Washing machine and dishwasher hoses: the leak most people miss

You load the washing machine and the dishwasher, switch them on and forget about them. Yet behind them is one of the most common causes of escape of water in UK kitchens and utility rooms. Not the appliance itself. The hose.

A hose that bursts makes an obvious mess. The more common problem is quieter: a connection that weeps a few drops at a time, or water running down behind the kitchen plinth where nobody looks. Leaks like these can go on for a long time before anyone notices.

Here we look at why appliance hoses are so vulnerable, which signs to watch for and what you can do about it.

Why the inlet hose is the weak point

The inlet hose carries water into the appliance. It is connected to an isolation valve on the supply pipe, and as long as that valve is open, the hose is under full mains pressure. All the time. Even when the machine is switched off, while you sleep and while you are on holiday.

That makes it a weak point for several reasons.

• Rubber ages. Over the years rubber hardens and becomes brittle. It can crack or start to weep at the connections.
• The hose gets kinked. When the machine is pushed back against the wall, the hose often ends up in a tight bend. That spot wears and can eventually give way.
• Connections work loose. A washing machine vibrates on the spin cycle. A dishwasher gets pulled out and pushed back for servicing. Every movement can loosen a fitting a little.

Once something fails, it leaks around the clock too.

The drain hose and the leak behind the plinth

The inlet is the biggest risk, but the drain hose can leak too. It is usually connected to the trap under the kitchen sink or to a standpipe. The connection can be loose, the hose can slip out of its clip or the trap can be blocked so water backs up. The drain hose only carries water while the machine is pumping out, so a leak there only shows during or just after a cycle.

An integrated dishwasher is especially tricky. It sits between the kitchen units with a plinth in front. If something leaks, the water often runs down behind the plinth and spreads under the units and into the floor. Chipboard carcasses soak it up and laminate swells. By the time you notice anything, the water has often been running for weeks.

Warning signs your dishwasher or washing machine is leaking

Keep an eye out for these, in the kitchen and in the utility room.

• Damp on the floor or the plinth. Damp patches in front of the machine, or a soft plinth.
• Swollen units or flooring. Unit sides and plinths that have swelled, laminate lifting at the joints or wooden flooring starting to cup.
• Marks on the hose. Splits, bulges, discolouring or corrosion at the connections. Limescale around a nut usually means it has been dripping there for some time.
• A musty smell. A damp smell in the kitchen that cleaning does not shift.
• Water in the base tray. Many dishwashers have a base tray with a float switch. If there is water in it, or the machine stops with an error code, there is a leak somewhere.

If you see any of these, turn off the isolation valve for the appliance and find out where the water is coming from.

A simple inspection you can do yourself

You need no tools for this. It takes about a quarter of an hour and is worth doing once a year.

1. Turn off the valve. Close the isolation valve for the appliance before you move it.
2. Pull the machine out. Gently ease it forward so you can see the whole hose, without pulling on the hoses.
3. Check the full length. Look for splits, bulges, sharp kinks and worn patches from valve to machine.
4. Feel the connections. Wipe a dry piece of kitchen roll around each nut. If it comes away damp, it is leaking.
5. Test the valve. Open and close the isolation valve. It should turn without sticking and should not drip at the spindle.
6. Check the floor. Look at the floor under and behind the machine for stains, discolouring or swelling.
7. Run a cycle. Open the valve again, push the machine back without kinking the hose and keep an eye on it as it fills and drains.

When to replace washing machine hoses

There is no exact age at which a hose has to be replaced. Even so, many manufacturers recommend replacing hoses at regular intervals, so check the manual for your appliance.

Replace a hose straight away if you see splits, bulges or corrosion, or if it is old and you do not know when it was last changed. A new hose costs very little compared with water damage in the kitchen.

A few things are worth thinking about while you are at it.

• Choose a braided steel hose. A hose with a braided stainless steel outer layer stands up to wear better than a plain rubber one.
• Turn off the valve when you go away. Close the isolation valves for the dishwasher and washing machine before a trip, so the hoses are not under pressure while nobody is home.
• Stand the machine on a drip tray. A drip tray under the washing machine catches small leaks and makes them easier to spot. Many dishwashers have something similar built in.

This matters even more if the house is often empty. We cover that in our guide to protecting an empty home from water leaks.

How a flow monitor finds the leak you cannot see

All the advice above relies on you remembering, and on you being at home when something happens. A hose that starts leaking the day after your check can carry on until the next one.

This is where a monitor on the incoming water supply makes a difference. Water Grip clamps onto the mains water pipe where water enters your home and measures the flow continuously. Anyone can fit it in a few minutes, with no plumber needed.

Because the inlet hose is always under pressure, a leak there shows up as a small but constant flow. Water keeps moving even when nobody is using any, for example in the middle of the night. Water Grip recognises this as abnormal flow and sends an alert to the app. It does not matter whether the leak is behind the plinth, under the units or inside a wall. You hear about it anyway, wherever you are.

Water Grip does not turn off the water itself. When the alert comes, you turn off the stopcock or the isolation valve for the appliance. If you are away, you can ask a neighbour to do it.

Floor sensors under the appliances are another option, but they only raise the alarm once water has reached the sensor. You can read more about the difference in our comparison of a whole house leak detector vs floor sensors.

In summary

When a dishwasher or washing machine leaks, it is usually the hose or its connections. The inlet hose is under mains pressure all the time, so a leak can run unseen day and night, especially behind the plinth of an integrated dishwasher.

Check the hoses once a year, replace old or damaged ones and turn off the valves when you go away. To hear about a leak straight away rather than weeks later, a monitor on the incoming water supply is the simplest way to keep an eye on what you cannot see.