Plan the wetroom, match the tray and waste outlet, and fit the C223-CS toilet, service door and Cleo tip-up sink.
Updated: 7 October 2026
In this chapter
Stainless steel tray or plastic toilet tray? · Compare bathroom kit sizes · Guide to Campervan Toilets: · Installation of the C223-CS Shower Tray: · Installation of the Cassette Toilet Thetford C223-CS · Thetford Service Door Model 3 · The Cleo Tip Up Sink
Stainless steel tray or plastic toilet tray?
Choose the tray by its exact dimensions, toilet compatibility, support requirements and waste position. For stainless steel trays, follow the current tray’s fitting instructions and product drawing. The plastic C223 trimming methods below do not apply to stainless steel.
Choose a compatible 19mm or 28mm waste outlet and pipe system. Outlet connection size is different from the hole cut-out diameter. Dry-fit the actual fitting and check the underfloor route before making holes.
Bathroom Installation
Guide to Campervan Toilets:
C223-CS: electric-flush swivel cassette toilet supplied from the vehicle’s fresh-water system. Check current dimensions and the exact tray combination before planning the room.
POSSIBLE C223 CS TOILET WETROOM LAYOUTS:
LEFT OR RIGHT HAND SHOWER TRAY, DEPENDING ON ORIENTATION (4 CM DEPTH)- View Layout
SQUARE SHOWER TRAY (10 CM DEPTH) – View Layout
C224: check the exact model’s flush-water arrangement and its installation manual. Do not rely on a model-family name alone when selecting a water supply.
Choose the tray handedness and dimensions for the actual layout; the manual’s “5mm depth” entry conflicts with its other tray dimensions and is not a verified specification.
C403: check the model’s onboard-water connection, handedness and cassette access against the current product details.
C402: check the model’s flush-tank arrangement, handedness and cassette access against the current product details.
Porta Potti 165 – Portable toilet with a manual flush system. Has its own 15 litre flush water tank so does not require connection to the onboard tank.
Compare bathroom kit sizes
Compare the toilet and tray combinations below when planning your campervan bathroom. Dimensions are taken from our conversion guide and describe the listed combination, not the full enclosure or cassette-removal clearance.
| Toilet + tray | Overall dimensions | Planning notes | Products |
|---|---|---|---|
| C223-CS electric toilet + C223 LH or RH tray | 1160 × 695mm | Guide gives a trimmed size of 940 × 675mm. | View compatible tray |
| C224 manual toilet + C223 LH or RH tray | 1160 × 695mm | Guide gives a trimmed size of 940 × 675mm. | View kit |
| C223-CS electric toilet + C400 tray + surround | 1105 × 575mm (±5mm) | Overall combination size quoted in the guide; confirm against the selected tray and surround. | View kit |
| C402 toilet + C400 tray | 940 × 675mm | Guide combination size for the plastic tray; check the selected material and option. | View kit |
| C403 toilet + C400 tray | 940 × 675mm | Guide combination size for the plastic tray; check the selected material and option. | View kit |
LH = left hand; RH = right hand. Check the selected product’s drawing, handedness and permitted trimming area before ordering or cutting. Allow space for wall construction, waste pipework and cassette access. Plastic-tray trimming dimensions do not apply to stainless steel trays.
Installation of the C223-CS Bathroom Overview
This section covers the C223-CS and compatible plastic C223 tray. Other toilet families, stainless steel trays and different trays need their own dimensions, supports and instructions.
Check the current C223-CS technical drawing, water connections and electrical installation details in Thetford’s C220 support and installation manuals.
The C223 Shower Tray fits neatly around the toilet to provide a seamless finish.
When used with the Service Door Model 3, the waste cassette can be accessed from the outside, without needing to carry it through the van. The Door is made of plastic material, it’s water resistant, UV-resistant and with the push-lock you can easily open and close the door.
The Cleo Tip Up sink and Cabinet fits neatly on the wall next to the toilet, complimenting the C223-CS bathroom kit.
Before you begin
It is assumed that you would already have an onboard tank, such as the Water Tank and Waste Tank installed prior to installation, or know their positions. See Waste and Water Tanks.
