solutions:This refers to the C2, 3 and 4 bench style toilet so would have been clearer to quote the model.
While the blade (the hatch cover) is in the closed position remove and clean out the cassette. Once cleaned slide blade cover to reveal the blade there is a knob near it on the cassette turn this anti clockwiase to open the blade if its tight the problem my be build up on the seal. Get new seal and while at it a telescopic magnet on a stick to recover any screws you may drop removing the cassette seal screws. These seals are dated so check date of caravan when purchasing there is a difference in design. Fit new seal then see if the blade opens easy by hand. refit slode off blade cover and push cassette back in to the caravan try operating the blad/flush knob.
If its not the above type contact
Thetford on www.thetford-europe.com send them message of the problem.
Remember there are several model so look up your one if not the bench type above.
bob uk, May 2017
