(April, 2013)
DRH Series GEN1 Ultrasonic Humidifi er Installation, Operation & Maintenance Manual
Failure Cause
Checking
Remedy
No mist is
generated.
Water supply
control system
Water supply fl oat
switch (FS1) is faulty.
If there is no continu-
ity, replace the switch.
‡
Water supply fl oat
switch sticking.
Drain the water tank,
remove the printed circuit
board terminal (X3) and
test the continuity of the
fl oat switch.
Water supply sole-
noid valve is faulty.
No water supply is pro-
vided even if the water tank is
drained and voltage between
terminals X2-1 & X2-2 on the
printed circuit board is 24 VDC.
Replace the
solenoid valve.
With the water tank fi lled
with water, remove the
wire from terminal (X3)
on the printed wiring
board and check conti-
nuity of fl oat switch.
If there is no continu-
ity, replace the switch.
Float switch for low
water level is faulty.
‡
Float switch for
low water level is
sticking.
Other
‡
Water supply fl oat
switch arm sticking.
Correct
terminations.
If the water level in the tank
is up to the overfl ow pipe,
remove the wire from ter-
minal (X3) on the printed
circuit board and ensure
there is no continuity on
the fl oat switch.
Amount of mist
is too low.
Water supply fl oat
switch is faulty.
Water supply
system
overfl owing.
Water supply
solenoid valve is
faulty.
Overfl owing occurs even
after power is turned off.
4) Consumable parts
Fan lead wires are
loose or disconnected
from the terminals.
Clean the switch. If
operation is not re-
stored, replace switch.
Open the electrical
section and check the
lead wire connecting
terminals.
Replace the
solenoid valve.
If there is continuity,
replace the switch.
Remarks:
If the humidifi er is operated for a long time with a deteriorated transducer, the nebulizer print plate may fail. The transducers
should be replaced using the estimated lifetime of 10,000 to 15,000 hours as the point of reference.
If the cause cannot be located through the above checking, please contact
STULZ
Product Support.
If the humidifi cation system is supplied with a water conductivity sensor (optional), ensure the sensor is operating properly
and that the supply water is within the recommended guidelines for mineral content.
3) If the cause cannot be located through the above checking, parts may faulty. Check the
interior of the humidifi er.
Clean the switch. If
operation is not re-
stored, replace switch.
Clean the switch.
If operation is not
restored, replace
switch.
The life is about 10,000 to
15,000 hours of humidifi er
operation.
No mist output,
or mist output is
too low.
Deterioration of transducer due
to aging.
Replace the transducer.
Failure Cause
Checking
Remedy
4-7