C4
Instruction Manual
FEATURES
![]() | 1. Valve blade opener knob, opens and closes valve blade. 2. Removable seat and cover. 3. Flush the knob, and adds water to the bowl. 4. Waste level indicator – indicates when Cassette is full. 5. Water fill funnel – swings out for ease of filling the fresh water tank. 6. Drain tube assembly. 7. Toilet fluid storage compartments. (Only the high models.) 8. Cassette retainer clip – holds hol-wing tank in the locked position. 9. Automatic holding tank vent. | 10. Valve blade opener. 11. Cassette valve blade. 12. The sliding cover guarantees optimal hygiene. Opens and closes automatically by sliding the holding tank in and out. 13. Upper carrying handles – makes carrying and emptying easy. 14. Air release valve – ensures smooth emptying without splashing. 15. Lower carrying handles. 16. Handgrip. 17. Rotating pour-out spout – makes emptying Cassette easy and convenient. 18. Cassette access door – locks from outside Caravan. |
INTRODUCTION
By buying a Thetford Cassette Porta Potti you can be sure you have bought a Thetford quality product. The Thetford Cassette Porta Potti design is functional and incorporates modem sculpture styling with home-like features making it aesthetically compatible with the Caravan bathroom decor. The unit is an integral part of the Caravan bathroom.
The Cassette Porta Potti is constructed of high-quality plastics for durability and has a high gloss finish that is easy to clean and maintain. The unit consists of two sections, a permanently installed toilet system, and a slide-out waste holding tank – CASSETTE.
The toilet section includes a seal and cover, valve blade opener knob, flush knob, waste level indicator, built-in fluid storage compartment, a drain tube, and a freshwater tank.
The unique Cassette section is located underneath the toilet and is removed for emptying from outside the caravan through an access door. A rotating pour-out spout, automatic holding tank vent, air release valve blade, sliding cover, carrying handles, and handgrips are incorporated into the Cassette.
The Thetford Cassette Porta Potti is a unique solution to a Caravans’ sanitary problem.
PREPARING FOR USE
- \Open the access door on the side of the Caravan and swing-out the freshwater fill funnel.
- Add the given amount of Aqua Rinse through the waterfall funnel, which results in a better flush and improves the hygiene of the toilet. Then fill the water tank with fresh water using a hose or jenycan until the water funnel level reaches the neck. The tank capacity is 15 liters.
- Replace cap. Swing water fills the funnel inward until it touches the side of the water tank.
NOTE:150 ml. of water will remain in the filled bottle when the fresh water tank is empty. - Remove the Cassette by pressing the retaining dip down.
- Remove Cassette by pulling it straight out. When Cassette hits stop, tilt downward slightly and remove (stop for safety when Cassette is full).
- Position tank vertical and swivel pour out spout upward.
- Remove cap. Remove toilet fluid from the storage compartment. Add a given amount of toilet fluid by pouring out the spout. Add water until the bottom of the Cassette is completely covered with liquid. Replace cap and tum pour out spout to its original stored position.
Note: The cap of the pour-out spout is packed together with the instructions for use. Hotter weather or a longer retention time may require the addition of more toilet fluid.
CAUTION: Never add toilet fluid through the valve blade or the toilet bowl. Pressure due to heat and altitude change can build up in the Cassette tank causing contents to splash upward upon opening in the valve blade is opened too fast. - Slide the Cassette, pour out the spout facing outside, into the caravan through the access door. Be aware that the sliding cover is placed correctly; the two arrows on top have to be pointing towards each other.
- Make sure that the Cassette is locked with the Cassette retainer clip.
OPERATION
flushing
- In order to prevent overpressure at high temperatures or differences in heights, open and close the valve blade once before using it. Then add water to the bowl by turning the flushknob in a clockwise direction. When flushknob is released it will automatically turn back.
- To flush after use, turn the valve knob in an anti-clockwise direction and turn the flushknob. This procedure results in the best bowl rinse and most efficient use of water. After flushing, turn the knob in a clockwise direction to close the valve blade. The toilet can also be used with the valve blade open, which allows the waste to go directly into the holding tank.
