Sentinel combi guard 15 mm

Water treatment covers products that protect heating systems, boilers and appliances from corrosion, sludge and limescale. The range includes magnetic system filters, central heating inhibitors, cleaners, leak sealers and noise reducers, flushing equipment, water test kits, limescale reducers and water softeners.

Central heating systems

BS 7593 is the code of practice for water treatment in domestic heating systems. When a new boiler is fitted, the system should be chemically cleaned and flushed with fresh water, then dosed with an inhibitor that protects against corrosion and scale, and an in-line filter fitted. Check the inhibitor level regularly with a test kit and top up when needed. Leak sealers and noise reducers treat specific faults rather than replacing an inhibitor. Match a filter to the pipe size, commonly 22mm or 15mm.

Limescale and hard water

In England, building regulations guidance recommends treating the water feeding combination boilers and water heaters where hardness is above 200 parts per million, to slow the build-up of limescale. Options include electrolytic or magnetic scale reducers, polyphosphate dosing, scale inhibitors and water softeners.

Water softeners

Ion exchange softeners take hardness out of the water and are topped up with salt. Keep an unsoftened cold tap for drinking, usually at the kitchen sink, and do not use softened water to make up baby feeds. Fit a bypass valve so the softener can be isolated. Softeners and other fittings on the mains must be suitable under the Water Supply (Water Fittings) Regulations 1999.

Work on gas boilers and their gas parts must only be carried out by a Gas Safe registered engineer. Follow the manufacturer's instructions and safety data for all treatment chemicals.

For filters by type, see central heating filters; for whole-house softening, see water softeners.