It should be under a 2 year guarantee therefore take it back to the supplier. Alternatively it can only be the micro switch, capacitor or rubber boot on the electrical power unit inside the vessel. Remove the complete unit and take the lid off. Then remove the motor and power pack. The power pack is easy to dismantle after taking the rubber boot off the bottom. You shall see the capacitor (looks like a short white tube) inside. The micro switch is a very small black rectangular part.
To order these parts call Saniflo head office on 02088420033.(UK). This shall save you buying a complete new unit at £270 plus.
Peter
May 2009