How to install a washing machine and plumb it in

Check the space before the machine arrives

Most installations that go wrong do so because the connections are not where the machine needs them. Look at the space before delivery day. You need a cold water supply with an isolating valve, a waste connection the drain hose can reach, a socket nearby and a floor that is solid and level.

The standard washing machine valve in the UK is a small tap on a 15mm pipe with a threaded outlet that the inlet hose screws onto, usually with a blue lever for cold and red for hot. Most modern machines are cold fill only, so you will use the blue valve and leave any hot one turned off. The waste is normally either a vertical standpipe with its own trap, or a spigot on the side of the kitchen sink trap.

• A cold water valve within reach of the inlet hose, that you can turn on and off
• A standpipe or sink waste spigot within reach of the drain hose
• A socket that is not behind the machine and not on an extension lead
• Enough depth behind the machine for the hoses to bend without kinking
• A level, solid floor that will not flex when the drum spins

Step 1: remove the transit bolts

New washing machines are delivered with transit bolts, usually three or four, screwed through the back panel to stop the drum moving in transport. They must come out before the machine is used. Running a machine with them in can damage the drum, bearings and suspension within one spin cycle, and manufacturers generally do not cover that damage under warranty.

Undo them with the spanner supplied, pull out the bolts and their plastic spacers, and push the plastic caps from the accessories bag into the holes. Keep the bolts somewhere safe, because you need them again if you ever move house with the machine.

Step 2: connect the water supply

Check the rubber washer is sitting inside each end of the new inlet hose. Screw the angled end onto the back of the machine and the straight end onto the cold water valve. Tighten by hand until firm, then a small extra turn. Overtightening with a spanner can split the plastic fitting or crush the washer, and both cause leaks later.

Always fit the new hose that came with the machine. An old hose that has been squashed behind a machine for years is one of the most common causes of a flood, and our guide to a flexible tap hose leak explains why these hoses fail. If the valve is stiff, weeps from its spindle or will not turn off, have it replaced before connecting anything.

Step 3: connect the waste

There are two usual ways to connect the drain hose, and which one you use depends on what is already there.

Waste water from a washing machine must go to the foul drain, never to a rainwater gully or surface water drain. A new waste run through an outside wall needs to join the right drain, which is worth having a plumber check.

Step 4: position, level and test

Slide the machine into place slowly, watching the hoses so they are not trapped, kinked or stretched. Put a spirit level on top and adjust the feet at the front until it is level side to side and front to back, then lock the feet with their nuts. A machine that is not level will walk across the floor and bang during the spin.

Plug the machine in, turn the cold valve on and check both ends of the inlet hose straight away. Then run a short rinse or empty hot wash with nothing in the drum. Stay nearby and check the inlet connections, the drain hose at the standpipe or spigot, and the floor underneath, both while it fills and while it pumps out. If the sink gurgles or water backs up into it when the machine drains, the waste run or trap may be partly blocked.

When installing a washing machine needs a plumber

A like-for-like swap into a space that already has a working valve and waste is within reach of most people. Anything beyond that involves cutting into pipes, adding a trap or running new waste, and a mistake there can flood a kitchen or a flat below.

• There is no washing machine valve, or the old one leaks or will not turn off
• There is no standpipe or spigot, or the drain hose will not reach it
• The machine is moving to a new room, such as a utility room, bathroom or cupboard
• Two appliances need to share one waste
• The sink gurgles, drains slowly or smells when the machine empties
• You live in a flat and a leak would affect the neighbours below

Self-cutting valves and quick plumb-in kits

DIY shops sell self-cutting washing machine valves that clamp onto an existing copper pipe and pierce it as they are tightened. They can work, but they depend on the pipe being the right size and in good condition, and they leave a small hole in the pipe with nothing but a seal holding back mains pressure. A proper tee fitted into the pipe with a separate isolating valve is the more reliable way to add a supply, and it is a short job for a plumber.

Washing machines approved for UK use normally have the required backflow protection built in, but the supply fitting and pipework still need to meet the water fittings regulations. Our guide to planning washing machine and dishwasher plumbing covers what a new connection should include, and how to disconnect a washing machine explains the reverse job when you are taking an old machine out.

Book a washing machine or dishwasher connection

If your new machine needs a valve, a waste, or a new location, Loyal Plumbers can do the plumbing across London and everywhere inside the M25. We run 10 vans, 24 hours a day, and our call-out charge is £60. We can also fix a leak from an existing installation, or sort out a waste that backs up into the sink.

When you get in touch, tell us where the machine is going, what is there now, whether the space already has a valve and a waste, and send a photo if you can.