EMPTYING THE CASSETTE
The Cassette capacity is 20 liters and Should be emptied when the waste level gauge indicator goes from green to full red. The gauge does not begin to move from green to red until the tank is over ‘A full.
CAUTION: Do not allow Cassette to become overfilled, see the troubleshooting section for the emergency emptying procedure. To empty Cassette be sure that the valve blade is in the closed position. - Open the access door on the outside of the caravan and remove the Cassette tank by pressing the retaining dip.
- Carry the Cassette using the lower carrying handle, pour out spout up, to a normal household type toilet or another authorized disposal point. SE Cassette in a vertical position on the ground and rotate pour out spout upward.
- Remove spout cap. Grasp the unit by the upper carrying handles nearest to pour out the spout. Place another hand on the upper rear grip so that the air relic valve button can be depressed with the thumb while emptying, to insure smooth outflow of tank contents. When empty, remove the sliding COVE manually by sliding it towards the pour-out spout, rinse tank, and valve blade area with water.
Note: Depress air release valve button only when pour out spout is pointed downwards. - If necessary make the toilet ready for use (see nr. 1 up to nr. 7). Slide the Cassette into the toilet and lock the access door.
CLEANING AND MAINTENANCE
The large seal and the seal for the ventilation, frequently have to be cleaned and greased (depending on the frequency of use, once or twice a month), with silicon spray or salad oil Clean the Cassette by rinsing it very well with clean water. Clean the toilet bowl, seat and cover, and the toilet itself with a moist cloth. In case it is necessary use washing-up liquid or another mild soap. If the toilet is not going to be used anymore after cleaning, leave the cap off the pour-out spout so the Cassette can dry. WINTERIZING/STORAGE
The Thetford Cassette Porta Potti is easily winterized for storage or cold weather use. - Empty the freshwater tank using the drain tube. Position drain tube outward through the door opening. Pull off the plug and drain water from the tank.
- Flush a few times by turning the flush knob to drain the pump assembly.
Notice: Cassette has to be in. Empty the Cassette afterward. - Empty the water fill funnel by pulling the bottle away from the tank. Remove small water cap at fill bottom, allowing water to drain from water funnel.
NOTE: Do not tighten caps, this helps in keeping the unit dry.
COLD WEATHER USE
The Cassette can be used during cold weather when the caravan or motor home is heated. When the vehicle is not heated for more than a day (or a night) winterize the Cassette.
THETFORD WARRANTY
- The Thetford Cassette Porta Potti is warranted to the original buyer for one year from the date of purchase, provided the warranty card duly completed has been returned to us within 30 days after the date of pur-chase.
- The warranty covers the replacement of parts arising from defects and workmanship and from the inability of the unit to perform its intended function.
- In case of a defect apply to the original dealer or Thetford Service Centre with proof of purchase.
- Defects, which in our judgment occurred from misuse, negligence, or accident, are not covered by the warranty. In addition, the warranty does not apply if the product is installed or handled improperly or if other than the prescribed chemical agents have been used or if the product has been altered in any way or has been repaired by unqualified persons, or if the serial number and/or date has been altered or removed.
- Should the original buyer wish to return to us parts believed to be defective, the parts should be sent prepaid. If we find the parts defective and covered by warranty, they will be repaired and returned. If the warranty does not apply or has expired, a nominal charge will be made. Any transport costs are for the account of the owner.
- Before returning products or parts they should be cleaned, in order to carry out inspection and repair.
- No other warranty is given and no personal representative is authorized to make any warranty or assume liability by words or action under any warranty other than that is contained herein.

