Honeywell Honeywell Advanced Electrode Steam Humidifier HM750A1000 HM750A1000

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.

Power to the humidifier turned off with the external disconnect

Supply water shut off valve closed

Quick connect fitting removed from the inlet valve using an adjustable wrench

Inlet valve strainer removed using a needle-nosed pliers

Strainer cleaned with water and a plastic brush (toothbrush), without using soap or harsh chemicals

Strainer pressed back into the inlet valve

Quick connect fitting reconnected, tightened by hand, then tightened 1⁄4 turn with the adjustable wrench

Humidifier water supply turned on. No leaks detected

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.

Drain the cylinder by pressing the Power/Drain button on the front of the humidifier for 1 second. Let the humidifier drain until no more water is flowing out to drain (usually not more than 10 minutes). Following the drain cycle, the humidifier will switch off.

Close the supply water shut off valve.

Turn off power to the humidifier with the external disconnect.

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.

Disconnect the wiring to the solenoid.

Remove quick connect fitting from inlet valve.

Grip the inlet valve and pull forward as far as possible.

Inside the humidifier, bend the hose attached to the inlet valve.

Cylinder LED indicates replacement?

Strainer clean and free of debris?

Drain valve clean and free of scale/debris?

Drain valve functioning properly without leaks?

Hose connections clean and in good condition?

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.

Cleaned the drain valve before installing a new cylinder

Disconnected spade terminals from the drain valve

Held the hose connected to the drain valve and pulled forward while at the same time pressing on the drain valve locking tab to release the valve body from its mount

Disconnected the hose from the drain valve by pulling on the hose

Removed the solenoid from the drain valve using a Phillips screwdriver

Pulled the solenoid from the core

Unscrewed the core counterclockwise from the drain valve body using an adjustable wrench

Removed the core assembly (this includes the plunger and return spring) from the plastic drain valve body

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.

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.

Main power disconnected at the external disconnect?

Humidifier’s front cover unlocked and removed?

Retaining screw on the red electrical compartment loosened and cover removed?

Control board retaining screw released and control board partially pulled out of its housing?

Primary power wires and spade terminals removed from the board?

Terminal block connection for the fill and drain valves disconnected?

Control board VOLTAGE SELECTION jumper set to match the voltage supplied to the humidifier?