Lifescience WK4 scale reducer 68-108mm

Scale reducers fit into the cold water pipework to cut the limescale that hard water leaves in boilers, water heaters, showers and appliances. Unlike a water softener, they do not take the hardness out of the water and use no salt; they change how the hardness behaves so less scale sticks to hot surfaces. This category covers electrolytic, magnetic and polyphosphate scale reducers for 15mm and 22mm pipe, with compression or push-fit ends.

Types

• Electrolytic: alter the structure of the hardness salts so they are less likely to form hard scale. Fitted on the incoming cold main, one unit can protect the whole house.
• Magnetic: protect a single appliance. The effect fades as water travels, so fit the unit on the cold feed no more than about a metre before the boiler or heater it protects.
• Polyphosphate: dose a small amount of food grade polyphosphate into the cold feed to a combi boiler. The cartridge is changed every year, which can be done at the boiler service, and the unit must sit at least a metre from the boiler.

When you need one

In England, Approved Document L defines hard water as more than 200 ppm total hardness. Before a new boiler is fitted in a hard water area, it expects the feed to water heaters and to the hot water side of combination boilers to be treated to reduce limescale. Choose a WRAS approved unit, match the pipe size and end type, and install it in the position and orientation the maker specifies. Work on the boiler itself and its gas parts must only be carried out by a Gas Safe registered engineer.

To remove hardness altogether, see water softeners, or browse the wider water treatment range.