A trickling leak down the back of the bowl doesn’t cost much. 
You might want to sit down for this: a leaky loo can add up to £584* a year to your water bill if you have a meter. Even if it’s less than this, it could still double your bill. By losing up to 400 litres a day, a continuous leak can really add up.

A dribble inside the toilet doesn’t waste much water. 
A leaky loo can waste up to 400 litres a day. That’s the same as filling FIVE bath tubs every single day. And every litre’s tap-quality water – just going straight down the pan.

I don’t need to check my loos once a month.
Hidden leaks down the back of the bowl can be silent, almost invisible – and start at any time. Because they can quickly lose such a huge amount of water and add a lot to your bill, we recommend a monthly check. It’s the best way to avoid wasting money and water.

It’s only toilet water. It’s not precious like drinking water.
Every litre we supply to your home is tap-quality water, locally sourced from underground chalk aquifers and carefully treated to be safe to drink. Which means the water in your loo is exactly the same as the water from your taps – and having a leaky loo is like leaving a tap dripping constantly. Every litre you stop leaking helps protect our local chalk streams, including the Cam.

Leaky loos aren’t common. I don’t need to check mine.
Across the UK, 1 in 8 homes has a hidden leaky loo. Think how many there could be on your street. In fact, during our Yes We Cam campaign in 2024, 25% of Cambridgeshire residents who checked their loos found leaks they didn’t know about.

If my loo was leaking, I’d definitely notice.
A leaky loo, with a continuous trickle down the back of the bowl, is one of the hardest leaks to spot. It can be silent and hidden, and there aren’t any puddles on the floor to give it away. But it can lose a huge amount of water – and cost a lot of money in higher bills.

Old-style toilets are the worst for hidden leaks.
Actually, modern dual flush toilets are the biggest culprits of trickling leaks down the back of the bowl. This is because the flush mechanism tends to get debris, like limescale, trapped inside it, preventing the flush unit from fully sealing and allowing water to dribble into the bowl.

You need a plumber to tell you if you’ve got a hidden leak.
It’s really easy to check your loos for a leak down the back of the bowl. All you need is a sheet of toilet paper. Find out how to check your loos here.

I don’t need to bother fixing a leak that doesn’t make any mess.
Although there’s no puddles, a leaky loo can waste a huge amount of money and water – up to 400 litres a day, costing up to £584* a year. That’s one reason why 75% of Cambridge Water customers say they’d get into the habit of checking their loos at the start of each month**.

Leaky loos are hard to fix.
Good news – leaky loos can be very easy to fix and people often fix their own. The first thing to try is a simple DIY trick. We’ve got a step-by-step guide here. If you do call a plumber, it’s usually a straightforward job and 70% of leaky loos are fixed on the first visit†. The average cost is around £150‡ – and remember, you start saving money right away.