That constant trickle or hiss from your toilet isn’t just annoying. A running toilet can waste a lot of water every day, and you pay for every drop on your utility bill. The good news: the cause is usually a small, fixable part inside the cistern.
First, confirm the leak
Try this simple test:
- Remove the cistern lid, if your toilet has an exposed tank.
- Add a few drops of food colouring to the water in the cistern.
- Don’t flush. Wait 15 to 20 minutes.
- If colour appears in the toilet bowl, water is leaking through from the cistern.
The 5 most common causes
1. Worn flush valve seal
The rubber seal at the bottom of the cistern hardens and warps over time. Water slowly seeps past it into the bowl, and the cistern keeps refilling to replace it. This is the most common cause.
2. Faulty inlet (fill) valve
This valve lets water into the cistern and shuts off when it’s full. If it’s worn or clogged with debris, it never shuts off fully, and water keeps flowing.
3. Water level set too high
If the float is set too high, water rises above the overflow pipe and drains straight into the bowl, nonstop.
4. Stuck flush button
Many Singapore homes have push-button or dual-flush cisterns. If the button mechanism sticks or doesn’t spring back, the valve stays slightly open.
5. Mineral build-up
Scale and grit from the water supply can stop parts from sealing or moving properly.
What you can safely check yourself
- Press the flush button a few times to see if it’s sticking
- Look at the water level: is it above the overflow pipe?
- Close the stop valve (the small tap on the pipe beside the toilet) to stop the water while you wait for a repair
If the problem is a worn seal or a faulty valve, the part usually needs replacing. Parts vary by cistern brand and model, and concealed cisterns built into the wall need careful access through the panel.
When to call a professional
- The toilet still runs after you’ve checked the button and water level
- Water is leaking onto the floor around the toilet
- You have a concealed cistern behind the wall
- You’d rather have it fixed properly in one visit
Fast, reliable toilet repairs
Handyman Service Hero fixes running toilets, leaking cisterns, faulty flush buttons and inlet valves in HDB, condo and landed homes across Singapore. Call or WhatsApp us with a photo or short video of your toilet, and we’ll give you a clear quote before we start.
