If you’ve ever heard your loo quietly refilling long after you’ve flushed it, you’ll know how irritating it can be. That constant trickle isn’t just background noise. It’s money literally going down the drain. I’ve visited plenty of homes needing toilet repairs in Brighton where the only sign of a problem was a slightly higher water bill and a faint hissing sound from the bathroom.
A running toilet might seem minor compared to a burst pipe or a boiler breakdown, but over weeks or months it can waste thousands of litres of water. Let’s break down what’s going on inside the cistern, what you can safely check yourself and when it’s time to get someone in.
Common Causes of a Running Toilet
Inside your cistern, there are only a handful of parts working together. When one of them isn’t quite right, water keeps flowing from the tank into the pan.
1. Worn or Misaligned Flapper
The flapper is the rubber seal at the bottom of the cistern. When you flush, it lifts to let water into the bowl, then drops back down to create a watertight seal.
Over time, that rubber can warp, harden or collect limescale, especially in hard water areas like parts of Sussex. If it doesn’t sit flush, water slowly leaks past it and the fill valve keeps topping up the tank.
2. Faulty Fill Valve
The fill valve controls the water coming into the cistern after each flush. If it’s set too high or starting to fail, it can keep running longer than it should.
I often find this in newer toilets with compact plastic valves. They’re efficient but not immune to wear. If you hear continuous hissing even when the tank looks full, the fill valve is usually to blame.
3. Overflow Tube Issues
If the water level in the cistern rises too high, it spills into the overflow tube and down into the pan. You might not see it unless you remove the lid, but if the water line is above the overflow opening, that’s your culprit.
Sometimes it’s just an adjustment issue. Other times the float mechanism isn’t cutting off the supply properly.
Simple Checks You Can Try Yourself
Before calling a plumber, there are a few straightforward checks most homeowners or tenants can safely do.
- Take the cistern lid off and check the water level. It should sit just below the overflow pipe.
- Add a few drops of food colouring into the tank and wait 15 minutes without flushing. If colour appears in the bowl, the flapper is leaking.
- Inspect the flapper for obvious warping or debris.
- Gently adjust the float if the water level is too high.
Many small issues can be solved with a replacement seal or a simple adjustment. Replacement parts are widely available and fairly inexpensive. Just make sure you turn off the water supply to the toilet before taking anything apart.
If you’re unsure what you’re looking at, don’t force anything. I’ve been to homes in Hove where a well meant DIY attempt turned a minor leak into a cracked cistern lid.
How Much Water Is Actually Being Wasted?
This is the bit that surprises most people. A running toilet can waste anywhere from 200 to 400 litres a day depending on the fault. Over a month, that adds up quickly.
If you’re on a water meter, you’ll see the impact on your bill. Even if you’re not, it’s still treated water that’s been cleaned, pumped and paid for in one way or another.
I once visited a flat in Worthing where the tenant thought the slight trickle was normal. Their landlord had no idea. After fixing the valve, the constant noise stopped and their quarterly bill dropped noticeably. It’s one of those problems that hides in plain sight.
When to Call a Professional Plumber
If replacing the flapper or adjusting the float doesn’t solve it, it’s time to get it looked at properly.
Call a plumber if:
- The toilet keeps running after you’ve replaced obvious parts.
- You notice cracks in the cistern.
- The water supply valve won’t shut off.
- You’re dealing with an older or concealed cistern built into the wall.
Concealed toilet systems, common in some renovated homes in Haywards Heath, can be more fiddly. Access panels are smaller and parts aren’t always universal. In those cases it’s usually quicker and safer to let someone experienced handle it.
Water Saving Tips and Preventative Maintenance
A bit of occasional attention can prevent most running toilet issues.
- Lift the cistern lid every few months and check for obvious wear.
- Listen for changes in sound after flushing.
- Deal with minor leaks straight away rather than waiting.
- Consider upgrading older toilets to dual flush systems if yours is outdated.
If your toilet is more than 15 years old and regularly playing up, replacing internal components or even the whole unit can be more efficient in the long run. Modern systems use far less water per flush.
A running toilet might seem like a small annoyance, but it’s one of the most common causes of hidden water waste I see in homes across Brighton, Hove, Haywards Heath and Worthing. Sorting it early saves water, money and hassle.
If you’ve checked the basics and it’s still running, or you’d rather have it properly sorted without the guesswork, you can book a professional plumbing service. The plumbing team at Brighton Plumbers are always happy to give straightforward advice and get things working as they should. Contact us today