303.14701 - Sears/ Kenmore Central Humidifier

303.14701
Owners Manual
Installation - Humidistat

Installation

HUMIDISTAT

The humidistat is designed to mount on the return air plenum of your furnace or on an interior wall of the home. The return air plenum, however, is the preferred location for sensing the average humidity throughout your home and is the location covered by installation steps 1 through 11. (If you decide on the wall mount location, the humidistat control unit must be removed and mounted to the opposite side of the plastic back plate so it will be housed inside of the plastic cover - omit shaft extension - purchase additional low voltage wire, and run wire inside of wall to exit hole within the lower opening of the back plate.)

NOTE: The humidistat as supplied is assembled for return air plenum installation (Fig. 16)

Fig 16

RETURN AIR PLENUM MOUNT

1. LOCATE THE HUMIDISTAT on the return air plenum (Fig. 15). DO NOT install humidistat on supply air plenum. HUMIDISTAT MUST BE MOUNTED AT LEAST 6" UPSTREAM FROM FLEXIBLE HOSE (OR HUMIDIFIER IS HUMIDIFIER INSTALLED ON RETURN AIR PLENUM).

Fig 15

2. HUMIDISTAT MOUNTS IN A HORIZONTAL POSITION. Peel paper backing from template and paste it on return air plenum where humidistat is to be mounted. Keep level.

3. Drill 1/8" holes for the four mounting screws as shown on the template.

4. Cut out center portion of template within solid lines.

5. After removing paper backing from gasket, apply gasket around return air plenum opening as indicated on template. (Fig. 16)

6. Using low voltage wire supplied, connect spade terminals to solenoid valve on top of humidifier.

7. Position and support wire to humidistat location. Separate wire. Cut only one wire, strip ends.

8. Feed wires through opening in humidistat back plate and attach to screws terminals. Mount humidistat on return air plenum using (4) #8 screws provided. INstall shaft extension, cover and knob (Fig. 16).

CONTROL CIRCUIT: For proper operation and water conservation, this humidifier must be wired so it will operate only when the furnace blower is running and the humidistat calls for additional humidity. Two methods are shown (Fig. 17 and Fig. 18):

Fig 17: WIRING INTO FURNACE - FOR ANY FORCED AIR FURNACE WITH SINGLE SPEED 120 VAC BLOWER ONLY.

Fig 17

CAUTION: Do not use this method with multi- speed blowers other than 120 VAC.

Fig. 18: WIRING EXTERNAL TO FURNACE - FOR ANY FORCED AIR FURNACE INCLUDING FURNACE WITH OTHER THAN 120 VAC BLOWER MOTOR OR FURNACE WITH MULTI-SPEED BLOWER MOTOR.

Fig 18

NOTE: Some furnaces are equipped with accessory terminals that can be used for the humidifier. In this case, consult the furnace manufacturer's recommendations for wiring.

9. Turn off electricity at fuse box. Using (two) wire nuts and conduit nut supplied, install 24 VAC transformer to 120 VAC supply junction box following the control circuit selected so the transformer will be powered only when the furnace blower is running. Do not use existing transformer on furnace.

10. Connect spade terminals of low voltage wire to spade terminals of transformer.

11. Turn on electricity and test operation by observing if water is flowing to drain while furnace is running and humidistat is set to 'test' position.

NOTE: Wiring must conform to local codes.

12. Attach 'Operating Instructions Label' to return air plenum next to the humidistat. Peel off paper backing and stick label in desired location.

 

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