The Twin Sentinel S4- 4 Bar Water Boosting Bundle INSTALLATION & USE The Twin Sentinel bundle consists of a pair of 4-bar pumps supplied with two fully automatic fixed speed pump controllers with 0.4l potable expansion vessel. The Sentinel is suitable for a number of house water boosting applications and is specifically designed as a solution to low water pressure and flow. The pump is efficient and extremely quiet in operation. Ideal for boosting water pressure in large properties with up to 4 bathrooms . Twin pumps are designed to boost both hot and cold water supplies equally. Can Provide 30 litres per min at 4 bar. The Sentinel must be used in combination with a break tank or header tank. This will give your pump a reservoir of water to draw from. If you do not have a break or header tank, you may need to consider our All-In-One Solution water booster that comes complete with a water tank.Unless otherwise specified pumps are not allowed to be connected directly to the public ma