Honeywell HE360 Humidifier Wiring Diagram
HE360 control wiring
Humidifier, humidistat and air switch; the red and white wires of each bundle can be swapped.
Terminals and components · 5
- Red wires
- Valve
- Air switch
- Humidistat
- Outdoor sensor
How to connect it
- At the humidifier, connect the two red wires to the red and white wires of bundle 1.
- At the humidistat, connect the red and white wires of bundle 1 to R and C (polarity doesn't matter).
What to do
With the H8908 humidistat, the humidifier red wires are not used: insulate them.
How to connect it
- At the humidifier, connect the two yellow wires to the red and white wires of bundle 2.
- At the humidistat, the red wire of bundle 2 goes to the upper U terminal.
- The white wire of bundle 2 is wire-nutted to the white wire of bundle 3 (going to the pressure switch).
How to connect it
- At the humidifier, connect the black and white conductors of bundle 1 to the two yellow wires.
- At the humidistat, connect both black conductors to its two terminals and wire-nut the two white conductors.
Important
Use this wiring diagram, not the one supplied with the humidistat instructions.
H6062 terminals
Terminal Goes to R · C Red wires (constant 24 V AC) U (upper) Bundle 2 red (valve) U (lower) Bundle 3 red (pressure switch) S · S Outdoor sensor What it does
The H8908 is a two-terminal humidity control: its two black conductors are in series with the valve and the sail switch.
How to connect it
- At the humidistat, the red wire of bundle 3 goes to the lower U terminal.
- At the pressure switch, the red and white wires of bundle 3 go to C and NO. NC is not used.
Important
The furnace blower must be on to activate the humidifier.
How to connect it
At the sail switch, the black and white conductors of bundle 2 go to COM and NO. NC is not used. The humidistat and sail switch can be wired in any order.
How to connect it
Connect the two outdoor sensor wires to the S terminals.
About This Diagram
This diagram is redrawn from page 11 of the Honeywell HE360 Humidifier manual, and we offer it completely free and in English. We have also categorized it in the Humidifiers (HVAC & Water Heating) section on Diagramverse, and it has been rated by 1 user with an average rating of 5.0. If you have any specific questions about the Honeywell HE360 Humidifier Wiring Diagram, we suggest checking the Frequently Asked Questions (FAQs) section.
Printable Honeywell HE360 Wiring Diagrams
Wiring Instructions
Before you start
First, find out which variant of Honeywell HE360 you have. Current HE360A1075 and HE360D1075 packages come with an H6062 digital humidistat and an air pressure switch. For these, use the H6062 + pressure variant. Older HE360 installation kits came with an H8908 dial humidistat and a sail switch. For these, use H8908 + sail. The wiring is different: the H6062 needs constant 24 V AC on its R and C terminals, but the H8908 is just a contact in series with the valve. Wire from this HE360 drawing, not from the generic diagram packed with the humidistat.
Tools: screwdriver, wire stripper, drill, punch or awl, tin snips, level, gloves, safety glasses and a multimeter that reads AC voltage. Materials: 18 gauge two-strand thermostat wire and wire nuts (four are included). For the H6062 + pressure layout, plan on three two-strand bundles. Two run from the humidifier to the humidistat, and one runs from the humidistat to the pressure switch. Measure each run and leave extra wire at both ends.
The humidifier plugs into a 120 V, 60 Hz outlet and draws 0.7 A. If there's no outlet within reach of the cord, have a licensed electrician install one. That work usually needs a permit, so check with your local authority. Before you wire anything, unplug the humidifier and turn off the furnace or air handler at its circuit breaker.
Mount the components first. Mount the pressure switch vertically with its pressure connectors facing down. Run the supply duct tubing to the + port and the return duct tubing to the – port. Install the sail switch in the cold air return. Keep only the spring that matches the airflow direction, or remove both springs for horizontal airflow. Mount the humidistat on the return plenum at least 8 in. upstream of the humidifier, or on a wall in the living space.
Step-by-step wiring: H6062 + pressure
- Pull the three bundles and label them 1, 2 and 3 at both ends. Labeling prevents the most common mix-up: swapping the power bundle and the valve bundle.
- At the humidifier, splice the two red wires to the red and white conductors of bundle 1 with wire nuts.
- At the humidifier, splice the two yellow wires (solenoid valve) to the red and white conductors of bundle 2.
- At the humidistat, land bundle 1 on R and C. Either color can go on either terminal.
- Land the red conductor of bundle 2 on the upper U terminal.
- Join the white conductor of bundle 2 to the white conductor of bundle 3 with a wire nut. This splice carries the valve circuit on to the air switch.
- Land the red conductor of bundle 3 on the lower U terminal.
- At the pressure switch, connect the red and white conductors of bundle 3 to C and NO. Leave NC empty.
- If you use the optional outdoor sensor, wire it to the two S terminals.
