How to replace bath taps

Video by Plumberparts. This walk-through is based on the video “HOW TO FIT A BATH TAP - Plumbing Tips” from Plumberparts, who cover everything from isolating the supply through to fitting the new taps and checking for leaks. It is worth watching before you start — the section on dealing with the back nut in a tight space is particularly handy.

1. Turn off the water and drain the pipes

Before touching anything, track down the isolation valves on the hot and cold supply pipes under the bath panel. Most UK baths have inline isolators — a flathead screwdriver slot on the valve body. Turn each one a quarter-turn so the slot runs across the pipe rather than along it. That means it is shut.

If there are no isolation valves under the bath, you will need to turn off the main stopcock — usually under the kitchen sink or where the rising main enters the house. Once the water is off, open both bath taps fully to drain any water still sitting in the pipes. Keep a towel and a small bowl close by; there will always be a bit of residual water when you disconnect the flexi hoses.

2. Remove the bath panel and access the tap connections

Most standard UK baths have a clip-on or screw-fixed side panel. Pop it off carefully — a flat pry bar wrapped in a cloth works well to avoid scratching the panel. Once it is out of the way you will be able to see the underside of the bath and the tap tails dropping down through the tap holes.

Have a look at what you are dealing with. Older taps often have separate hot and cold pillar taps with a back nut on each tail. More modern mixer taps come through a single central hole with two flexible supply hoses attached. Either way, the job is the same: disconnect the supply, undo the back nut, and lift the tap out from above. That said, older properties sometimes have very corroded connections, so soak any stubborn nuts with penetrating oil for 20 minutes before you attempt them.

3. Disconnect the supply hoses and remove the old taps

Use an adjustable spanner to loosen the compression fittings or push-fit connectors on the supply hoses below the bath. Hold the flexi hose with one hand so it does not spin and stress the pipe above. Once loose, unscrew fully and tuck the hose aside. Do the same on both hot and cold.

Now reach in with a basin wrench — that long-handled tool with the swivelling jaw — and turn the back nut anti-clockwise. It is a slow job in a tight space, but a basin wrench makes it possible without bruised knuckles. Once the nut is off, the tap tail lifts straight out through the hole from above. Remove any old sealing putty or silicone from around the tap hole and clean the bath surface back to bare acrylic or enamel before fitting the new tap.

4. Prepare and fit the new taps

Most replacement taps come with a rubber gasket or a flat fibre washer that sits between the tap base and the bath surface. Check which one is supplied — if neither is included, pick up a matching tap hole gasket from any plumbers’ merchant. Drop the tap tail down through the hole from above, making sure the tap sits square and faces the right direction.

From below, slide on any spacer plate, then the back nut, and hand-tighten it first. Once it is finger-tight, use the basin wrench to snug it up. You do not need to overtighten — firm enough that the tap cannot rotate when you turn it on, but no more. Crushing the gasket will not improve the seal; it will just damage it.

5. Reconnect the water supply

Wrap two or three turns of PTFE tape clockwise around the threaded tail of each tap before connecting the supply hose. This is the first thing most people skip and the most common reason a newly fitted tap drips from below. Use new flexi hoses if the old ones are more than a few years old — they are cheap and it is not worth reusing a hose that might fail behind the panel.

Connect the hot supply to the hot tap and cold to cold — obvious, but worth double-checking before you tighten up. Hand-tighten first, then nip up with a spanner — again, no need to go hard. Open the isolation valves slowly and let the system pressurise. Watch the connections for a minute before moving on.

6. Check for leaks and refit the panel

With the water back on, turn each tap fully on and off a couple of times to check the action is smooth and nothing is dripping at the connections below. Run the hot tap until you are sure it is coming through properly. If a joint weeps slightly, do not immediately tighten harder — try a small additional wrap of PTFE tape on the thread first.

Once you are happy everything is dry, refit the bath panel and give the tap bases a thin bead of sanitary silicone where they meet the bath surface if there is any gap. Clear silicone, not white — it stays tidy far longer. Stand back, admire the new taps, and remind yourself it took less time than waiting for a plumber.

When to call a handyman

Call Richard if the supply pipes under the bath are copper soldered joints rather than compression or push-fit fittings, if the tap holes in the bath are a non-standard size that needs adapting, or if the old taps simply will not budge despite penetrating oil and a good effort. Bath access can also be tight in older terraced houses and semis around Sandwich — sometimes an extra pair of hands makes the difference between a clean job and a frustrating afternoon.