if looking back in for more replies follow the info below. from what you say sounds like the flush pipe is off or there is no water in tank as bill cox says.
If you want to go manual have word with Thetford under 'Ask thetford' If your's is a C2 with the toilet roll holder to right(facing toilet then the cup that holds the roller removed is where you would refit the manual flush, it's same size as the elec flush knob other side that stays in place.
uk & europe www.thetford-europe.com
australia www.thetford.com.au (even get request from australian campers)
australia site has stockist list.
home page select english {if in australia forget this selection it doesn't come up)
select customer service (top line)
select products from top line
select bulit in or portable which ever applies.
select user information from list on right.
select repair instructions from list on right
select built in or portable which ever applies.
select select your toilet series model number from right list.
you will now be in the pdf listings for your range of toilets just select those that apply to your toilet and down load them they're free.
as you go through watch for 'ask thetford' on left listings
you may not find what you want and you can send them a message.
for safety reasons which i agree with thetford do not offer repair advice for fridges. refer to service centre
bob
November 2011
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix camping equipment.