There are a few easy clues. First, if your toilet is older and doesn’t have any dual-flush buttons or modern stickers, it’s likely using more water by design. Older models can use double or triple the water of newer low-flush toilets.
Watch how long the cistern takes to refill. If it’s constantly running or takes a very long time, something may be off with the mechanism. You can also look inside the tank (carefully lifting the lid) and check the water level. If it’s set very high, each flush sends more water than necessary.
A classic test is the food colouring trick. Put a few drops of food colour or coloured liquid in the cistern and wait without flushing. If colour appears in the bowl after some time, there’s a leak between tank and bowl, so water is being wasted even when you’re not flushing.
If you suspect overuse, a plumber or professional can adjust the float, replace the fill valve, or suggest an upgrade to a more efficient system.