Step-by-step wiring: H8908 + sail
- Run one two-strand cable from the humidifier to the humidistat and another from the humidistat to the sail switch. You can wire the humidistat and the sail switch in either order.
- At the humidifier, splice the black and white conductors to the two yellow wires. The red wires are not used. Cap each one separately so the bare ends can't touch anything.
- At the humidistat, connect both black conductors to its two terminals, and join the two white conductors with a wire nut.
- At the sail switch, connect black to COM and white to NO. Leave NC empty. Snap the cover on after wiring.
Whichever variant you have, tug each wire nut to make sure it holds, and tighten the terminal screws onto bare copper, not insulation. Secure the cable so it stays clear of hot flue pipes, sharp duct edges and the drain line.
Testing and start-up
- Before power-up, confirm the humidifier is level, the feed line has no kinks, the drain line slopes continuously down to the floor drain, and the internal hose is connected to the water distribution tray.
- Plug in the humidifier, turn the furnace breaker back on and open the water shut-off valve.
- H6062 + pressure only: measure across R and C. You should read about 24 V AC at all times, whether or not the blower is running.
- Turn the H6062 all the way up (Humidity Boost should appear), or set the H8908 to On. Then set the thermostat 10°F above room temperature so the furnace and blower start.
- With the blower running, you should hear the solenoid valve click, and water should flow out of the drain hose shortly after. With the blower off, the valve must stay closed even when the humidistat is calling.
- Check every water joint for leaks. Then return the thermostat and humidistat to comfortable settings for automatic operation.
Safety notes
- The cord and outlet carry 120 V. Unplug the humidifier, and shut off its water, before you remove the cover or touch the wiring.
- The control wiring is low-voltage 24 V AC, but it still matters. If the two red wires or R and C touch, they short the 24 V supply. If you put 24 V on the U terminals, you can damage the humidistat.
- Don't cut or drill into the A-coil, the wiring or any other air conditioning or electrical accessory. Wear gloves and safety glasses: cut duct edges are sharp.
- Keep wire nut splices dry and away from the solenoid valve and drain fittings. Respect the temperature limits: 32°F to 160°F around the humidifier, and -40°F to 190°F for the pressure switch.
- All wiring must comply with your local codes.
Troubleshooting
| Symptom | Probable Cause | What to Check |
|---|---|---|
| H6062 never calls for humidity and there's no 24 V at R and C | Humidifier unplugged, outlet dead, or a loose splice between the humidifier red wires and bundle 1 | Check the outlet for 120 V. Then measure across R and C. You should read about 24 V AC with the humidifier plugged in. If you don't, redo the red-wire wire nuts. |
| Humidistat goes dead or acts erratically as soon as it calls for humidity | Bundles 1 and 2 swapped at one end, so 24 V reaches the U terminals and the valve wires land on R and C | Follow your labels. At the humidifier, the red wires must go to bundle 1, and bundle 1 must land on R and C. The yellow wires go to bundle 2, which lands on the upper U. |
| Water runs down the drain even when the furnace blower is off | Air switch wired to NC instead of NO, or the switch bypassed or jumpered | Move the wire from NC to NO. With power off, check continuity between C (COM on the sail switch) and NO. It should be open with the blower off and closed with the blower running. |
| Blower is running and the humidistat is turned up, but the valve never clicks | Air switch not closing: pressure tubing reversed or loose, wrong sail switch spring, or a broken white-to-white splice | Confirm the supply tubing is on + and the return tubing is on –. Check that the sail moves freely and that only the correct spring is fitted. Measure for about 24 V AC across the yellow wires during a call. |
| Humidifier runs nonstop and ignores the humidistat setting | Humidistat contact bypassed, for example the bundle 2 red and bundle 3 red joined together instead of landing on upper U and lower U | Turn the humidistat to its lowest setting, unplug the humidifier and check that the two U wires are not joined anywhere else. Only the two white conductors should share a wire nut. |
| Older H8908 kit wired from the H6062 drawing and nothing works right | Wrong variant: the H8908 has no R, C or U terminals and doesn't use the red wires | Rewire to the H8908 + sail variant. Yellow wires go to the black and white conductors, the blacks go to the humidistat, the whites are joined, and the sail switch uses COM and NO. Cap the red wires separately. |
| Humidifier works sometimes, then stops for no clear reason | Loose wire nut, a strand broken at a terminal, or thin or damaged cable | Tug-test every splice and re-strip any nicked conductor. Use 18 gauge two-strand thermostat wire. Measure the yellow wires during a call: you should see a steady 24 V AC. |
| Turning the H6062 all the way up doesn't show Humidity Boost | Boost not enabled at setup, or very cold outdoor temperatures limiting humidity through the outdoor sensor | Check the boost setting in the H6062 setup. Confirm the outdoor sensor is on both S terminals and isn't shorted where it is mounted. |
| Valve clicks but no water reaches the drain | Problem on the water side, not the wiring: shut-off valve closed, saddle valve needle not backed out, or kinked tubing | Open the shut-off valve fully, check the feed tubing for kinks and remove the cover to see whether water reaches the distribution tray. |
| Furnace breaker trips or its fuse blows during the installation | A screw or drill bit hit wiring or an electrical accessory, or bare low-voltage conductors are touching metal | Turn off power and inspect the cut-outs and screw locations. Make sure no bare copper shows at any splice or terminal. Have an HVAC professional check any damaged furnace wiring. |
Frequently Asked Questions (FAQs)
How do I know whether I have the H6062 or the H8908 version?
