Regulations.. It is important to ensure that the water supplies to your taps and mixers are connected in accordance with the water regulations (WRAS) requirements and good plumbing practice. It is Peglers recommendation and good plumbing practice that the supplies of hot and cold water to the mixer should be at equal (balanced) pressures in order to provide a consistent flow. Supplies should be from a common source, either mains or tank fed. If supplies are not equal pressures then non return valves should be fitted. Pegler Product Code - 4K4001. Pegler 10 Year Guarantee. (PRICE INCLUDES VAT & FREE DELIVERY).