A toilet that constantly runs or leaks is not only annoying but also wastes a surprising amount of water. The most common culprits are the fill valve (which refills the tank) and the flapper (which seals the flush outlet). If both are worn or faulty, you may need to replace them. But how much does it cost in the UK to have this done by a plumber, and is it worth doing yourself? Let’s break it down.
Average Cost in the UK
In the UK, the average cost for a plumber to replace both a fill valve and flapper is typically between £80 and £150. This range includes:
- Labour costs: Most plumbers charge between £40 and £70 per hour. The job usually takes less than an hour.
- Call-out fee: Some plumbers include a minimum call-out charge (£50–£70), which covers the first hour.
- Parts: A new fill valve costs around £10–£20, and a replacement flapper costs about £5–£15. Some plumbers provide parts at trade prices, but others add a small markup.
Altogether, expect to pay around £100 on average if you hire a professional.
Factors That Affect the Price
- Location: Rates in London and the South East are usually higher, often closer to £120–£150.
- Emergency call-outs: Evening or weekend repairs can increase costs by 25–50%.
- Condition of your toilet: If the cistern is difficult to access (e.g. concealed or built-in), labour costs may increase.
- Additional repairs: Sometimes the flush valve, float arm, or cistern seals also need replacing, adding to the total cost.
DIY vs. Hiring a Plumber
Hiring a Plumber
- Pros: Professional finish, no risk of mistakes, usually comes with a short guarantee.
- Cons: Labour is the biggest part of the cost — often £80+ for a job you could do yourself.
DIY Replacement
- Pros: Saves £70–£120, most parts are universal, basic DIY skills are enough.
- Cons: May be tricky with older or concealed cisterns, risk of leaks if not installed correctly.
For most modern toilets, replacing the fill valve and flapper is a straightforward DIY project. If you’re comfortable with basic tools, you could complete the job in 30–45 minutes.
Recommended Replacement Parts (UK)
If you want to try the repair yourself, here are some highly rated options available in the UK:
Fluidmaster UK 400UK Fill Valve
- Height adjustable to fit most UK cisterns.
- Quiet fill design reduces noise.
- Trusted, widely used brand.
Siamp 99B Universal Flush Valve with Flapper
- Universal fit for UK cisterns.
- Durable design with easy installation.
- Includes adjustable overflow tube.
Macdee Dual Flush Cistern Repair Kit
- Includes both a fill valve and dual-flush valve.
- Good option for a complete cistern refresh.
- Designed for modern UK toilets.
Comparison Table
| Model | Best For | Key Features | Price |
|---|---|---|---|
| Fluidmaster 400UK | Standard replacement | Adjustable, quiet fill, universal fit | Check Price |
| Siamp 99B Flapper Valve | Universal flapper replacement | Durable, easy to fit, adjustable overflow | Check Price |
| Macdee Cistern Kit | Full repair | Fill valve + dual flush valve | Check Price |
FAQ
- Can I replace a fill valve and flapper myself?
Yes. Most UK toilets use universal replacement parts. It’s a DIY-friendly job if you’re comfortable turning off the water and using basic tools. - How long do these parts last?
Typically 5–7 years, though hard water can shorten their lifespan. - Is it better to replace both at the same time?
Yes. Since both parts wear at similar rates, replacing them together saves time and prevents repeat issues. - What if my toilet has a dual flush button?
You may need a compatible dual-flush valve kit rather than a traditional flapper.
Conclusion & Call to Action
In the UK, the cost to replace a toilet fill valve and flapper ranges from £80 to £150 if you hire a plumber. However, the parts themselves often cost less than £30 combined, making this one of the best DIY repairs for saving money. If you want professional peace of mind, call a plumber. But if you’re happy to get your hands a little wet, you can easily handle the job yourself and save a significant amount.
Looking for reliable replacements? Consider the Fluidmaster 400UK Fill Valve or the Siamp 99B Flapper Valve for a quick, effective repair. A small investment now can stop leaks, save water, and cut your utility bills.
