My Turboflush T12 not flushing properly?

My Turboflush T12 is not emptying the water from the pan when it flushes.. If I switch the unit off at the mains then switch it on after I have flushed the WC it will empty but then the motor seems to be running slowly all the time. Could it be the time switch or possibly the pressure switch ?? If it is either of these where can I get replacement parts.