Whole-house furnace humidifier replacement water panels, pads and maintenance parts: matching the pad to the humidifier model (AprilAire 10/12/35/45 water panels, Honeywell HC22/HC26 pads, Carrier/Bryant, Lennox and GeneralAire panels), generic vs OEM, multipacks, and the solenoid/scale-control/drain-line parts that go with them
Buy by the humidifier’s model number, not by the pad’s size
A whole-house evaporative humidifier works by passing water over an absorbent surface while warm air from the furnace plenum moves through it. That surface is the water panel (AprilAire’s term) or pad (Honeywell’s). Panels of similar width and height are not interchangeable. Frame thickness, the way the panel sits in the distribution tray, and the panel’s footprint inside the cabinet all differ between product lines.
The number printed on the old panel is the safest starting point, but it may be rubbed off or mineral-coated. The more reliable source is the data label on the humidifier cabinet. It sits on the side of the unit or inside the cover and shows a model such as 600, 700, HE360 or 1042. Match that to the panel listed for it by the manufacturer.
Two mistakes cause most wrong orders. One is buying by the panel’s apparent size from a photo. The other is assuming that the furnace brand decides the humidifier brand. Many furnaces carry a humidifier from a different maker, and some Carrier and Bryant systems use a humidifier that was installed years after the furnace.
Model-to-panel lookup table
The pairings below come from manufacturer and retailer compatibility lists. Always confirm against the label on your own unit before ordering, because manufacturers revise their lists and some models have letter suffixes.
| Humidifier model on the label | Replacement part |
|---|---|
| AprilAire 110, 220, 500, 550, 558 | AprilAire Water Panel 10 (about 10 in. high, 9.75 in. wide, 1.75 in. thick) |
| AprilAire 300, 350, 360, 560, 568, 600, 700, 760, 768 | AprilAire Water Panel 35 |
| AprilAire 400 | AprilAire Water Panel 45 |
| Honeywell HE100, HE150, HE220A (also listed for HE225 and HE240) | Honeywell HC22P1001 pad |
| Honeywell HE200, HE250, HE260A/B, HE265, HE280, HE360 | Honeywell HC26-series pad (HC26P1002 or HC26A1008) |
| GeneralAire 1040 and 1042 flow-through | Vapor pad 990-13 |
| Carrier, Bryant, Payne humidifiers using the 318518-762 panel | Panel 318518-762 |
The AprilAire Water Panel 12 is a separate size and is not shown above, so check AprilAire’s water panel guide for the models it serves. Lennox Healthy Climate humidifiers list their pad number in the owner’s manual, which is the place to look rather than guessing from a photo.
If your model is not on a list, do not buy on dimensions alone. Look up the manual by model number.
Panel 10, 35 and 45: what separates them
The common question is whether a 35 can stand in for a 10. They are built for different cabinets. A 10 is the smaller panel, roughly 10 inches high by 9.75 inches wide, and serves the 110, 220 and 500 series. The 35 serves the 300, 350, 360, 560, 600, 700 and 760 series. The 45 belongs to the 400.
The shapes matter because water has to reach the panel evenly. On a bypass unit like the 600, water flows from a distributor onto the top of the panel and warm air from the bypass duct moves through the media. On a fan-powered unit like the 700 or 760, a blower pushes air through the panel instead. A panel that sits loosely or leaves a gap lets air go around the media, so the unit delivers less moisture than its rated gallons per day.
If your old panel was a different number from what the model list says, someone may have substituted a panel earlier. Go by the manual, not the panel currently in the cabinet.
Honeywell, GeneralAire, Carrier/Bryant and Lennox pads
Honeywell splits its pads into two families. The HC22P1001 serves the older HE100, HE150 and HE220A class. The HC26 pads serve the HE200 to HE360 range. The HC26A1008 is listed for the HE260 and HE360 and is a paper pad. Because the two families look similar, check the HE number on the cabinet rather than relying on pad appearance.
GeneralAire’s 1042 is a flow-through humidifier rated at 17 gallons per day at a 120°F plenum temperature, and its vapor pad is part number 990-13. The manufacturer says to replace it one to two times per season.
