By clicking a retailer link you consent to third-party cookies that track your onward journey. This enables W? to receive an affiliate commission if you make a purchase, which supports our mission to be the UK's consumer champion.
'Why does my bathroom tap only provide a trickle of hot water?' Expert advice from Which? Trusted Traders
Victoria has worked in lifestyle content for 20 years. In her three years at Which?, she's focused on helping consumers improve their homes, from remodeling the kitchen to buying the best laundry appliances.
With over a decade of experience at Which?, Tom covers everything from tech advice to money-saving tips, and highlights the best deals during major sales events.
'For the past few weeks, my bathroom tap has only provided a trickle of hot water. It's a mixer tap. I'm not sure whether it's worth replacing the tap or whether there could be an issue with the hot water tank pump. A boiler service engineer said it isn't related to the system boiler. The hot water from the kitchen sink works fine.'
Which? member
A loss of hot water from a single tap isn't always straightforward to diagnose. There are a couple of simple checks worth making first, but if the problem persists, you'll usually need a plumber to pinpoint the cause.
If a boiler engineer has already ruled out your boiler or hot water system, the fault is more likely to lie with the tap itself or the plumbing connected to it. A plumber can identify the problem and advise whether it can be repaired or if replacing the tap is the more cost-effective option.
We asked three plumbers endorsed as Which? Trusted Traders what they think is most likely to be causing the problem and how they would tackle it.
Use Which? Trusted Traders to find a reliable professional near you.
1. ‘In most cases, replacing the tap is the quickest and most cost-effective solution’
Elite Installations (South Yorkshire) Limited shared the following advice:
‘Based on what you’ve described, it’s very unlikely to be an issue with your boiler, pump or hot water tank – especially as your kitchen hot water is working normally.
‘When the problem is isolated to a single mixer tap, the most common cause is a build-up of limescale or debris within the tap’s cartridge or internal components, which can restrict the hot water flow.
‘We recommend running through the following:
- Check and clean the tap aerator (if accessible)
- Ensure the isolation valve on the hot feed is fully open
- If the issue persists, replace the tap or cartridge
‘In most cases, replacing the tap is the quickest and most cost-effective solution.
‘If you begin to notice reduced hot water flow at other outlets, it may be worth investigating the wider system – but from your description, this appears to be a tap-specific issue.’
How much do plumbers cost? We’ve surveyed Which? Trusted Traders to find out how much you can expect to pay for common plumbing jobs
2. 'As your other outlets are performing normally, the problem is likely specific to this fitting'
W4Plumber.com shared the following advice:
'If the issue is isolated to this tap, it's most likely a local fault rather than a problem with your plumbing system.
'Common causes include a worn or blocked cartridge, a kinked flexible hose, or a faulty non-return valve that's restricting the hot water supply. As your other outlets, such as the kitchen tap, are performing normally, this suggests the problem is specific to this fitting.
'A plumber should be able to diagnose the issue quickly and either repair the tap or advise whether repair or replacement is the more cost-effective option.'
3. ‘Most likely, this is a blocked or scaled mixer tap cartridge’
Sunrise Plumbing & Heating shared the following advice:
'Have you checked whether the mixer tap has an aerator? This is located at the end of the spout. Try unscrewing the aerator and cleaning the mesh, as this can sometimes restrict the water flow.
'Does the hot tap have a flexible tap connector and, if so, is it kinked? This could restrict the hot water flow, so gently straighten it to allow the water to flow freely.
'Most likely, this is a blocked or scaled mixer tap cartridge. Remove the cartridge, then clean or replace it.
'However, if the tap is older or a budget model, replacing the whole tap may be the easier option.'
Discover the best bathroom sinks, taps, toilets, baths and showers – we surveyed nearly 7,000 homeowners to find fixtures that stand up to daily use
Find a Which? Trusted Trader near you
Just like our well-known Best Buy logo, the Which? Trusted Trader logo is a mark of reputation and trust. It's awarded only to traders who successfully pass an assessment carried out by our trading standards professionals.
If you have an issue with your plumbing, visit Which? Trusted Traders or use the search tool below to find a specialist near you:
