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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.

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Owner’s manual

Model diagram and schematic

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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

Valve Sadd 4001
#18

Model 550 diagram

Valve sadd

Part #4001

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

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

Humidistat Adapter Plate 4039

#NI

All parts diagram

Humidistat adapter plate

Part #4039

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

Orifice 4231
#12

Model 550 diagram

Orifice

Part #4231

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

Insert 4217
#2

Model 550 diagram

Insert

Part #4217

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

Panel 4221
#6

Model 550 diagram

Panel

Part #4221

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

Parts & More