DIY GUIDE · PLUMBING & HEATING · CHECKED OCTOBER 2026
How to plumb in a washing machine or dishwasher yourself
An hour or two. £2–£25 for a new valve, hose or standpipe trap if the old ones are tired.
An existing valve, an existing waste, an existing socket. Three connections, then level it and check it twice.
- Every step, start to finish
- Checked October 2026 — sources at the end
- Honest about when to call a pro
FIRST, THE HONEST ANSWER
Do it yourself, or get a plumber?
Do it yourself if…
- There is already an appliance valve, usually a blue or red lever on a pipe behind the space
- There is already a standpipe, or a spigot on the sink trap, for the drain hose
- There is a socket within reach of the plug that is not behind the machine's back panel in a wet spot
- The new machine goes in the same space as the old one
Get a pro if…
- There is no valve and one has to be cut into the supply pipe
- The waste has to go through a wall, or the standpipe or trap is cracked or leaking from the wall
- There is no socket and a new one is needed, or the only socket is behind the sink
- Moving the machine means moving a gas cooker or its pipe
Safety first
- Unplug the old machine and turn its valve off before you pull it out. A washing machine full of water is heavy, and a fill hose torn off a live valve floods the floor.
- Washing machines are heavy and awkward. HSE's manual handling guidance is to avoid lifting what you can slide; walk the machine out on its feet, with a second person, rather than lifting it.
- Never plug a washing machine into an extension lead or a multi-way adaptor. It draws a high current for long periods and a lead heats up behind the machine where you cannot see it.
- If a gas cooker or its flexible hose is in the way, leave it. Disconnecting and reconnecting a gas appliance is gas work for a Gas Safe registered engineer.
- Remove the transit bolts from a new washing machine before it is switched on. Spinning with the drum locked wrecks the machine and can walk it across the floor.
Stop here: Stop here: new supply connections, new drainage, new sockets and gas
Teeing a new appliance valve into the supply is installing a water fitting, and it must meet the backflow rules in your nation: the 1999 Water Fittings Regulations in England and Wales, the Scottish Water byelaws in Scotland, and Northern Ireland's 2009 Water Fittings Regulations. A new waste connection is drainage work under the building regulations of each nation. A new socket in a kitchen is not notifiable in England unless it means a new circuit, under Part P; in Wales, its own Approved Document P makes work in a kitchen notifiable; Scotland works to building standard 4.5 and the wiring regulations; Northern Ireland has no Part P-style notification but the work still needs a competent electrician. Disconnecting or reconnecting a gas cooker is gas work, restricted to Gas Safe registered engineers under the 1998 Gas Safety (Installation and Use) Regulations in Great Britain and the 2004 Regulations in Northern Ireland. How to hire a kitchen plumber →
| MATERIAL | COVERAGE | FOR THIS JOB |
|---|---|---|
| Fill hose | The one supplied with the new machine | One, or two on a hot-and-cold machine |
| Appliance valve | Only if the old one leaks or is seized; compression or push-fit to match the pipe | One |
| Standpipe trap or twin connector | Only if the old one is cracked, or two machines share it | One |
| Jubilee clip | For a drain hose on a sink trap spigot | One |
How far the drain hose goes into the standpipe
Hose inserted = no more than the maker's limit. One maker sets 15 cm; with a standpipe 60 cm tall, the hose end sits 45 cm above the floor of the trap, clear of the water.
Pushed further, the hose end sits near the trap water and the machine can siphon: it drains while it fills and never finishes a cycle.
The appliance's instructions list a water pressure range. One maker's washing machine instructions we checked ask for at least 0.2 bar and no more than 10 bar. Mains-fed kitchens are nearly always within that. A machine fed from a low-pressure tank supply, unusual but possible in an old house, may fill slowly or not at all.
New machines come with new fill and drain hoses, and the makers say to use those or genuine spare hoses only. Throw the old machine's hoses away with it. A fill hose spends years under pressure and the rubber inside perishes; it is the commonest cause of a kitchen flood.
