The toilet has had quite a makeover over the last few years, and not just in the looks department. The inner workings of the cistern have really joined the 21st century. The newer designs will not hold all the flushing arrangements that were in the older cisterns, so instead of the traditional siphon etc. the inlet valve is either a modified diaphragm type with a very short float arm, and miniature float, or an ingenious vertical valve with a float cup that fits round the central column of the valve body. These are both really quiet as they operate, but the float cup is slow to fill the cistern if it comes from a storage vessel rather than mains supply. The flush is also operated by top fitted button in the cistern lid. A Bromley Plumber is a trained professional. This design incorporates an overflow. Now, the button is split into two, with one for a short low volume of water flush and the two together is for a high volume flush. The button is connected to the plunger rather than the older style wire link float arm system. The valve design is very clever but can be very tricky to make adjustment for a correct fit so when installing the valve must be adjusted so that the critical level on the body of the valve is at least 25mm above the top of the overflow pipe. There is a threaded shank at the base of the valve assembly which gives the relevant adjustment so that correct positioning can be achieved. Bromley Plumbers can fit the new modern WC systems.The float cup inlet valve is a rubber ring seal at the bottom of the cistern which will probably need replacing in time but, spares are available. It is recommended that you keep any documentation regarding the unit such as a diagram should you need to replace a defective seal at some point.