Getting Started
Important!
Before you start, it is important to check the position of the Toilet and Tray to ensure that the Waste Drain and Service Door Model 3 are not blocked. Check under the van and coordinate the pipework from the Waste Outlets to the Underslung Waste Tank. You want the easiest route giving the best flow, avoiding cutting out over the chassis, or cross members, wires, fuel lines etc.
Should you require additional clearance to run pipework beneath the shower tray, or so there is clearance for the waste cassette to be removed from the toilet through the external door, you can set up a raised platform by using timber battens and 12mm thick plywood – see floor.
If you are using the Service Door Model 3 to access the Waste Cassette, check to make sure that the height of the C223 Shower Tray is coordinated with the Service Door Model 3 levels as it requires a cut-out in the side of the van. You don’t want to cut out the side of the van if it clashes with plastic trims etc.
Installation of the C223-CS Shower Tray:
Key Steps:
For a compatible plastic LH/RH C223 tray, check the current product drawing for the overall dimensions and permitted trimming area. The manual gives 1160 × 695mm and a possible trimmed size of 940 × 675mm, but only trim where the exact tray manufacturer allows. These are not instructions for a stainless steel tray.
Select the drain position after checking the chassis, exhaust, crossmembers and services beneath it. Use the hole diameter specified by the exact waste fitting: 19mm or 28mm describes the pipe connection and does not by itself determine the cut-out size. Plan sufficient fall and a clear route to the waste tank.
Installation:
The shower tray requires supporting edges around the entire frame. There are 2 options for this 1) build a frame 2) use the enclosure walls as a barrier. Remember, a raised floor may be required to allow room for waste pipework and to align the back of the toilet with the access door.
Option 1) Build a frame for the shower tray. This will give support for the shower tray and also give a good straight edge for which the enclosure walls can be built up from. You can also build the same size frame and fix to the ceiling, forming an edge for the bathroom walls to fix against. Once constructed, glue the frame to the shower tray
Option 2) Alternatively, use the enclosure walls as an edge. Install a plywood base beneath the tray (cut to the same size as the tray) to ensure stability. If progressing with this option, the waste outlet hole will also need to be drilled through the plywood base.
There is a slight recess beneath the shower tray (to make anti-slip where you will stand when showering). This needs a supporting structure to ensure it does not crack beneath your weight. The shower tray support for the under tray recess can be done a number of different ways – here are a couple of the most popular:
Option 1) Build a platform like the below image. Creating a platform will support the raised piece and protect it from cracking and breaking.
Support the standing area with a frame/base shaped for the exact tray, with suitable moisture-resistant protection. A coating does not turn ordinary plywood into waterproof or marine-grade plywood.
Once the support is complete, fit the tray using the manufacturer’s fixing and watertight-joint method. Test drainage and check joints before closing the enclosure.
Installation of the Cassette Toilet Thetford C223-CS
1. Fix the toilet at the points and with the fasteners specified in its installation manual. Check alignment with the cassette access before final fixing.
2. Connect the flush-water supply using the fittings specified for the actual toilet and water system. The manual’s reducer sizes are examples, not universal requirements.
3. Connect the electrical supply and any pump-control circuit strictly to the wiring diagram for the exact C223-CS version. Pressure-pump and separate-pump arrangements differ; do not connect by wire colour alone.
Use connectors, cable sizing and circuit protection specified by the current installation manual.
If the flush does not work, isolate power and work through the manufacturer’s troubleshooting instructions:
Ensure there are no kinks in the water feed.
Check the supply, fuse, connectors and the correct wiring diagram rather than treating a twisted positive wire as a specific diagnosis.
Thetford Service Door Model 3
Although the standard way to remove the waste cassette from the toilet is via a service hatch cut into the exterior of the van, some self-builders will opt to install an access point inside the van. If removing the cassette through the interior, ensure that there is enough clearance for the waste tank:
Use the exact toilet/cassette drawing to check removal clearance. A generic cassette size quoted for another toilet family is not a cutting template.