An appliance valve has a half-turn lever: in line with the pipe is open, across it is shut. If yours is stiff, weeping or green with corrosion, change it while the water is off. A replacement on an existing pipe end is a compression fitting, the same joint as a tap connector. A valve that has to be teed into a pipe is a different job, and is in the stop list.
The drain hose goes either into a standpipe — a vertical pipe with its own trap — or onto a spigot on the side of the sink trap. Both work. A standpipe is less likely to back up into the machine when the sink is full. If two appliances share one standpipe, a twin connector lets both hoses in without one draining into the other.
A built-in dishwasher sits behind a kitchen door panel and fixes to the worktop. Its hoses run to the next cupboard, usually under the sink, through a hole in the side panel. Check the hole is big enough for the hose ends before sliding the machine in, and keep the door-panel template that came in the box.
THE PART THAT DECIDES THE FINISH
Before you start — the space you are working in
What is behind the old machine decides how quick this is. Pull it out, look with a torch and find your case.
Freestanding machine, valve and standpipe already there
The everyday swap.
- Unplug the old machine, then turn its valve lever across the pipe
- Drain the old machine through its filter flap into a tray before moving it
- Walk it out on its feet, rocking side to side, with a towel under the front edge
- Clean the floor and check the valve and standpipe for drips while you can see them
Drain hose onto the sink trap
The hose clips onto a spigot on the side of the trap under the sink.
- Check the spigot is open — new traps come with a blanking cap inside it, which has to be cut or removed
- Check the trap is not cracked and its nuts are hand tight
- Run the hose up as high as the underside of the worktop before it drops to the spigot, so dirty water cannot run back into the machine
- Clip it with a jubilee clip or the trap's own clip
Integrated dishwasher
Built in under the worktop with a door panel.
- Feed the hoses through the cabinet hole before sliding the machine in
- Adjust the feet so the top fixing brackets meet the underside of the worktop
- Fix the door panel with the template from the box
- Check the door opens without catching the plinth
No valve, no standpipe, or no socket
A new installation, not a swap.
- Cutting a valve into the supply pipe is plumbing work on the water supply
- A new waste through an outside wall is drainage work
- A new socket is electrical installation work
- Get a plumber and, for the socket, an electrician — read the stop list
THE JOB
How to connect the machine
Set up: disconnect and drain the old machine
30 minFind your case in the cards above. Unplug the old machine and turn its valve lever across the pipe. Put a tray and towels in front of the filter flap at the bottom of the machine, open the flap, and let the water out through the small emergency hose or by slowly unscrewing the filter. Then undo the fill hose from the valve by hand and lift the drain hose out of the standpipe.
- Have a second tray ready; filters release water in bursts
- Lift the drain hose end into a bucket before taking it out of the standpipe
- Keep the old machine's power plug off the wet floor
Mistake to avoid: Undoing the fill hose with the valve still open. A washing machine valve is on mains pressure and the hose end sprays the wall and you.
Prepare the space and the valve
20 minThis is the prep from the cards above. Walk the old machine out on its feet. Clean the floor and the skirting. Check the valve: turn it on and off and watch for drips at its nut and spindle. Check the standpipe or the trap spigot is clear by pouring a jug of water down it. If the valve weeps or the standpipe is slow, fix that now, before the new machine blocks the space.
- A valve that weeps at the spindle sometimes stops with a small nip on its gland nut
- Look for old hose washers stuck in the valve's thread and pick them out
- Check the floor is level and solid where the feet will stand
Mistake to avoid: Pushing the new machine in front of a weeping valve. The drip then runs under the machine for months and rots the floor.
Remove the transit bolts
15 minOn a new washing machine, the drum is locked for transport with bolts through the back panel. Remove them with the spanner or tool in the box, as the machine's instructions show, and fit the plastic caps supplied into the holes. Keep the bolts taped to the back of the instructions in case the machine is ever moved again.
- Count the bolts against the instructions; models have three or four
- Fit every cap, or the holes let water and fingers in
- Dishwashers have no transit bolts, but check for packing inside the door
Mistake to avoid: Leaving one transit bolt in. On the first spin the drum hammers against it, the machine walks, and the warranty is gone.
