As we continue preparing the motorhome for our travels, in September 2017 I bought a brand new SOG unit from eBay for £112 including P&P saving £10
Our cassette toilet is a Thetford C200.

SOG charcoal filter cover
The SOG unit does not require any chemical toilet fluids like Aqua Kem Blue and Pink toilet flush, therefore a SOG unit will pay for itself because you don’t have to buy any chemical fluids.
It operates when you open the cassette toilet blade inside the bathroom, this action powers the small extractor fan, 12 volts, and draws the smell and oxygen through the flexi hose to the charcoal filter fixed to the outside. This action also breaks down the solids naturally. The valve ensures the smells are pushed outside and not back inside the van.
Benefits are:
- chemicals are not used so therefore this environmentally friendly
- no further costs, i.e. no need to purchase chemical fluids
- easy enough to install if you take your time
- the cassette toilet can be emptied in both chemical disposal points on camp sites and in standard toilets (please clean up though and keep motorhomers reputations intact)
- no requirement for special toilet tissue paper, continue to use normal toilet tissue paper
Of course we all make our own choices but we are pleased with the SOG unit.
Installation and fitting I did myself and took about an 90 minutes, the instructions are comprehensive with photos.
I did the wiring first, no drilling yet, joined the spade connections and tested to ensure the unit works before fitting. All ok, now;
- Remove the toilet blade mechanism, 4 screws, approached through the outside cassette door.
- Next was to carefully saw, cut and sand the plastic blade part as per the instructions.
- Now put this back in to the same position it came from.
- Place the metal bracket with the micro switch in position, flick the switch with your finger ensuring it’s still working correctly.
- Mark the position for the metal bracket, drill a 5mm hole through the toilet plastic white casing, it will go through in to the bathroom, this is normal.
- Now inside the bathroom push the plastic pop rivet through the hole to meet the pre-drilled hole in the metal bracket, there are self sticky pads on the metal bracket as well to hold it in a permanent position.
The scary bit now, with a hole saw (20mm I think) drill a hole in the white plastic outside cassette door. Fix the fan using 4 screws to the inside of the door pushing the fan neck in to the new hole, connect the wires together, gently push the black flexi hose on the green plastic neck on the cassette and the other end of the pipe on the fan.

Fitted and working
Test the closing & opening of the door, flick the blade switch with your finger to test, then pop inside the van and test the blade mechanism, all working? perfect!
Dave