Ive been to a house which has a concealed cistern with an air switch operated syphon , the syphon works fine but the air pressure has broken , I have been to plumb center who said they cant get one , If I have to I will have to get a syphon with a cable on it and replace the whole thing i will it just involes removing the cistern to do it , it just seems a waste when all I need is the push button , anyone know who makes them or where I can get one from ??????????