Model reference

Aprilaire 1870

HVAC

2 documents16 error codes2 service modes

Available documentation

Service Manual

Aprilaire Dehumidifier Troubleshooting Manual23 pg
Covers this model

Installation Guide

Installation Instructions16 pg
Covers this model

MyPros+ Max

Diagnose your Aprilaire 1870.

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Test values, resistance specs, and wiring references
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Error codes (16)

CodeMeaning

1 FlashSystem lockout 2 FlashesPressure switch stuck closed 3 FlashesPressure switch stuck open 4 FlashesOpen limit control 5 FlashesMissing jumper wire Continuous FlashingFlame sensed with no call for heat Continuous LightInternal control failure E1Internal %RH/Temperature Sensor Failure E2High Refrigeration Pressure E3Model 76 Remote Control Communication Loss E4Insufficient Capacity E5High Temperature Thermistor Failure E6Low Temperature Thermistor Failure E7Float Switch Open E8Inlet Air Temperature Out of Range E9Outdoor Temperature Sensor Failure

Service modes (2)

Diagnostic Data Display["With the dehumidifier running, press and hold the MODE and UP buttons for 3 seconds then…
Installer Test Mode["Use the ON/OFF button on the User Interface Assembly to turn the mode to OFF.","Flip the ON/OFF…

Full entry steps, exit procedures, and test sequences are available in Max.

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