Toilet will not flush!!!!!!!!!!!!!!!!!

[mattbe30]

We have recently installed a new bathroom suite with a concealed toilet cistern on the ground floor of a customers property. the toilet, cistern, units have all been fitted to the exact manufactures requirements. one small problem the toilet doesnt cope with a couple of sheets of toilet paper let alone a good "FILLING" does anybody have any ideas on the cause of this?
we have stripped the toilet down and their seems to be no problems with the casting of pan. We have changed the flushing mechanism. My plumber's opinion is that this kind of system is prone to problems as there is no gravity to help push the water through the pan.. Any help will be greatly appreciated
one other thing the drains are flowing freely in the manhole.

 

[seco services]

sometimes the design of the pan don't help. flushing holes round the rim.

 

[buck51]

Hi has the flush pipe been pushed into the pan too far??? thus blocking off the two spreader holes which direct the flush arround the sides of the bowl

 

[mattbe30]

nah the pattern of the water spray around the bowl is fine, im wondering if a substack should have been fitted

 

[Hugh Jaleak]

Cant see how a stubstack would help. Is it blocking or just not clearing? With some W.C.'s the flush is not powerful enough to clear contents of the pan. Manufacturer/style of W.C. might assist with a diagnosis.

 

[mattbe30]

ive booked the manufacturers in