Connect the fill hose
10 minCheck the rubber washer is in the valve end of the new fill hose. Screw that end onto the appliance valve by hand, firmly, and the other end onto the machine's inlet the same way. On a hot-and-cold machine, blue goes to cold and red to hot. Route the hose so it has no kinks and will not be crushed when the machine goes back.
- Hand tight is right; a spanner crushes the washer and splits the plastic nut
- Turn the valve on slowly and watch both ends for a minute
- Leave a loose loop so the machine can be pulled out for cleaning
Mistake to avoid: Tightening the fill hose with grips. The plastic nut cracks on the valve thread, and it fails later, under pressure, when no one is home.
Connect the drain hose
10 minHook the drain hose's U-shaped guide over the top of the standpipe and push the hose in only as far as the maker allows; the instructions we checked set a limit of 15 cm. Secure it so it cannot be thrown out when the pump runs. On a sink spigot, push the hose fully on and clip it, with a high loop up under the worktop first.
- Tie or clip the hose to the standpipe; pumping pressure can flick it out
- Never let the hose end sit in water in the standpipe
- If two machines share a standpipe, use a twin connector, not two hoses jammed together
Mistake to avoid: Pushing the drain hose deep into the standpipe. The machine then siphons, draining while it fills, and the cycle never ends.
Walk it in and level it
20 minWalk the machine back into the space, watching that neither hose is pinched or kinked behind it. Put the spirit level on top, across and front to back. Adjust the feet by unscrewing or screwing them, then tighten each foot's lock nut against the body while holding the foot still, as the maker describes. Rock the machine diagonally; it should not move.
- Level across and front to back; one direction is not enough
- On a soft vinyl floor, a firm board under the feet stops them sinking
- Leave a finger's gap at the sides so the machine does not touch the cabinets
Mistake to avoid: Skipping the lock nuts. The feet unwind on the first spin and the machine rocks again within a week.
Plug in and test
30 minPlug the machine into its socket. Run a short rinse or a quick cycle with no laundry. Watch the valve, both hose ends and the standpipe with a torch while it fills and while it pumps out. Pull the machine forward a little after the cycle and wipe a dry tissue along the hoses and the floor behind it.
- The first fill is the moment a fill hose washer leaks
- The first pump-out is when a drain hose jumps out of a standpipe
- Check the sink does not gurgle or fill when the machine pumps out
Mistake to avoid: Loading it with washing and walking away on the first run. A leak behind a machine is invisible until it reaches the kitchen floor.
Check again after a week
10 minAfter a few cycles, pull the machine forward and look again at the valve, the fill hose ends and the floor. Rock the machine; it should still be firm. Clean the filter flap after the first few washes on a new machine; packing grit collects there.
- A damp mark under the valve means a quarter turn on its compression nut
- If the machine has started to walk, re-level and lock the feet
- Turn the valve off when you go away for more than a few days
Mistake to avoid: Never looking behind the machine again. Fill hoses perish; check them each year and replace them every few years.
