Thetford motorhome toilet problem? Help is here.

A loo was one of the main features that we wanted in a motorhome, it gives us the ability to stop anywhere and not worry about where we can ‘go’. But after a while a frequently used loo can develop a problem, and if you’re in a foreign country miles away from a motorhome dealer it isn’t funny.

Luckily the sticking blade on our loo was sorted by a good old clean and lubricate, but while I was looking for solutions on the internet I found this really useful document from Thetford. It explains how to repair the most common toilet problems. Please download a copy and store it somewhere safe as you never know when you might need it.

Download (PDF, 12.67MB)


  1. Did you ever try using the biological washing tablets? All the solids break down to a slurry and if you have Liquid Bio in your flush tank it helps keep the blade clean. It’s cheaper and probably easier to find then the proper stuff.

    • Hi Mark. Tried bio liquid which works up to a point. The matter all breaks down OK, but in high temperatures it niffs a bit, especially when it’s agitated by a twisting road and when we’ve been enable to empty it for a week or so. Also we don’t have a separate flush tank, it’s a feed straight from our fresh tank, so I guess that’s not helping. On the whole it works very well, massively cheaper than official chemicals but next time I’m fitting a SOG unit! Cheers, Jay

  2. For some reason we haven’t had a chance to test it in the heat, something to do with staying in this country!! Thought you had a separate tank but you can always dilute the liquid bio and stick it in a squirty bottle.

  3. I have a leak from the in side running down to the back were you pull out for empting it i do believe it could be a lose hose connected to the flushing system.

  4. The shaft on the theft ford 403c has broken how do I get the toilet out to replace it isn’t possible from the top as its all enclosed

  5. Hello

    We have returned to our caravan and the toilet had leaked from the bottom, we have pulled the Thetford cassette out cleaned and checked it has no split etc which it doesn’t. It’s like the waste has rested on the top of the cassette and then come back through the floor, is this normal? The caravan is only a year old and so is the toilet.

    • Hi Joanne
      Sorry, but that’s not a problem we have experienced, so we can’t really help. Hopefully the Thetford toilet instructions will shed some light.
      Ju x

  6. Hi, when I empty the cassette all this brown liquid comes out, I only use it for #1…Just replaced the cassette with a new one and it is still doing it.. would it come from the rinse tank…and it also comes on the floor of the shower recess….Just don’t know what to do…

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