Quick answer: This is the genuine ResMed tub plate seal (O-ring, part 26954) for the H4i cleanable water chamber (26958) — the sealing ring that keeps the H4i humidifier's water chamber watertight around the heater/tub plate. Because the cleanable chamber comes apart for washing, its seal is a wear item: over time it can harden, flatten, or tear, causing leaks. This inexpensive replacement restores a proper seal so the chamber holds water and heats correctly. Water chamber, lid, humidifier, and machine not included.
What's included
- 1 × H4i tub plate seal / O-ring (part 26954)
H4i cleanable water chamber (26958), flip-top lid & seal (26953), humidifier, and machine not included.
About this part
The H4i cleanable water chamber (26958) is designed to be taken apart for thorough cleaning — and this tub plate seal is the ring that seals it back up watertight, around the base/heater-plate area, when reassembled. It's a small but essential part: if the seal is missing, cracked, hardened, or deformed, the chamber can leak water or lose humidification performance.
- Restores a watertight seal — for the reassembled cleanable chamber.
- A wear/consumable part — seals degrade with repeated cleaning, heat, and time; replace when you see leaks or the seal looks worn/flattened.
- Genuine fit — sized correctly for the H4i cleanable chamber (a generic o-ring may not seal or may degrade fast).
Compatibility: for the ResMed H4i cleanable water chamber (26958), used with the HumidAire H4i humidifier on ResMed S8-series machines.
Key features
- Genuine ResMed H4i tub plate seal / O-ring (26954).
- Seals the cleanable water chamber (26958) — keeps it watertight.
- Replaces a worn seal — fixes leaks from a degraded ring.
- Inexpensive wear part — cheap fix vs replacing the whole chamber.
- For the H4i humidifier on ResMed S8-series machines.
Specifications
| Specification | Detail |
| Product type | Tub plate seal / O-ring (humidifier chamber part) |
| For | ResMed H4i cleanable water chamber (26958) |
| Humidifier | ResMed HumidAire H4i |
| Compatible machines | ResMed S8 series |
| Function | Seals the reassembled cleanable chamber (watertight around the tub/heater plate) |
| Type | Wear/consumable part |
| Included | Seal / O-ring only |
| Not included | Water chamber (26958), lid & seal (26953), humidifier, machine |
| ResMed reference / SKU | 26954 |
| Brand | ResMed |
Frequently asked questions
What is this part? It's the sealing ring (tub plate seal / O-ring) that makes the H4i cleanable water chamber watertight when you reassemble it after cleaning.
Why would I need it? The seal is a wear item. If your cleanable chamber starts leaking, or the seal looks hardened, flattened, or torn, replacing it restores a proper seal — much cheaper than a new chamber.
Which chamber does it fit? The ResMed H4i cleanable water chamber (26958), used with the HumidAire H4i humidifier on ResMed S8-series machines.
Is the water chamber included? No — this is the seal only. The chamber (26958) and the flip-top lid & seal (26953) are separate.
Do I need a prescription? No — this replacement part does not require a prescription.
Can I get it delivered in Brooklyn or shipped nationwide? Yes — Task Supply Corp offers USPS shipping throughout the continental U.S., plus local pickup and delivery in Brooklyn and all five boroughs of New York City.
Use with a compatible ResMed H4i cleanable water chamber according to the H4i user guide. Replace if the seal is worn, hardened, or leaking.