What does connecting a machine involve?

Three things: a cold water feed with its own small valve, a way for the dirty water to leave, and a socket within reach. A modern washing machine is almost always cold fill only, and a dishwasher the same, so the old hot feed under many kitchen sinks is no longer needed and can be capped off.

The water feed ends in a valve with a lever or a screwdriver slot, so the machine can be isolated without touching the rest of the house. The drain hose either hooks into a standpipe, an open vertical pipe with a trap at the bottom, or pushes onto a spigot on the sink trap. The socket and any new wiring are an electrician's work rather than a plumber's.

Why does the sink fill when the machine empties?

A machine pumps water out faster than a kitchen waste can always carry it. If the sink gurgles or rises every time the dishwasher drains, the pipework is partly blocked with grease and food, too small, laid without enough fall, or missing the trap it needs. A plumber can clear the run, re-lay it or give the machine its own standpipe so it no longer shares the sink waste.

If the water smells foul when it comes back up, the problem may be further down and involve the drain rather than the kitchen pipework.

Why does the hose drip?

Supply hoses are rubber or braided and they age. A hose squashed behind a machine for ten years can split, and the fittings at each end loosen as the machine vibrates. A drip that appears only during a wash is usually the drain hose or the standpipe trap. One that is there all the time is the supply hose or the valve. Both are quick to put right, and a plumber may suggest renewing a tired hose rather than waiting for it to go.

Pull the machine out now and again and look behind it. A slow drip behind an appliance can rot a kitchen floor long before it shows at the front.

Where can a machine go?

Anywhere with water, waste and power, though some rooms are easier than others:

a kitchen, where the sink waste is already close
a utility room or a garage, which may need new pipework run from the kitchen and protecting from frost
an upstairs cupboard, which needs a standpipe tall enough to stop the machine siphoning its own water back, and a tray beneath it for leaks
a bathroom, where the wiring rules restrict where sockets and switches can go, so an electrician must be involved before a plumber

In a flat, a machine draining into a shared stack must be connected properly, and the lease may say whether a washing machine is allowed at all. Check it before buying.

Which hoses and valves are suitable?

Everything connected to the mains supply in England has to meet the Water Supply (Water Fittings) Regulations 1999, which exist to stop water being wasted or the supply being contaminated. For appliances, that means a sound connection with backflow protection appropriate to the machine, hoses of an approved type and a valve that shuts the feed off. A plumber working to the regulations will supply those parts. If you are using the hoses that came with the machine, keep the paperwork.

Can the plumber fit the machine itself?

Usually, if it is on site and the plumbing is ready. Levelling the machine, removing the transit bolts from a new washing machine and fitting the hoses are quick jobs, but say in the enquiry that you want them done, because some plumbers prefer to leave the appliance to the retailer. An integrated dishwasher that sits behind a kitchen door is a joinery job as well as a plumbing one.

What should I check before the visit?

that there is a socket within reach of where the machine will stand
whether the water feed already exists and has a working valve
where the nearest waste pipe or sink trap is
the depth of the space, allowing for the hoses behind the machine
for a utility room or garage, whether pipes will be exposed to frost
for a flat, what the lease says about appliances and shared pipes

What goes in the enquiry?

Your postcode, which machine it is, whether it is a new connection, a move or a repair, and which room it is going in. If something is already leaking, say whether you have turned the valve off. If the machine has not arrived yet, give the date it is due.

Who you will hear from

We pass your enquiry to one local plumber, if one covers your postcode. It is never sent to a list of companies. If nobody covers your postcode, we will tell you and will not pass your details on.