Auwii T1 T2 T3 T4 Cooling Laboratory Circulator Industrial Chiller Pump. US$ 1413-1730 / Piece. (FOB Price) Our circulating pump is on its way out I've tried bleeding it, etc but it's still whirring so it looks like the impeller is shot. Either way, I could replace it for another CP53 at £40 but everyone online seem to go for Grundfoss. The Grundfoss 15/150 is recommended as a CP53 replacement: 489 products. Circulating pumps move water through pipe systems to deliver hot water to faucets and shower heads, or to provide radiant heat to floors and radiators. They conserve water by delivering hot water faster than gravity-fed systems. Potable circulating pumps operate in an open loop system where drinkable water exits the pipes for use. Buy the Potterton Cp53 Pump Envoy System from Direct Heating Spares. DHS Part Number: 1122838 - Manufacturer Code:411151. We have over 20,000 items in stock and available Next Day. Free Boiler Manuals also available to download.