The mistakes that show
- Running a new washing machine with a transit bolt still in
- Pushing the drain hose too far into the standpipe so it siphons
- Overtightening plastic hose ends with tools
- Reusing the old machine's fill hose
- Not locking the levelling feet
Stop here and get a plumber
- There is no appliance valve and one has to be cut or teed into the supply pipe
- The waste must be extended, taken through a wall, or the standpipe is cracked in the wall
- There is no suitable socket and a new one is needed
- Making space means moving a gas cooker or its hose
| WHAT YOU SEE | WHY, AND THE FIX |
|---|---|
| Washing machine leaking from the back | Usually the fill hose washer at the valve or the machine end. Turn the valve off, unscrew by hand, check the washer is present and flat, and refit hand tight. |
| Machine drains while it fills | Siphoning: the drain hose is pushed too deep into the standpipe or the hose end sits below the water level. Pull it up to the maker's limit and use the U-shaped guide. |
| Water backing up out of the standpipe | The standpipe trap is blocked with lint, or two machines share it without a twin connector. Clear the trap and fit the right connector. |
| Sink fills with dirty water when the machine pumps out | The drain hose on the sink spigot has no high loop, or the sink trap is part blocked. Lift the hose into a loop under the worktop and clear the trap. |
| Machine shakes and walks on spin | Not level, lock nuts loose, or a transit bolt left in. Check the bolts, then re-level and lock all four feet. |
| Machine will not fill | The valve is off or part open, the fill hose is kinked, or the inlet filter is blocked. Open the valve fully, straighten the hose, and clean the small filter in the hose end as the instructions show. |
| Valve dripping at the lever | The spindle seal is worn. A nip on the gland nut sometimes stops it; otherwise the valve needs replacing with the water off. |
| Dishwasher drain gurgles and smells | The drain hose has no high loop, so dirty water sits in it. Raise it to the underside of the worktop before it drops to the spigot. |
WHAT YOU SAVE
What it costs to do it yourself
| Replacement appliance valve, if needed | £2–£9 |
|---|---|
| Fill hose, if not supplied | £6–£8 |
| Standpipe trap or twin connector, if needed | £12–£25 |
| Total, usually | £2–£25 |
| DIY total | £2–£25 |
Guide prices compiled by the Locufy team from published Irish and UK provider price lists and 2026/27 cost guides. Updated 2026.
Against a plumber's guide price for kitchen plumbing, a straight swap is nearly free: the new machine brings its own hoses, and the existing valve and waste do the rest.
RATHER NOT?
Kitchen plumbers near you, with prices shown
The ones who cover your area, nearest first, with one score from every review. No account needed to look.
Or post the job free and let them come to you.
Clean the machine's drain filter every month or two, and the small filter in the fill hose end once a year.
Inspect fill hoses each year for bulges and cracks and replace them every few years; turn the valve off when you go away.
A washing machine or dishwasher is electrical waste and cannot go in a bin. The retailer selling you the new one may take it back; otherwise take it to the electrical area at your council's household waste recycling centre or book the council's bulky waste collection. Find yours on the council website or the recycling pages for your nation.
Tape them to the instructions. If you ever move house, the drum needs them again.
Plumbing in a washing machine or dishwasher: questions people ask
Yes, if there is already an appliance valve, a standpipe or sink spigot, and a socket. Connect the fill hose by hand, put the drain hose into the standpipe no deeper than the maker allows, level the machine and test it.
Only as far as the machine's instructions say. One maker we checked sets 15 cm. Any deeper and the machine can siphon, draining while it fills.
Not if the valve, the waste spigot and the socket are already there. If a new valve has to be cut into the pipe, a new waste run, or a new socket added, that is plumbing and electrical work.
Whatever its instructions say. One we checked needs at least 0.2 bar and no more than 10 bar, which most mains-fed kitchens are well within.
No. It draws a high current for long periods, and an extension lead behind the machine can overheat out of sight. Use a wall socket.
Locufy's UK price guide puts kitchen plumbing at £100–£750 per job, typically £275 — the same three figures as the strip at the top of this page.
MORE GUIDES
More DIY guides
Sources — checked October 2026
- Bosch — washing machine installation and operating instructions: water pressure, hose lengths, levelling
- Flowflex — compression fittings technical data and installation instructions
- HSE — manual handling at work
- HSE — domestic gas safety: frequently asked questions
- Water Supply (Water Fittings) Regulations 1999, regulation 5
- Water Supply (Water Fittings) (Scotland) Byelaws Extension Order 2024
- Water Supply (Water Fittings) Regulations (Northern Ireland) 2009
- gov.uk — Approved Document P: electrical safety in dwellings (England)
- gov.wales — building regulations: electrics
- Gas Safety (Installation and Use) Regulations 1998, regulation 3
- Gas Safety (Installation and Use) Regulations (Northern Ireland) 2004, regulation 3
- gov.uk — recycling collections: find your council (England and Wales)
- mygov.scot — find your council's recycling centre (Scotland)
- nidirect — recycling and reusing (Northern Ireland)
- B&Q — price check: washing machine valves
- B&Q — price check: washing machine hoses
- B&Q — price check: standpipe traps