Thetford 16833
Vacuum Breaker
Thetford 16833 is the vacuum breaker for the Cassette C200S-CS and Cassette C223CS and Cassette C223S and Cassette C224CW and Cassette402C.403L. The anti-siphon device on the water supply that stops water being drawn back out of the toilet into the fresh water line. Thetford lists it for Cassette C200S-CS, Cassette C223CS, Cassette C223S, Cassette C224CW and Cassette402C.403L. It is item 1 and 2 and 3 and 5 depending on the list.
Which models this fits
Cassette C200S-CS
Verified against Thetford Parts List, Cassette C200S-CS (Rev. D).
Item 1 on this parts list.
Cassette C223CS
Verified against Thetford Parts List, Cassette C223CS (Rev. D).
Item 2 on this parts list.
Cassette C223S
Verified against Thetford Parts List, Cassette C223S (Rev. D).
Item 2 on this parts list.
Cassette C224CW
Verified against Thetford Parts List, Cassette C224CW (Rev. E).
Item 3 on this parts list.
Cassette402C.403L
Verified against Thetford Parts List, Cassette402C.403L (Rev. D).
Item 5 on this parts list.
What this does NOT fit
Aqua-Magic Residence. Thetford's Aqua-Magic Residence parts list assigns 34122 to this position, not 16833.
Aqua-Magic Style II. Thetford's Aqua-Magic Style II parts list assigns 34122 to this position, not 16833.
Aqua-Magic Style Lite. Thetford's Aqua-Magic Style Lite parts list assigns 34122 to this position, not 16833.
Aqua-Magic Style Plus. Thetford's Aqua-Magic Style Plus parts list assigns 34122 to this position, not 16833.
Commonly confused with this
34122 is the vacuum breaker listed for Aqua-Magic Residence, Aqua-Magic Style II, Aqua-Magic Style Lite and Aqua-Magic Style Plus. 16833 is listed for Cassette C200S-CS, Cassette C223CS, Cassette C223S, Cassette C224CW and Cassette402C.403L. They appear on separate Thetford parts lists.
How to tell which one you have
Find item 1 or 2 or 3 or 5 on your model’s parts diagram — that callout is this part. Check the model on the data plate reads Cassette C200S-CS, Cassette C223CS, Cassette C223S, Cassette C224CW or Cassette402C.403L.
Is this part still current?
Yes. Thetford still lists 16833 on its current parts list.
Also worth having before you start
- Thetford seal lube and conditioner
A new seal lasts longer if it is kept conditioned. Thetford makes this for its own toilets, so it is the maintenance product matched to the part you are fitting.
These are supplies, not replacement parts. We have not matched them to your model, because they do not need to fit anything.
Check this before you order
- Confirm your toilet is a Cassette C200S-CS, Cassette C223CS, Cassette C223S, Cassette C224CW or a Cassette402C.403L.
- If it is a Aqua-Magic Residence, Aqua-Magic Style II, Aqua-Magic Style Lite or a Aqua-Magic Style Plus, order 34122 instead.
- Ignore listing titles that claim one part covers several models unless the manufacturer's parts lists agree.
Current marketplace inventory
Listings from eBay
We verified the part above from manufacturer documents. The listings below are current eBay inventory, and eBay sellers set their own titles, prices and shipping.
Checking current eBay inventory…
Camper Replacement Parts is not the seller. Price, shipping, stock and item condition are set by the eBay seller and can change at any time. We may earn a commission if you buy through these links.
Where our information comes from
We work from the manufacturer’s own documents. We have not installed this part and we do not test parts in a shop.
- Thetford Parts List, Cassette C200S-CS (Rev. D). Published by Thetford.
- Thetford Parts List, Cassette C223CS (Rev. D). Published by Thetford.
- Thetford Parts List, Cassette C223S (Rev. D). Published by Thetford.
- Thetford Parts List, Cassette C224CW (Rev. E). Published by Thetford.
- Thetford Parts List, Cassette402C.403L (Rev. D). Published by Thetford.
- Thetford Parts List, Aqua-Magic Residence (Rev. D). Published by Thetford.
- Thetford Parts List, Aqua-Magic Style II. Published by Thetford.
- Thetford Parts List, Aqua-Magic Style Lite (Rev. D). Published by Thetford.
- Thetford Parts List, Aqua-Magic Style Plus. Published by Thetford.
Last checked 2026-08-29.