The lower waste cassette on a C220-series toilet contains several assemblies that can look alike: the blade, sealing ring, pour-out spout, vents and carry mechanism. This guide helps identify the component on the removable tank, rather than confusing it with a C223-CS bowl, control panel or complete toilet.
Locate the tank component you are comparing
Where it seals
Compare the blade, moving cover and sealing ring
Where it empties and vents
Find the spout, button, cap, foam and vent seal
Where it locks and carries
Find the two wheels, axle, clip, handle and float
The callout numbers here refer to the removable C220 waste-holding tank. The separate C223-CS toilet-body illustration starts its numbering over, so a matching number there does not identify the same component.
C220 tank: identify all 23 original callouts
Match the callout on the factory illustration with the component and assembly reference. Repeated numbers, such as 200973 for a spout and O-ring, are grouped references. Do not assume each component is available by itself.
| No. | Tank part | Thetford no. | What the number covers |
|---|---|---|---|
| 1 | Wheels (pair) | 200640 | Wheel-and-axle service grouping, refs. 1–2 |
| 2 | Axle | 200640 | Same 200640 grouped reference as the wheels |
| 3 | Tank-lock clip | 23849 | Clip securing the cassette in its installation |
| 4 | Transport-handle grip | 200966 / 200965 | Grip listed separately; also included in handle grouping |
| 5 | Transport handle | 200965 | Grouped with grip at ref. 4 |
| 6 | Transport-handle bracket | 200968 | Bracket associated with transport assembly |
| 7 | Tank blade | 50731 | Moving blade at waste inlet |
| 8 | Blade opener | 200970 | Mechanism for operating tank blade |
| 9 | Float arm | 200971 | Waste-level indicator linkage |
| 10 | Carry handle | 200972 | Separate carry handle on top of tank |
| 11 | Pour-out spout O-ring | 200973 | Grouped with spout at ref. 12 |
| 12 | Pour-out spout | 200973 | Spout and O-ring grouped service number |
| 13 | Measuring cup | 200967 | Pour-out cap / measuring-cup component |
| 14 | Automatic vent | 23722 | Automatic vent service grouping, refs. 14–16 |
| 15 | Vent foam | 23722 / 23788 | Associated with automatic/outside-vent groupings |
| 16 | Vent seal | 23722 / 23788 | Shown with both vent service groupings |
| 17 | Outside vent | 23788 | Outside-vent service grouping, refs. 15–17 |
| 18 | Sliding cover | 50718 | Removable cover for tank's blade area |
| 19 | Retainer seal | — | No individual order number in Thetford's table |
| 20 | Waste-tank lip seal | 23721 / distributor 50192 | Lip seal around the tank's inlet opening |
| 21 | Vent button | 07524 | Vent-button service grouping, refs. 21–23 |
| 22 | Vent spring | 07524 | Grouped with vent button and seal |
| 23 | Vent seal | 07524 | Grouped with vent button and spring |
Check the cassette version before replacing a part
Thetford's C220 tank table distinguishes a standard complete cassette numbered 200977 from the 200978 outside-vent version. A later C223-CS model sheet calls the complete tank 20097706. Compare the tank's data label and vent arrangement rather than ordering solely by the toilet's model name.
The complete C223-CS toilet carries MPN 200866SP. That is not a replacement cassette part number. Confirm whether your existing tank has the outside vent, and match the original identification markings.
Model-identification photograph from UsedRVParts
The available catalog image shows the complete C223-CS toilet, helping you distinguish the fixed toilet from the removable C220 holding tank. Consult the product listing for its stated condition and availability. Where applicable, UsedRVParts viewing and pickup in Kelowna are by appointment.
Check the original tank drawing before ordering
Open Thetford's original numbered tank exploded view and the 23-callout manufacturer's parts table. The drawing identifies individual component positions, and the following page shows the part-number groupings.
The separate Thetford C223-CS parts sheet identifies the newer complete tank reference 20097706. Use the tank label and the correct manufacturer's service drawing to confirm the version.