Please fill in the model, the number, and the code of your toilet in this space


TROUBLESHOOTING (Problems – Solutions)
- Bowl does not drain when the toilet is flushed. CASSETTE is overfilled.
DO NOT REMOVE THE CASSETTE. While inside the Caravan turn the valve knob anti-clockwise to open the valve blade and leave it in the open position. Open the access door on side of the Caravan. Rotate pour-out spout outward. Place appropriate size container under spout cap. Remove cap carefully. Allow bowl contents to drain into the container. This will lower the water level in the bowl. Replace the cap and return the pour-out spout to the stored position.
DO NOT REMOVE CAS-SETTE. Go inside the Caravan and turn the valve knob clockwise to close the valve blade. Now, the Cassette may be removed following the normal removal and emptying procedure. - Odors. Use the proper amount of holding tank deodorant specified on the bottle.
- Soiled bowl after flushing. Partially fill the bowl to cover a soiled portion of the bowl. The next flush will dis-solve waste.
TIP: Leave valve blade open during use. - CASSETTE cannot be removed. Check for obstacles under the retaining clip. Depress retaining clip several times to check operation. Remove CASSETTE. Valve knob and valve blade in the partially open position. Close valve blade by moving knob clockwise.
CAUTION: If the valve blade is open during CASSETTE removal, severe damage to the system can occur. Never force insertion or removal of the Cassette tank. - The valve blade mechanism sticks or is hard to open. Spray a light film of silicone on the blade.
- Major unit malfunction. Contact your original Caravan dealer.

EXPLODED VIEW (C4)

| part no. | description | |
| 1 | 16377* | Flush knob |
| 2 | 16194* | Seat & cover |
| 3 | 16183* | Hinge post/pin |
| 4 | 16381 | Waterfall funnel complete |
| 5 | 16385 | Drain cap/waterfall funnel |
| 6 | 16171* | Level indicator |
| 7 | 20292* | Flush tube |
| 8 | 21066 | Inlet tube |
| 9 | 21065 | Bellow |
| 10 | 20291* | Flush mechanism complete |
| 11 | 16350* | Clip & clip retainer |
| 12 | 16169 | Spring (retainer clip) |
| 13 | 2140174 2140274 | Holding tank R.H. Holding tank L.H. |
| 14 | 16196* | Pour out spout |
| 15 | 16384* | Dump cap |
| 16 | 16195 | Cap seal & spout seal |
| 17 | 16175 | Lip seal |
| 18 | 16193* | Seal cover & screws S |
| 19 | 21333* | sliding cover |
| 20 | 16176* | Vent plug |
| 21 | 2372274 | Automatic vent |
| 22 | 21528 | Seal automatic vent |
| 23 | 21458* | Blade opener |
| 24 | 16376** | Door complete 22/28mm wall |
| 25 | 16179 | Hinge pin door |
| 26 | 16382 | Door seals (2) |
| 27 | 21106** | Door complete |
| 28 | 21111 | Door seals (2) |
| 29 | 16388** | Door lock complete |
| 30 | 16199 | Door keys (2) |
| 31 | 21000** | Lock cover |
| 32 | 16831** | Lock complete |
| 33 | 16832 | Door keys (2) |
| 34 | 21108″ | Lock complete |
| 35 | 21109** | Lock cover |
| 36 | 21110 | Door keys (2) |
| 37 | 20325* | Mechanism complete |
| 38 | 16182 | Drain tube |

| Capacity freshwater tank | Capacity waste holding tank |
| 15 L | 20 L |
| Thetford B.V. Nijverheidsweg 29 P.O. Box 169 4870 AD Etten-Leur The Netherlands Tel.: 01608-15944 Fax: 01608-22429 | Thetford G.m.b.H. Schallbruch 14 42781 Haan Germany Tel.: 02129 – 50098 Fax: 02129 – 59898 | Thetford Ltd. Cantrell Industrial Estate Caldwell Road Nuneaton/Warwickshire CV11 4UD England Tel.: 0203-341941 Fax: 0203-641230 |



















