Appliance · AprilAire

AprilAire 400 Whole-House Humidifier (400A, 400M)

verified 2026-10-13 Specs from AprilAire shop - 45 Replacement Water Panel. Also known as: aprilaire 400, aprilaire 400a, aprilaire 400m.

Specs

typewhole-house humidifier

Takes

  • humidifier pad AprilAire #45 water panel
    Water panel for the AprilAire 400 series (400, 400A, 400M, 400KZ, 400MKZ) humidifiers.

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Good to know
  • Same nominal 13 x 10 x 2 in as the #35, but AprilAire lists #45 only for the 400 series and #35 for the 600/700 series.

What fits the AprilAire 400 Whole-House Humidifier (400A, 400M)?

1 parts and accessories in the graph work with this model. OEM parts first.

humidifier pad

Informational only. Confirm with the manufacturer before buying or installing. Spotted a mistake? Report it.