Can’t find your part?   Contact us:
+1-309-603-4777
Sears Parts Direct
Tips to find your model number
Orders

  • Keep track of the models you own in your profile

    Sign in or Register to view or add models

Schedule a repair
Aprilaire
Humidifier

Model # 550 Official Aprilaire humidifier

Here are the diagrams and repair parts for Official Aprilaire 550 humidifier, as well as links to manuals and error code tables, if available.

There are a couple of ways to find the part or diagram you need:

  • Click a diagram to see the parts shown on that diagram.
  • In the search box below, enter all or part of the part number or the part’s name.

Not all parts are shown on the diagrams—those parts are labeled NI, for “not illustrated”.

We encourage you to save the model to your profile, so it’s easy to access parts and manuals for your appliance whenever you log in.

For DIY troubleshooting advice and repair guides, visit our repair help section.

Owner’s manual

Model diagram and schematic

SEARCH WITHIN THIS MODEL

?

This is the number corresponding to the part on the diagram / schematic

Search
ALL PARTS
Showing 10 of 24 parts  |
Transformer 4010
#14

Model 550 diagram

Transformer

Part #4010

The manufacturer no longer makes this part, and there's no substitute part

Wick Pad 10
#1

Model 550 diagram

Wick pad

Part #10

The manufacturer no longer makes this part, and there's no substitute part

Base 4219
#4

Model 550 diagram

Base

Part #4219

The manufacturer no longer makes this part, and there's no substitute part

Feed Tube With Compression Sleeve 4226
#19

Model 550 diagram

Feed tube with compression sleeve

Part #4226

The manufacturer no longer makes this part, and there's no substitute part

Nozzle 4184
#16

Model 550 diagram

Nozzle

Part #4184

The manufacturer no longer makes this part, and there's no substitute part

Compression Fitting And Strainer (6) 4003
#11

Model 550 diagram

Compression fitting and strainer (6)

Part #4003

The manufacturer no longer makes this part, and there's no substitute part

Temperature Compensating Humidistat 55

#NI

All parts diagram

Temperature compensating humidistat

Part #55

The manufacturer no longer makes this part, and there's no substitute part

Insert 4217
#2

Model 550 diagram

Insert

Part #4217

The manufacturer no longer makes this part, and there's no substitute part

Cover Latch Spring 4225
#17

Model 550 diagram

Cover latch spring

Part #4225

The manufacturer no longer makes this part, and there's no substitute part

Valve 4040
#9

Model 550 diagram

Valve

Part #4040

The manufacturer no longer makes this part, and there's no substitute part

Parts & More