Installing the Service Door
NOTE: We are frequently asked questions about the cassette not being able to pass through the external door. It's important to note that the external door is intended to swing open, meaning the cassette isn't meant to go straight through the door's center. For a clearer understanding, please refer to the image to the right.
Follow the current Model 3 manual and toilet template for door position and hinge direction; check that the cassette can be removed through the fully open door.
First off, check the minimum available space for the door. For the door to be above the black plastic sidebar, you may have to raise the shower tray on which the toilet and the waste tank will be standing.
Use the supplied templates for the exact door/toilet version. Confirm their scale, position and clearance before cutting, and protect the surrounding paintwork.
The (B) cutout wall panel will be the door panel, so you should only cut in the indicated places, especially so you can keep any decorative stripes on the final piece for the door panel.
Once cut-out, check if the plastic external door frame fits and then remove the tape.
The other template (A) is for the door panel infill. Now you really have to focus on the right position so that the colour or any decorative straps on the panel will match and align the ones on the vehicle. To prevent any scratches, use some tape and draw the outlines.
The Thetford service-door manual specifies a wall thickness of 23–39mm. A thin metal van wall may need a properly designed reinforcing frame and door-panel infill to suit the specified build-up.
Glue the wooden frame to the cutout hole of the vehicle wall with adhesive and fasten it with clamps until it is dry. The wooden frame has to be fixed and the glue dried completely before installing the plastic frame of the service door to prevent the pull of the screws from pushing in the metal. You can prevent this from happening by installing the wooden frame first and then the plastic frame.
Prepare and fit the door-panel infill using the waterproofing and fixing method specified in the service-door manual.
Fit the outer and inner frames using the manufacturer’s joint and fastening instructions. Check the door operation and water tightness after curing.
The Cleo Tip Up Sink
The Cleo Tip Up Sink is our most popular sink option for campervan bathrooms, particularly in the C223 bathroom campervan set-up. The Contessa Tip Up Sink is a popular option where the C402 or C403 toilet system is installed – both the Cleo Sink and Contessa Sink are fitted in a similar way.
The tipped-up basin drains into the catchment behind it, then through its outlet. Check the current Cleo outlet size and connection kit before routing the waste; the manual describes a 19mm connection.
Only certain taps will fit the Cleo and Contessa Sinks due to the internal space in the basin once closed. No pre-drilled holes exist, so a hole for the tap will be required. The Comet Roma is often preferred when the sink is used with a tap. Where a Shower-Tap is preferred, the Parma Shorty is our most popular option. The entire basin can easily be lifted out where additional space is required in the bathroom when using it as a shower.
The sink is installed via 6 surface mounting screw holes. Some prefer to fix a pattress behind the wall so the cleo sink is recessed and allows more space in the bathroom (picture left).
Check the whole bathroom before finishing
- Cassette clears the fully open service door and can be removed without dismantling the room.
- Tray is supported under the standing area and around the edges as its manufacturer requires.
- Drainage has a clear route, suitable fall and access for cleaning.
- Water and waste connections have been tested before closing the enclosure.
- Toilet electrics follow the exact model’s wiring diagram and circuit protection requirements.
Mock up the whole bathroom
Test the bathroom with the actual toilet, tray and basin dimensions, rather than the tray footprint alone. Allow room for sitting, standing, operating the shower and opening doors. Check where the cassette is removed and whether surrounding furniture blocks that route.
Plan plumbing, drainage and ventilation before constructing the enclosure. Keep the waste outlet and service connections accessible. Bathroom materials need to suit regular moisture exposure; the tray alone does not make the surrounding walls and floor watertight.
Separate the dimensions used for ordering from the space needed to use and service the bathroom. The comparison above is a starting point: confirm the current product drawings and installation manual before cutting or buying components.
Products for this job
- LH / RH Shower Tray Options (to Suit Thetford C223 C224 Cassette Toilet)
- Cleo Tip-Up Sink Wash Basin
- Cleo Cabinet
- Comet Roma 12V Micro Switch Hot Cold Mixer Tap
Universal stainless steel shower tray
Campervan water and waste tanks · Water-tank mounting straps · 19mm waste outlets · 28mm waste outlets
Keep building
Browse the complete converter guide · Original illustrated PDF