Dantherm HCH 5 Installation And Service Manual page 28

Fault finding instruction,
Inconvenience, con-
tinued
Abnormal noise
from the unit.
The unit is not
cooling suffi-
ciently.
Unstable opera-
tion, with a wide
variation of air
flow rates.
26
continued
Inconvenience
The installation has not been
done correctly. The air flow
channels might be partly
blocked.
The unit has not been balanced
correctly.
The outside air might be heated
up before entering the house.
The temperatures are exceeding
the established limits, which
must be met in order to achieve
cooling by means of bypass.
See the section "Set points and
control strategies" on page 15.
The bypass-damper is stuck or
the damper motor is defective.
The unit is probably set to Au-
tomatic Demand Mode which is
varying the air flow rate accord-
ing to the needs in the need of
the house and the indoor hu-
midity level.
There is no malfunction on the
unit.
Cause
Make sure that the ducts are led
correctly and that the air flows
are not blocked.
Balance the air flow rate as
shown in the section in the sec-
tion "How to balance the unit",
page 12
If necessary, move the inlet
grille to the north side of the
building.
Push the manual bypass button
and cooling will be active for
the next 6 hours.
Check the bypass module and
replace the damper motor if
necessary.
It is recommended to set the
unit in Manual Operation Mode
and choose the fan step which
meets the demands most opti-
mal (normally Fan Step 3).
It is not advisable to operate at
air flow rates beneath the de-
fined flow rate demanded in the
house, which have a reference
to national law regulations; oth-
erwise there might be a risk of
damage from damp and re-
duced air quality.
Action
Continued overleaf