Look at the humidistat that came with your HE360. Current packages (HE360A1075 and HE360D1075) include an H6062 digital humidistat with R, C, U, U, S and S terminals, plus an air pressure switch. Older installation kits included an H8908 dial humidistat with two terminals and a sail switch. Pick the matching variant in the diagram, because the two use different wires: only the H6062 uses the humidifier red wires for constant 24 V power.
Do I need a separate 24 V transformer for the HE360?
No, not for the standard H6062 setup. The humidifier plugs into a 120 V outlet and puts out 24 V AC on its red wires, which power the H6062 through R and C. The valve circuit runs on the yellow wires through the humidistat and the air switch. With the older H8908 kit, the red wires stay unused. If your setup doesn't match either variant, don't add a transformer on a guess: check the labels on your unit.
Does wire polarity matter on the HE360 control wiring?
No. You can swap the red and white conductors of any bundle, and R and C on the H6062 can take either wire. What does matter is which bundle goes where: the power bundle must land on R and C, the valve bundle on the upper U, and the air switch bundle on the lower U and the white splice. Label the bundles at both ends to keep them straight.
What wire should I use between the humidifier, humidistat and air switch?
Use 18 gauge two-strand thermostat wire for every control run. The H6062 layout needs three bundles: two from the humidifier to the humidistat and one from the humidistat to the pressure switch. The H8908 layout needs one run from the humidifier to the humidistat and one from the humidistat to the sail switch. Measure each route before cutting, and leave enough slack at both ends to strip the wires and make clean connections.
Can I leave out the pressure switch or sail switch?
No. The air switch is a safety interlock: it lets the solenoid valve open only while the furnace blower is moving air across the pad. Without it, the humidistat could run water whenever humidity is low, even with the furnace idle, which wastes water and soaks the pad with no airflow to evaporate it. Wire it to C or COM and NO, and leave NC empty.
Can I use a pressure switch instead of a sail switch, or the other way around?
Yes. Both do the same job, which is closing the valve circuit when the blower runs. The difference is in how you mount them and what the terminals are called. The pressure switch mounts vertically with its ports facing down and uses C and NO. The sail switch sits in the return duct and uses COM and NO. Follow the diagram variant for the humidistat you have, and use the matching terminal names at the switch.
How should I connect the pressure switch tubing?
Connect the supply duct tap to the + port and the return duct tap to the – port. You can also use only a supply tap on + or only a return tap on –, but connecting both gives the switch a clearer signal. Cut 3/4 in. holes within 10 feet of the switch and fit the rubber gaskets and elbows. Secure the tubing so it can't be knocked off, or the valve will stop opening.
Do I have to install the outdoor sensor?
No, the outdoor sensor is optional. If you use it, it connects to the two S terminals on the H6062, and the humidistat then automatically lowers its target as the weather gets colder to reduce window condensation. Without it, adjust the setting yourself: about 40 above 20°F, stepping down to 15 at -20°F. Either way, the rest of the wiring stays the same.
Can I use the wiring diagram that comes with the humidistat?
No. Use the HE360 humidifier drawing instead. The humidistat's own instructions are written for general applications, and they don't show how the HE360 red and yellow wires, the bundle 2 to bundle 3 white splice and the air switch fit together. Following the generic drawing is a common cause of a dead humidistat or a valve that never opens.
What power supply does the HE360 need?
The HE360 needs a standard 120 V AC, 60 Hz receptacle. It draws 0.7 A and connects with a plug-in cord, so you don't need a hardwired circuit. The outlet must be within reach of the cord from the humidifier's location on the supply plenum. If there isn't one, have a licensed electrician install it under local code. Unplug the cord whenever you wire or service the humidifier.
Can I mount the humidistat on a wall instead of the duct?
Yes. You can mount the humidistat on the return plenum or on a wall in the living space. Duct mounting makes the shortest, simplest wire runs. If you choose the return duct, place the humidistat at least 8 in. upstream of the humidifier so it senses room air, not humidified air. For a wall mount, run the wires through the back of the base, and plan for longer bundles.
Can I wire the HE360 to my furnace control board instead of using an air switch?
That setup isn't covered here. The HE360 wiring shown uses its own plug-in power and an air switch to sense the blower. It doesn't connect to any furnace terminal. If you want to wire it to a furnace humidifier output, check the furnace's documentation for that output's voltage and rating first. Have an HVAC professional confirm it is compatible with the 24 V solenoid valve before you change the wiring.
