It will be the water chamber at the back of the dryer.
Either the float valve is not working or the pump that pumps up excess water from the chamber has stop working.
Float with valve is a easy DIY job and cheap to fix,pump is expensive at £49 and not really DIY,I have just fixed my daughter's and also did a float repair on previous machine.
Good thing is Hotpoint and Indesit condensor dryer parts are interchangable.
Steve, November 2017
