Thetford 42141

Also check Amazon

• Check price on Amazon

  We earn a small commission if you buy through this link. It costs you nothing extra.

Compatible models, and the document that says so

• Aqua-Magic Style II

  Verified against Thetford Parts List, Aqua-Magic Style II (Rev D).

• Aqua-Magic Residence

  Verified against Thetford Service Kit instructions, Waste Ball Seal Kit (Form No. 42142 Rev. A).

Not compatible with

Aqua-Magic Style Plus. Thetford’s Style Plus parts list assigns 34120 as that model’s waste ball seal, not 42141. Some retailer listings claim one seal covers both. Thetford’s own parts lists do not.

Commonly confused with this

• 34120. 34120 is the waste ball seal for the Aqua-Magic Style Plus. 42141 is the one for the Style II and Residence. They are listed on separate Thetford parts lists and are not interchangeable.

How to tell which one you have

Thetford publishes a serial number location sheet showing where the sticker sits on each model. Find the sticker and read the model name off it, because Style II and Style Plus look similar but take different seals.

Is this part still current?

Yes. 42141 is listed in Thetford Parts List, Aqua-Magic Style II, Rev D (11/4/2025), which is the current parts documentation we hold for this model.

Also worth having before you start

• Disposable nitrile gloves

  General guidance for any waste-contact job, not specific to one manufacturer: wear protective gloves and eye protection when you touch anything that has been in contact with human waste, and disinfect your tools and work surface afterwards. If you do not already have a box in the camper, get one 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 Style II or a Residence, not a Style Plus.
• If it is a Style Plus, you need 34120 instead.
• Ignore listing titles that claim one seal fits both. Thetford lists them separately.

Before you start the job

Thetford’s own instructions say to wear protective gloves and eyewear when touching material that has been in contact with human waste, and to disinfect tools and the work surface afterwards.

Everything documented for this appliance

• Aqua-Magic Residence — 10 part numbers
• Aqua-Magic Style II — 6 part numbers

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.

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 ourselves, so everything here comes from the documentation rather than from a workshop.

• Thetford Parts List, Aqua-Magic Style II (Rev D), dated 11/4/2025. Published by Thetford Corporation.
• Thetford Service Kit instructions, Waste Ball Seal Kit (Form No. 42142 Rev. A), dated 27/07/2012. Published by Thetford Corporation.
• Thetford Parts List, Aqua-Magic Style Plus (Rev E), dated 11/4/2025. Published by Thetford Corporation.

Last checked 2026-08-24.

Related parts

• Also fits the Aqua-Magic Residence

  Thetford 34122: Vacuum Breaker

• Also fits the Aqua-Magic Residence

  Thetford 34124: Nozzle - White

• Also fits the Aqua-Magic Style II

  Thetford 42049: Water Valve

• Also fits the Aqua-Magic Residence

  Thetford 42067: Pedal - White (High)