By reading the following DIY project you consent to the terms in the DIY disclaimer.

How To Install A Whole-home Humidifier

A whole-home humidifier helps improve home heating efficiency. Air with a higher humidity holds more heat energy than dry air. As a result, your furnace can produce warmer indoor conditions with less energy usage. You can learn how to install a whole-home humidifier if you feel comfortable with some light plumbing and electrical tasks.

Tools to Install a Whole-Home HumidifierHow to Install A Whole Home Humidifier

  • Felt-tip marker
  • Tape
  • Level
  • Power drill
  • Aviation snips
  • Saddle valve kit or pipe cutter
  • Screwdriver
  • Measuring tape

Step-by-Step Installation Instructions

  1. Shut off your furnace.
  2. Find the template for cutting the hole where the humidifier attaches to the forced air system.
  3. Tape the template in place.
  4. Check it with the level so that you don’t attach the unit crookedly.
  5. Mark the cutting lines with a felt-tip marker.
  6. Drill a hole in a corner of the box’s outline.
  7. Insert the tip of your aviation snips into the starter hole.
  8. Cut out the hole.
  9. Fit the humidifier’s mounting plate over the hole.
  10. Mark where to drill for the screws and drill the holes.
  11. Insert metal screws in the holes and tighten the mounting plate securely.
  12. Consult the manufacturer’s directions to learn where to place the humidistat. The control will likely go on the old air plenum, the box that connects the incoming ducts to the furnace.
  13. Take the marker and outline the hole for the humidistat.
  14. Drill a starter hole on the outline’s edge and then cut out the hole with the snips.
  15. Drill holes for the humidistat’s mounting plate.
  16. Secure the mounting plate with metal screws.
  17. If your humidifier’s controls need a step-down transformer, disconnect power to the appropriate circuit.
  18. Connect the transformer.
  19. Following the guidance in the manufacturer’s instructions, connect humidistat wiring.
  20. Complete wire connections by placing wire nuts over wires.
  21. Turn the wire nuts until tight.
  22. Find out if your local plumbing codes allow for the use of a saddle valve. If they don’t, you need to use a -fitting.
  23. Locate a water supply line near your humidifier unit. A hot water supply line is best.
  24. Shut off the water supply.
  25. For a saddle valve, position it over the supply pipe and pierce the line according to the saddle valve kit’s directions.
  26. Connect the humidifier water supply line to the saddle valve with a compression fitting.
  27. If codes require a T-fitting, cut the pipe with pipe cutters.
  28. Insert and connect the T-fitting.
  29. Connect the humidifier water supply line to the T-fitting.
  30. Some humidifiers have a bypass vent.
  31. If yours has one, use the provided template to mark a hole for a 6-inch vent pipe.
  32. Cut out the hole using a starter hole and tin snips.
  33. Secure a round collar on the hole with sheet metal screws.
  34. Measure and cut vent pipe to fit between the air inlet and collar using two elbows.
  35. Connect the piping to the collar and humidifier.
  36. Restore power and turn the water and furnace back on.

Ask Oliver to Install Your Whole-House Humidifier

If you’d rather not cut into your ducts or alter your plumbing and electrical, talk to Oliver. Our licensed technicians are experts at all furnace modifications. Let us help you improve your indoor comfort and heating efficiency at your home. Contact us today about humidifier installation.

Need help with this project?

If you do not have the time, tools, or experience necessary to complete the project, please contact the professionals at Oliver for help.

Contact us today at 1-888-810-2681 Get a Free Estimate