How to fix a bath tap diverter? A step-by-step guide

An old bath tap is not just a relic of years gone by, but a proper workhorse that can keep going for decades… until something sticks. And nine times out of ten that “something” is the diverter. When you can’t have a peaceful shower anymore or the water insists on running from two places at once, it’s time to roll up your sleeves.

Below you’ll find a simple guide that will walk you through fixing the diverter in a bath tap – step by step and with no fuss. You’ll also see how the diverter in an old-style bath tap works and what the most common signs of its faults are.

How does the diverter in an old-style bath tap work?

The diverter in a classic bath tap is a mechanical component that redirects the water flow: either to the spout or to the shower head. It usually works with a spring and seals – the water pressure moves a spindle that changes the flow path. The mechanism is simple, but as in life, the simplest things fail most often.

The most common signs of a faulty bath tap diverter

When your diverter starts acting up, it usually lets you know in a very direct way. It stops responding to changes, sticks, or – the classic – after switching over, water still runs from both outlets. You might also find the pressure at the shower head suddenly drops – and it’s not necessarily the water mains’ fault.

Why doesn’t the diverter respond when you change mode?

A sticking diverter is often down to worn seals or limescale building up inside the tap. The water goes wherever it likes and you feel as if you’re switching modes only in your head. Sometimes the tired spring simply hasn’t the strength to lift the mechanism. That’s a sign it needs attention – ideally, a bit of DIY.

Water still dripping despite switching settings – what does it mean?

If you switch to the shower but water still drips from the spout (or vice versa), the culprit is an internal leak. The seals may be perished, deformed or just worn out. Limescale and grit don’t help either – they can stop the diverter working properly.

Pressure issues and the diverter in an older tap

In older models, the diverter often works only when the water pressure is high enough. If you notice it “only works sometimes”, it may be a mix of worn parts and pressure that’s too low. It’s also worth checking the tap’s filter – it may be clogged.

How to fix a bath tap diverter step by step?

Before you start, turn off the water. Always! Flooding the bathroom is the last thing you need. Once the stopcock is closed, get to work. To fix a bath tap diverter:

1. Remove the diverter knob – it’s usually held by a small screw under a cap.
2. Take out the diverter mechanism – it may be threaded or push-fit.
3. Check the condition of the seals and the spring – if they’re worn, buy new ones (to suit your tap model; it’s best to bring the old part to the shop so you can compare).
4. Clean everything thoroughly – limescale, grit and rusty deposits can jam the mechanism completely.
5. Replace worn parts and reassemble – make sure everything sits where it should.
6. Turn the water back on and test – if the diverter runs smoothly and is watertight, you can call it a job well done!

What to do if fixing the diverter doesn’t help?

Sometimes, unfortunately, the diverter is so worn that neither cleaning nor swapping the rubber bits makes any difference. Then the best solution is to replace the entire diverter cartridge or… the whole tap. Especially if it was already in poor nick. Modern bath taps are more efficient, but also often easier to service.

How to look after a bath tap to avoid diverter failures?

The best way to extend the life of the tap and the diverter is regular descaling – both outside and inside. Every so often, it’s worth unscrewing the ends, rinsing the filter and checking the seals. And it won’t hurt to “click” the diverter now and then, even if you’re not using the shower – it helps prevent it seizing up.

Fixing a bath tap diverter doesn’t have to be expensive or complicated. All you need is a bit of patience, basic tools and a can-do attitude. And the satisfaction of a bath where the water goes exactly where it should? Priceless.