Living with a noisy boiler is not only unpleasant, but it can also be inefficient. A number of factors can cause boiler noise, but it is most often caused by a thin layer of deposit on the heat exchanger. Sentinel X200 Noise Reducer is extremely effective in solving this problem, whilst simultaneously helping to restore boiler efficiency. Sentinel X200 1 litre boiler silencer provides a unique, life-long system treatment for the elimination of boiler noise, known as kettling". Its safe to use in all types of indirect central heating systems and will quickly pay for itself in reduced fuel usage. Eliminates boiler noise, Restores boiler efficiency, Safe and non-corrosive, No need to flush – stays in system