Aprilaire #4040 Solenoid
Original Aprilaire #4040 replacement solenoid valve. Note: Valve styles may vary.
- 24 VAC
- 2.3 Watts
Replacement solenoid value for Aprilaire Humidifier models 220, 224, 400, 440, 500, 550, 558, 560, 568, 600, 700, 760, 768. The #4040 soleniod valve includes a new inline strainer (pre-inserted in inlet side of valve), and a compression nut & washer for the inlet side only.
Solenoid Valve Replacement Instructions
- For power units unplug electrical cord. For bypass units turn off power to furnace. Also turn the humidistat off.
- Shut off water supply at the saddle valve
- Disconnect inlet and outlet water compression nuts. Double wrench. Note, some water may drip on floor. Remove the orifice (which controls the water flow) from the plastic or copper tube and make sure there is no obstruction. If blocked clean or replace.
- Remove the wire nuts from the water solenoid valve wire connections. Set aside.
- Remove screws that secure valve to unit.
- Attach new valve with screws. Do not over-torque screws into plastic housing.
- Reconnect wires with wire nuts.
- For units with plastic feed tubes inspect for brittleness, hairline cracks, nicks or abrasions, etc. Replace if necessary.
- Reconnect the water lines, double wrenching the compression nuts.
- Turn water back on and check system for leaks. Tighten compression nuts as necessary.
- Restore electrical service and activate furnace by turning up the thermostat.
- Turn up humidistat to verify operation of humidifier. Recheck for leaks. Turn down humidistat to make sure valve shuts off. Reset humidistat and thermostat to original levels.
AprilaireHumidifierParts.com Price:
$54.95
Customers most agreed on the following attributes:
Comments about Aprilaire #4040 Solenoid:
It was easy to install and works great. My last solenoid only lasted two years so I'm hoping this one is more durable.
Comments about Aprilaire #4040 Solenoid:
Very easy to install!
Comments about Aprilaire #4040 Solenoid:
The product is just what I needed. Looks like they might have updated design from my original which was sticking closed and not letting water through. It only took a few minutes to replace the old one with this new one and everything is working great now.
Comments about Aprilaire #4040 Solenoid:
I owned an Aprilaire humidifier for over 15 years. The solenoid that was installed over 15 years ago finally stopped functioning (great longevity). I ordered a replacement solenoid, and it was easy to install, works perfect and I expect I'll get another 15 years + out of this one.
Comments about Aprilaire #4040 Solenoid:
To replace or not to replace a faulty solenoid, that is the question. Whether my mental exercise in eliminating possibilities as to the working of the old solenoid is effective becomes moot if I just buy a new one and hope for the best. Alas, without equipment it is impossible to electrically verify the old solenoid; if it has failed, I must assume that 8 years is the taxable limit on such devices. So I'll buy the dang thing, hook it up and hope to avoid writing another review. - DONE. The new solenoid installed exactly as the old and works great. It would have been nice to have wire nuts included in the package however.
Comments about Aprilaire #4040 Solenoid:
Good part but didn't include the filter strainer that was supposed to be included as per the the instructions.
Comments about Aprilaire #4040 Solenoid:
Arrived promptly, just as advertised, and easy to install. All at a fraction of the estimate from the local service/repair company.
Comments about Aprilaire #4040 Solenoid:
This is a great replacement, note that is came with a in-line strainer.
Comments about Aprilaire #4040 Solenoid:
Received timely. Saved $260 by installing myself.Easy to install. A/C company wanted $330 to install a part that cost [$].
Comments about Aprilaire #4040 Solenoid:
PRODUCT WAS VERY EASY TO INSTALL AND IT WORKS JUST FINE. SAVED ATLEAST 150.00 IN PLUMBER FEES.





