15mm DZR Single Check Valve WRAS Approved Compression Non Return

It's a good compression valve. It works fine. Is the same quality that you would buy in professional shops

works well

Purchased two of these. My kitchen and bathroom sink hot water is gravity fed and the cold is mains pressure. As a consequence, if both hot and cold taps are turned on together, the cold water flows into the hot water system. So to comply with water regulations I have fitted one to each hot water supply.Easy to fit after isolating the hot supply. Cut a small section out of each pipe and insert the check valve observing the flow arrow cast onto the valve body.

stopped my shower thermostatic valve back feeding the boiler when trying to drain it