How to: Install a Furnace Humidifier

Get better results heating your house with the addition of a funace humidifier. Here's what's involved and how to install a furnace humidifier with a list of the material and tools you need.

Step  8:   Install the drum and adjust water level

Fit the flat end of the drum shaft into the motor. The opposite end snaps into position in the center of the air collar.

Adjust the water level by altering the height of the float. The optimal level in the pan is about 3/4-in. from the top of the water pan. Open the main water valve and then the supply valve on the water pipe and adjust it to get a moderate water flow. Loosen the screw and adjust the float so it closes the automatic valve when the water level reaches 3/4-in. from the top of the pan. Then tighten the screw.

Step  9:   Install the humidistat and the transformer

This humidifier comes with a transformer that can be plugged into any electric outlet. The humidistat is a duct-mounted type. The return duct mounting allows for a better sensing of all the air returned to the furnace without being disturbed by a sudden increase in moisture level. Install the humidistat on a flat and vertical surface of the return duct about 6-in. from the top of the humidifier. Tape the humidistat template on the duct and mark and drill mounting holes. Cut an opening for the humidistat and push the connectors onto their terminals.

Fasten the humidistat to the duct and temporarily install the control knob. Wire the control to the motor and power supply according to the installation instructions provided by the manufacturer.

Step  10:   Start and adjust the humidifier

Plug in the transfomer and slowly turn the humidistat control knob to its maximum setting. You should hear a click and the drum should start turning slowly. Check that both ends of the water supply tubing are held firmly in place. Also check that the water level in the pan is at the correct level and that the float closes the automatic valve completely. Set the humidistat to a median value (40%) and make sure there's no leaks.

Illustrations courtesy of Hamilton Home Products, Inc.

Page 3 of 3
Back to Page 1


Format for Print