I am assuming you are new to camping!
I've search the net using the model and conclude from this its a Thetford C4 bench type same as the one in my caravan. If it is then it has its own water tank and you will find this out if you go on to www.thetford.com.au or www.thetford-europe.com Ive put both incase the Ausy site don't work. Any way when your in look for service top line click then click repair istruction click sanitation first one then download the free pdf enter in the page search of down load the model c4 see if its yours then take it from there. Remeber the pdf covers all of their models not just one. MY other thougtht is your new to it as the cassette housing is where the fill funnel is for its own water tank, takes about 15 litres. One tip ALWAYS ensure the blade in the bottom of the bowl which closes the cassette is always IN THE CLOSED position or (a) you can't remove the cassette or if you manage to you break the blade closer shaft. And always drain off the flush tank when long pauses (2Months+) between trips to prevent lime build up on pump.
Here is one NZ supplier I've found. good luck.
Bob U.K
www.lewisgray.com
Office Location
40G William Pickering Drive, Albany
Auckland 0751, New Zealand
Postal Address
PO Box 302060, North Harbour
Auckland 0751, New Zealand
Contact Numbers
Toll Free (NZ Landline only): 0800 17 18 17
Phone: +64 9 415 3348
Fax: +64 9 415 3396
Bob U.K., October 2012
