Buying a house with a water softener: what to check

Spring's a busy time for house moves, and in London a fair few of the homes changing hands come with a water softener tucked under the sink or in the utility room. That's usually a nice bonus. But a softener nobody's looked after for years isn't quite the same thing as a working one, so it's worth knowing what to check.

Here's a practical list for the viewing, the paperwork and your first few weeks in the new place.

At the viewing

You won't be able to do a full inspection, and you don't need to. A few quick looks will tell you a lot.

• Find it. Usually under the kitchen sink, in a utility room, garage or cupboard near the stopcock. If you can't see one, ask.
• Look at the taps and shower screens. If there's a softener and it's working, you shouldn't see much limescale on the softened taps. Heavy scale everywhere suggests it isn't doing its job (or isn't plumbed to those taps).
• Peek in the salt compartment if the sellers don't mind. A softener with salt in it is at least being looked after. An empty or rock-hard salt tank is a clue.
• Check for a separate drinking tap in the kitchen. Most properly fitted softeners have one, giving unsoftened water for drinking and cooking. If there isn't one, it's something to sort after you move in.
• Look for leaks or damp around the unit, the pipes and the cupboard floor.

Questions to ask the sellers

Your conveyancer will send the sellers a fixtures and fittings form, but it's worth asking a few softener questions directly, either at the viewing or through the agent:

• Is the softener staying with the house? (Normally yes, but confirm it's listed as included.)
• What make and model is it, and roughly how old?
• When was it last serviced, and by whom? Is there any paperwork or a service record?
• Was it ever rented or on a finance or maintenance plan that needs ending or transferring?
• Which salt does it use, and how often do they top it up?
• Do they have the manual, or know where the bypass valve is?
• Has it had any problems or repairs?

Don't worry if the answers are vague. Lots of people use a softener for years without knowing much about it. But a seller who can show you a recent service record is a good sign.

Do you even want it?

Worth a thought. In most of London the water is hard, so a working softener is generally a plus: less limescale, less cleaning, and protection for the boiler and appliances. Our post on limescale and your boiler explains why.

If you'd rather not have one, a plumber can remove it and reconnect the pipes. That said, if you're unsure, it's often worth living with it for a few months first. Plenty of people only realise how much they liked soft water when it's gone.

Your first few weeks

1. Find the bypass valve

Every softener should have a bypass that takes it out of the loop while keeping your water running. Find it, and figure out which position is "service" and which is "bypass". If you ever get a leak from the softener, that's the first thing to turn.

2. Check it's set to softening

It's surprisingly common for a softener to be left in bypass after a previous repair, so the water's been hard all along. If the valve's in bypass, switch it back to service.

3. Sort the salt

Work out which salt it uses and get some in. Our guide to block salt, tablets or granular will help if you're not sure. Check for a salt bridge (a crust with a gap underneath) by gently pushing a broom handle down into the salt.

4. Test the water

Grab a cheap hardness test strip and test two taps: a softened one (like the bathroom basin) and the kitchen drinking tap. The softened tap should read at or near zero and the drinking tap should read hard. If they both read hard, the softener isn't working, or isn't connected the way you think.

5. Check the drinking water set-up

If there's no separate unsoftened drinking tap, get one fitted early on, and treat it as a priority if there's a baby in the house, because NHS guidance says not to use artificially softened water for making up formula. In the meantime, one stopgap is to put the softener into bypass, run the kitchen cold tap for a minute or so to flush the softened water out of the pipe, then fill the kettle. We explain the sodium side of things in can you drink softened water?

6. Book a first service

Unless the sellers can show you a recent service, it's a good idea to have it looked over. An engineer can test the water, set the softener up for your household (which may be very different from the last one), clean it out and spot anything that's worn. Our servicing page explains what's involved, and we work on all the major brands, not just ones we've fitted.

When it's worth replacing

Old softeners can run happily for a long time with a bit of care. But if yours needs expensive parts, has a resin bed that's past its best, or is far too big or small for your household, replacing it can make more sense than repairing it. A good engineer will tell you straight which way they'd go. If you do end up looking at a new one, our installation page covers the options.

And if something's already not right, our troubleshooting checklist and our guide to how often to service a softener are good next reads.

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