Question about Humidifiers

Open Question

Wiring in a 120 volt relay

I would like to know the wiring for a Idec RH2B-U Relay
What I have is an inline exhaust fan for a bathroom & the electrician ran 18 gauge wire to the switchs I think i am on the right track by using this relay.
I,ve done a lot of work with Bosch automitive relays but never used a 120 volt relay so I have no idea on how to wire it The fan has never been hooked up

It is 120 in & 120 Out 10 Amp

Posted by on

1 Suggested Answer

  • 4369 Answers

SOURCE: My Aprilaire 760 humidifier will not turn on. I

you should have an upstream and a down stream sensor and maybe a remote sensor too. They could be the issue. Google aprilaire 760 humidifier installation instructions at aprilaire's site and see where and how many you have. It cold be the control module too. Try too. good luck

Posted on Dec 01, 2010

Add Your Answer

0 characters

Uploading: 0%


Complete. Click "Add" to insert your video. Add


1 Points

Related Questions:

1 Answer

Have a aprilair 550 for some time. Installed a new Lennox G61MP furnace and the technitions failed to reconnect the wiring that powers the humidifier. Need wiring schematic. Does humidifier transformer get...

Hello, yes the transformer will get a 120 volts from the Furnaces control board, there should be a terminal labeled HUM on the control board. You need to bring 2 wires one from HUM and one from a nuetral tap on the board to the line side of the transformer, this way every time the blower motor on the Furnace turns on the humidifier will aswell.

Aug 23, 2011 | Aprilaire 550 Humidifier

1 Answer

The water not reaching the humidirier and the fan runs couinnuously

Hello, water not reaching the humidifier can be caused sediment buildup in the strainer of the solenoid valve, a faulty solenoid valve, sediment at the saddle valve, or no power to the solenoid valve. The fan will run continously if the relay that engages the fan is stuck as it is gettimg a constant 120 volts.

Jul 06, 2011 | General Filters 1042-LH Humidifier

1 Answer

I have a Aprilaire 760. I have already tested the brown wires. The fan is still not running. I have power to the unit.

Hello, are you getting 24 volts to the solenoid vlave? If you are and the solenoid does not open it must be replaced, the 24 volts opens the solenoid and also energizes a small relay to turn on the fan. If you are not getting 24 volts to the solenoid valve then start at the transformer and work you way toward the solenoid and see where the voltage stops.

Feb 26, 2011 | Aprilaire 700 Humidifier

1 Answer

I just installed a Honeywell HE 360 Humidifier I purchased at Home depot. I replaced a Aprilaire model 110 . I have a 120v power duplex that is hot with the furnace blower motor, on so I assumed the sail...

Hello, in order to turn your humidifier on with the furnace the 120 volts coming from your humidifer you must hook it up to a step down transformer, then the transformer will provide 24 volts to you humidistat and solenoid valve. So you need a wire from the HUM on your control board to transformer primary side and a wire from neutral on the board to primary side of transformer. Then you need low voltage wire from secondary side of transformer to humidistat from humidistat to humidifier.

Feb 20, 2011 | Honeywell HE360A1027 Whole House...

1 Answer

When furnance turns on and the blower kicks in the fan from the humidifier does not turn on ?

The first to check is if you are getting 24 volts to the solenoid valve and if you are getting 120 volts to the humidifier via receptacle.

Dec 29, 2010 | Aprilaire 700 Humidifier

1 Answer

I have an aprilaire 550 that is not working. I found 2 wires coming from the humidity control, one goes to the solinoid, the other is hanging in mid-air. Where is this second wire supposed to be...

Hello, it depends on what type of setup you have with your humidifier. If you have a current sensing relay or sail switch than that wire connects there, howevere, if you have the humidifier that is powered by a furnace control board than that wire will connect to the transformer that the control board is providing with 120 volts with.

Dec 27, 2010 | Aprilaire 550 Humidifier

1 Answer

Keep running

You should have a #50 relay hooked up to the main blower assembley to turn the 24 volts on and off with the blower to the humidistat. Alot of humidifiers sold do not tell you about the #50 relay. They assume that you are a hvac pro and you aready know about.
Good luck
HVAC Teacher

Mar 02, 2009 | Aprilaire 600 Humidifier

1 Answer

Aprilaire 600

If the water is always on make shure the 24 volts is hooked up to 24 volts only when the blower is on. Some furnaces have a HUM terminal but make shure it is 24 volts some are 120 volts you must use the transfomer with the AP 600. You may may use a RP50 relay. The setting 5 or 6 is about the avg setting slowly turn down to see if it shuts off .Also make shure the damper is in the winter setting. Hope this helps

Jan 26, 2008 | Aprilaire 600 Humidifier

1 Answer

Aprilaire 700

white wire on fan motor ( neutral ) is placed under clamp on relay , one yellow wire on relay goes to one wire on the solenoid valve , other yellow wire goes to the humidistat

Dec 13, 2007 | Aprilaire 700 Humidifier

2 Answers

My aprilaire 600 humidifier stays on when the blower shuts off

Make shure the 24 volts is hooked up to power that is only powered up when the blower is running. Some furnaces have a HUM terrminal on control (make shure the HUM is 24 volts some are 120 volts then you must use the transformer supplied with the AP 600). You can use a RP # 50 relay that senses current only when the furnace motor is running on the heating speed. Hope this helps

Oct 30, 2007 | Aprilaire 600 Humidifier

Not finding what you are looking for?
Humidifiers Logo

Related Topics:

894 people viewed this question

Ask a Question

Usually answered in minutes!

Top Humidifiers Experts


Level 3 Expert

1033 Answers


Level 3 Expert

1772 Answers

Barrett Palumbo
Barrett Palumbo

Level 2 Expert

1772 Answers

Are you a Humidifier Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides