Humidifier Valve 4040 Solenoid Valve Brass Air Valve.
All Aprilaire humidifiers (except models 110, 112, 350, 360) use the # 4040 24 Volts AC Solenoid Valve.  Most newer Honeywell, Skuttle, Herrmidifier, Autoflo, and Lobb humidifiers also use a 24 volt solenoids.
Most humidifier solenoid valves are operated on 24 Volt AC power, which is the predominant low voltage wiring standard for conventional HVAC controls.  24 Volt wiring is thin, 18 gauge wire - much smaller than 110 or 240 Volt line voltage wiring.

• [Parts Number]:4040 Yellow Solenoid Valve Replacement for Humidifier 24V
• [Function]: Ensures proper humidity levels by controlling correct water flow into the humidifier
• [Humidifier Model]:400, 400M, 500, 500M, 600, 600M, 558, 550A, 550, 568, 560A, 560, 700, 700M, 768, 760A, 760
• [Matching products]: Humidifier, Aprilaire 400, Aprilaire 500, Aprilaire 600, Aprilaire 700, Aprilaire 400M, Aprilaire 500M, Aprilaire 600M, Aprilaire 700M, Aprilaire Bypass Humidifiers except 330, 350, 360, 445, 110, 112

• [Fixes Following Symptoms]:

  • old valve
  • not shutting off
  • unresponsive
  • allowing water to run continuously

• [Specifications]:

  Model No.: A2012
  Pressure: 125 PSI
  Volt: 24 VAC
  Frequency: 50/60 HzOrifice：3/64
  Material: brass and copper wire

• [What others said about it on Amazon]:

• 1. It is much quieter.
• 2. Easy install replacing a Solenoid Valve that didn’t fully shut. Works as designed.
• 3. My original started leaking water out of the solenoid bolt. I ordered this replacement and within minutes, had them swapped out.
• 4. used for #700 April air humidifier easy to install.
• 5. Very easy to install and made our humidifier work again. Hard to believe what a difference such a little part can make for your home for such a low price.
• 6. This was a direct fit for my humidifier. Worked well.
• 7. Easy swap out on my Aprilaire 600 Series.
• 8. I Had a 20-year-old AprilAire humidifier, with a sticking solenoid. ordered this unit, and had it swapped out in less than 10 minutes.
• 9. Easy 10-minute install on Aprilaire 500.
• 10. This was a replacement valve for my carrier humidifier. The original valve I found was close to 100 dollars this is the same valve at a fraction of the price. Simple to remove the old valve and replace it with a new one.
• 11. Easy to install and saves an expensive service call. Be sure to order the correct orifice size for your humidifier if you buy this product also be sure to use the new compression fittings that come with the product or it will leak.
• 12. This valve was exactly a fit for replacing the stuck open solenoid valve on my April Air Humidifier. Was easy to install. Works great!
• ….

•   [FAQ]:

Q: Will this work with a “general“ brand on the furnace humidifier? The numbers on my current label are as follows: 24/60, 8.5 watts, and 3/32 orifice.

A: The specs do align with the 4040 valves. You’ll have to verify that the mechanical appearance would fit your specific installed unit. One common failure is that the valve orifice can clog if your water source has high amounts of calcium deposits or sand.

Q: My solenoid is RP corporation and has b2015-s51 but the orifice is 3/32. this one states the orifice as 3/64 will this size difference be a problem?

A: Quite a bit smaller and no expert but would reduce flow.

Q: Does this valve include an in-line strainer? (brass) so I do not need to purchase a plastic one?

A: Yes it does.