HM750A1000
33-00289—01
22
Inlet Valve Strainer Cleaning
Depending on the water quality, periodic cleaning of the
fill valve strainer may be required. This can be performed
without removing the valve from humidifier.
WARNING
Disconnect main power source before accessing
internal compartments.
The inside of the humidifier cabinet contains high
voltage components and wiring. Access should be
limited to authorized personnel.
1.
Turn off power to the humidifier with the external
disconnect.
2.
Close the supply water shut off valve.
3.
Using an adjustable wrench, remove the quick
connect fitting from the inlet valve. Have a cloth
available to absorb any residual water in the supply
line.
4.
Use a needle-nosed pliers to grip and remove the
inlet valve strainer.
5.
Clean the strainer with water and a plastic brush
(toothbrush), if necessary. Do not use soap or harsh
chemicals as these could be carried into the cylinder
when the humidifier is restarted.
6.
Press fit the strainer back into the inlet valve.
7.
Reconnect the quick connect fitting, tighten by
hand, then tighten ¼ turn with the adjustable
wrench.
8.
Turn on the humidifier water supply. Check for any
leaks.
9.
Turn on power at the external disconnect.
10.
Press the Power/Drain button for 1 second. The
humidifier will perform a short self-diagnostic
sequence before resuming normal operation.
CONTROL BOARD
REPLACEMENT
The control board controls all aspects of the humidifier’s
operation. In case of damage and/or failure, the control
board can be replaced. The control board will arrive with
factory settings and there is no need for any special
calibration other than selecting the correct mains voltage
(120 VAC or 240 VAC) supplied to the humidifier. This
product is shipped in anti-static packaging designed to
keep the electronics on the board safe from static shock.
CAUTION
Damage to Control Board
When handling the control board, ensure that you
are grounded. Static discharge can damage the
board, so handle it with care.
Opening Electrical Compartment
WARNING
Disconnect main power source before accessing
internal compartments.
The inside of the humidifier cabinet contains high
voltage components and wiring. Access should be
limited to authorized personnel.
To protect the user and the control board, the control board
is mounted in a red electrical compartment housing.
1.
Disconnect main power at the external disconnect.
2.
Using a flat screwdriver, turn the lock on the
humidifier’s front cover 90° counterclockwise to
release. Rotate the base of the cover outwards
6 inches, then lift upwards to remove.
3.
Use a flat screwdriver to loosen the retaining screw
on the red electrical compartment. Once free, pull
the cover straight out.
Removing the Control Board
1.
Use a Phillips screwdriver to release the control
board retaining screw. Keep the screw and plastic
washer (which protects the control board) for the
replacement control board.
2.
Pull the control board partially out of its housing.
Use a Phillips screwdriver to remove the primary
power wires from the terminal block (top-right of the
board). Then remove the spade terminals (cylinder
wires, high water sensor, ground wire) from the
board. Use a pliers, if necessary. As the control wires
are disconnected, label them to ensure they are
reconnected correctly. Finally, disconnect the
terminal block connection for the fill and drain
valves.
3.
With all wires removed, the control board will slide
out of its protective housing.
Installing the Control Board
1.
Set the control board VOLTAGE SELECTION jumper
to match the voltage supplied to the humidifier. Do
not assume the VOLTAGE SELECTION jumper on
the replacement board is correct! Always double
check the mains supply voltage.
2.
Slide the new control board partially into its housing
and reconnect all the wires. Refer to wiring diagram
on the unit for assistance. Ensure all spade
connections are press fitted completely on their
electrical tabs and the main power leads are well
tightened and not loose (loose connections lead to
heat buildup and a potential fire hazard).
3.
Once all wires and connections are made, slide the
control board completely into its protective housing.
4.
Ensuring the plastic washer is placed between the
screw head and the control board, secure the control
board with the retaining screw.
5.
Replace the electrical compartment cover.
6.
Replace the humidifier front cover, and turn the
locking screw 90° clockwise to secure it.
7.
Turn on the mains power to the unit at the
disconnect switch.
8.
Press the Power/Drain button for 1 second. The
humidifier will perform a short self-diagnostic
sequence before resuming normal operation.