Carrier, Bryant and Payne humidifiers commonly use panel 318518-762. Lennox Healthy Climate units have their own pads. For both, the model number in the owner’s manual or on the humidifier’s data label is the one source worth trusting. If the humidifier was added years after the furnace, the furnace brand tells you nothing about which panel fits.
OEM vs compatible panels and multipacks
OEM panels (AprilAire-, Honeywell- or GeneralAire-branded) are made to the manufacturer’s specification and are the safest fit. Compatible panels from third-party filter makers are sold with a cross-reference to the OEM number, for example a generic that fits the AprilAire 35. They are usually cheaper per panel and can be a sound choice, but quality varies by maker.
What to check on a compatible listing: the OEM number it claims to match, stated dimensions, and your humidifier model among the listed fits. Listings that leave out dimensions or give only a vague ‘fits most’ claim are a poor sign. Mismatched thickness is the most common failure, because a slightly thin panel leaves air gaps and a slightly thick one can bind in the cabinet.
Multipacks make sense when you replace every season or more often. Hard water shortens panel life and a two- or three-pack saves reordering. Buy a multipack only after you have confirmed the first panel fits your cabinet, and store spares in a dry place, since an unused panel that sits in a damp basement can pick up odors.
Parts that go with the panel: solenoid, scale control and drain line
The panel is the part that wears out first, but other parts decide whether a new one performs. The solenoid water valve opens when the humidistat calls for humidity. If it is stuck or its screen is clogged, water feeding the panel is reduced or stops, so a fresh panel stays dry. A valve that does not close fully can leave water running to the drain.
The water feed orifice and distribution tray carry water onto the panel. Mineral scale can narrow the orifice, and a partly blocked one streaks the water so only part of the panel gets wet. Some humidifiers accept a scale-control insert or maintenance kit, which is worth buying for hard-water homes if your model supports one.
The drain line carries unevaporated water, with its dissolved minerals, out to a floor drain or condensate pump. A kinked or clogged drain line makes water back up in the cabinet and can leak. Check the saddle valve or supply fitting that feeds the unit, too. These are common sources of low flow.
Replacement schedule and signs a panel is spent
Plan on replacing the panel at least once per heating season. Some compatible-panel sellers say every six months, and GeneralAire says one to two times per season for its vapor pad. Hard water, long run times and an oversized unit running constantly all shorten that. Replace at the start of the heating season rather than the end, so you do not store a scale-coated panel for months.
Signs the panel is finished: a hard, crusty surface with white or tan mineral deposits, a panel that no longer wets evenly across its face, a musty smell, or visibly lower indoor humidity with the humidistat set unchanged. Between swaps, shut off the water supply and set the humidistat to off at the end of the season, then close the damper on a bypass unit. A clean unit and a fresh panel at the start of the season give the humidity the unit was rated for.
Shop whole-house humidifier water panel multipack for Whole-house furnace humidifier replacement water panels, pads and maintenance parts: matching the pad to the humidifier model (AprilAire 10/12/35/45 water panels, Honeywell HC22/HC26 pads, Carrier/Bryant, Lennox and GeneralAire panels), generic vs OEM, multipacks, and the solenoid/scale-control/drain-line parts that go with them
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FAQ
Which AprilAire water panel do I need, 10 or 35?
It depends on the humidifier model, not preference. The Water Panel 10 serves the 110, 220, 500, 550 and 558 series. The Water Panel 35 serves the 300, 350, 360, 560, 568, 600, 700, 760 and 768 series. Check the model on the data label, then match it to AprilAire’s panel guide.
Can I use a Honeywell HC22 pad in an HE260 or HE360?
No. The HC22P1001 is listed for the HE100, HE150 and HE220A class, and the HC26 pads (HC26P1002, HC26A1008) are listed for the HE200 to HE360 class. Use the pad for your HE number.
Are compatible water panels as good as OEM?
Some fit and work well, but quality varies. Choose a listing that names the OEM number it replaces, states dimensions, and lists your humidifier model. If the panel is loose or thicker than the original, return it.