoAir.
Release the cover panel by
unscrewing the screws
Remove the cover panel.
Remove the screw from the
electronics carriage and pull the
electronics carriage carefully forwards.
Remove the cable of the preheater
elment from the control circuit
board.
Is the
resistance of
the preheater element
> 300 ?
No
Are the
connections at
the
preheater element
correct?
Reconnect the
preheater
Install all parts in
reverse order.
Reconnect the
power to the
ComfoAir.
Preheater element
does not heat
sufficiently.
P51 and
P57 set to
the correct
value?
Resistance of
Yes the NTC sensor
T1 correct?
Replace the
control
circuit board.
No
element.
A7
Is
No
Set P51 and P57 to
the correct value.
Reset the unit (P74 on 1)
No
No
Replace the
NTC sensor.
21 - EN