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

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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

Base 4219
#4

Model 550 diagram

Base

Part #4219

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

Current Sensing Relay 50

#NI

All parts diagram

Current sensing relay

Part #50

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

Drain 4223
#8

Model 550 diagram

Drain

Part #4223

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

Adptr-vlv 4229

#NI

All parts diagram

Adptr-vlv

Part #4229

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

Compression Fitting (6) 4076
#13

Model 550 diagram

Compression fitting (6)

Part #4076

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

Tube-drain 4047

#NI

All parts diagram

Tube-drain

Part #4047

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

Humidistat 4016
#15

Model 550 diagram

Humidistat

Part #4016

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

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