Types of water softener,
explained.

Non-electric twin-cylinder softeners

These have two resin cylinders: one softens while the other cleans itself, so you always have soft water. They're driven by water flow, so they don't need a power socket, and they regenerate based on how much water you've used. Harvey's and Kinetico are well-known examples.

Electric softeners

Electric units use a small control valve, plugged into a socket, to decide when to regenerate. Some regenerate on a timer, others when they calculate it's needed. They're usually single-cylinder, so they regenerate when water use is low, typically overnight.

How some well-known brands compare

From each manufacturer's own website or installer handbook (October 2026). Ranges change, so check the current specification of the exact model.

With twin-cylinder softeners one cylinder softens while the other cleans itself, so you always have soft water. Single-cylinder electric units supply unsoftened water while they regenerate, which is why they're set to do it overnight.

Block salt or tablet salt

Some softeners take blocks of salt, which are tidy to handle and drop straight in. Others take tablet salt poured into a larger salt store. Which you use depends on the model. Either way, you'll top it up periodically.

Things to think about before choosing

Space: under a kitchen sink is the most common spot, but it isn't always big enough. A utility room or garage can work, as long as it's on the incoming main.

Power: if there's no socket nearby, a non-electric unit avoids the problem.

Drinking water: keep one unsoftened tap at the kitchen sink for drinking, cooking and baby feeds.

Fitting: a softener needs a bypass so it can be isolated, plus a non-return valve on the supply, and its drain and overflow run properly.

Upkeep: you'll top up the salt, and the manufacturer will recommend how often the unit should be serviced.

Already chosen one?

We can fit a softener you've already bought, or help you choose one that suits your home.