Honeywell Home HM750A1000 Instructions D'installation page 24

HM750A1000
TROUBLESHOOTING
CAUTION
High Voltage Hazard.
Be aware, when troubleshooting, that the
humidifier is powered by high voltage and
familiarity with both good practices and wiring of
the humidifier is recommended. Any
troubleshooting that requires opening the cabinet
should be done by qualified personnel.
CAUTION
Burn and Scalding Hazard.
Hot water or steam with a temperature above
120 °F (49 °C) can cause burns from scalding.
NOTE: Most humidifier faults are not caused by faulty
equipment but rather by improper installation. A
complete fault diagnosis always involves a
Symptom
Humidifier appears to have no
power, even when the
Power/Drain button is pressed
on.
Humidifier will not humidify or
not reaching humidification
(RH%) setpoint
Humidifier has faulted and red
Fault LED is flashing.
Distributor spitting out water
into duct
33-00289EF—05
Table 6. General troubleshooting.
Cause
Fuse blown
Incorrect voltage
Step down transformer not
outputting 24 VAC
Incorrect primary power
jumper
Humidistat terminals not
closed.
Low conductivity water
No airflow in duct
Software has detected an
abnormal condition
DUCT INSTALLATION: fill valve
failed open
REMOTE INSTALLATION:
condensate generation
thorough examination of the entire system. Often,
the steam hose connection has not been properly
executed, or the fault lies with the humidity
control system.
TROUBLESHOOTING REQUIREMENTS
• Ensure the installation meets the installation
requirements outlined in these instructions.
• Familiarize yourself with the operation of the humidifier
by reading these instructions in their entirety.
• The wiring diagram for your specific humidifier is
installed on the inside of the humidifier door. A generic
copy of the HM750 wiring diagram is also included at
the end of this chapter for reference purposes.
• When contacting your local representative or Resideo
for troubleshooting assistance, please ensure the serial
number and manufacturing date on the label at the left
side of the housing has been obtained for reference
purposes (Fig. 1).
Corrective Action(s)
Check on-board fuse located beside transformer.
Check voltage against specification label and correct.
Replace the circuit board.
Check that the on-board voltage selection jumper is
installed correctly. If 240 VAC power was supplied to a
unit where the voltage selection jumper was set to
120 VAC, the circuit board will need to be replaced.
Check voltage.
If operated on low conductivity water, it may take
several hours for the HM750 to reach full capacity.
This is normal. During this time, the humidifier will not
perform any drains and the conductivity of the water
in the cylinder will increase.
The unit will not operate on reverse osmosis or
deionized water. Ensure that tap water is used.
Note: New humidifier cylinders are supplied with a
salt tablet inside.
Check that the AP terminals on the control board are
wired correctly, and closing the 24 VAC chain.
Review fault-code label on the inside cover of the
HM750 or see Table 7 on page 25.
Check that the fill valve has not failed in the open
state. This would make water flow inside the cylinder
above the level of the high water sensor, to a
maximum of the fill cup overflow level. At this point,
water may carry over into the distributor nozzle and
"spit" into the duct.
Ensure the nozzle is oriented correctly and the steam
line is sloped correctly, as per the guidelines in these
installation instructions.
24