There are are over 12 different types of Thetford toilets so which one is yours?
if in motorhome its likely to be a c3 with electric valve working with the main pump in the inboard tank so you will have to contact Thetford for advice.
If it's the older C2 type electric pump with large knob on left [facing] which opens the blade in the pan and operates the flush then I've set up a help folder for this model as I've had so many requests for help from Uk and downunder in Australia.
If it's not this type then I can't help so here are contacts
www.thetford-europe.commail:
or if in Australia e-mail: info@thetford.com.au
Reason I've had a few help requests from downunder for my help file.
If it is the c2 then email robertwhiting76@hotmail.com
bob, February 2009