Gravity Fed or Low Pressure water systems are one of the most common types of hot water system in the UK, and are often found in older houses.
Mains water is fed directly into a large cold water storage tank, which is usually located within a loft or roof space. As the cold water tank fills up, gravity allows water to be fed to the hot water cylinder below, where the water is then heated by an immersion heater within the tank or a back boiler.
Gravity continues to feed water from the cold tank above, creating the pressure needed to push the heated water from the hot water tank.
As this system relies on gravity to push the water down and create pressure, a gravity fed system typically delivers a low water pressure, although there are showers in the market that can counteract this and deliver an exceptional performance.