Emerson DE User Manual

The humidifier RUN/DRAIN switch is located in the unit low voltage compartment for most Deluxe 

models (in the humidifier assembly for models FH599, 600, 739, 740C). This switch should be in the 

RUN position when the humidifier is in normal operation; it should be in the DRAIN position when a 

manual drain for service is required. The electronic control board for the humidifier is located in the 

same area as the humidifier RUN/DRAIN switch. When the main unit is energized, power is available 

to the humidifier circuits.

See Step 5 of Operation in 7.5.2 - Steam Generating Humidifier for indications that a canister 

may need to be replaced. 
To replace the canister:
1. Turn off the humidifier by lowering the humidity setpoint below the ambient humidity level. 

Record the original setpoint.

2. Place the RUN/DRAIN switch in the DRAIN position to drain the water from the canister.
3. Return the RUN/DRAIN switch to the RUN position after the canister has drained.

4. Turn OFF the power at the main unit.
5. Remove the cover from the humidifier cabinet.

6. FOR ALL MODELS EXCEPT FH599C, 600C, 739C and 740C, refer to replacement instructions 

that accompany replacement kit 153315P1 and P2. 

7. For models FH599C, 600C, 739C and 740C, locate the power wires to the steam canister. Make 

note of the wiring configuration before removing any wires. Refer to schematic on unit. Slide the 

rubber boot back to expose the connections. Remove the three power wires and the canister full 

wires at terminals 1,2 and 3. Do not loosen the screws that secure the electrodes.

8. For all models, use a screwdriver to remove the hose clamps that secure the drain and overflow 

hoses from the canister ports.

9. Loosen the fill line compression fitting and remove the tube from the input canister port.
10. Loosen the steam outlet hose clamps and slide the steam hose away from the canister fitting. 

Release the canister clamp along the best of the canister.

To avoid a shock hazard, all power to the unit must be disconnected before proceeding with 

the canister replacement procedure.

The canister and steam hose may be hot! Allow time for the humidifier to cool before replacing 

parts.