Why Is My Water Bill So High? (Hidden Leaks)

If your water bill suddenly jumped with no change in how you use water, the most common cause in Singapore is a hidden leak, usually a running toilet cistern or a slow leak in a concealed pipe. A single leaking toilet flapper can waste hundreds of litres a day without any visible dripping, which quietly pushes your monthly bill up. The fastest way to confirm it is the meter test: turn off every tap and appliance, then check if your water meter is still moving.

Water in Singapore is billed by PUB based on how much passes through your meter, so any water lost after the meter but before your taps is water you still pay for. This guide walks through why bills spike, how to find the leak yourself, and when to bring in a plumber to trace and repair it properly.

What counts as a high water bill in Singapore?

There is no single normal figure, since it depends on household size, but a useful check is your own history. Compare the current bill against the same month last year and the past few months, which you can see on your SP utilities bill or the SP app. A jump of 30 percent or more with no lifestyle change is a strong signal that something is leaking.

Remember your SP bill bundles water, electricity and gas together, plus the waterborne fee and water conservation tax that scale with usage. So a leak does not just raise the water charge, it also raises the taxes tied to volume, which is why even a small constant leak adds up over a month.

How do I run the water meter test?

The meter test is the single most reliable way to confirm a hidden leak, and it takes about ten minutes. Your meter is usually at the riser or in a recess outside the flat entrance for HDB units, or in the meter compartment for landed homes and condos.

• Turn off every tap, the washing machine, dishwasher and water heater, and make sure no toilet is refilling.
• Look at the meter and note the reading, including the small red dial or the last digits that move for tiny flows.
• Wait 15 to 30 minutes without using any water at all.
• Check the meter again. If any digit or the flow indicator has moved, water is escaping somewhere between the meter and your taps.

Where are the hidden leaks usually found?

In most Singapore homes the culprit is the toilet, because a worn flapper or faulty fill valve lets water trickle from the cistern into the bowl silently. A quick test is to add a few drops of food colouring into the cistern, wait 15 minutes without flushing, and see if colour appears in the bowl. If it does, the flush valve seal is leaking.

• Toilet cistern: worn flapper, faulty fill valve, or a stuck float.
• Concealed wall and floor pipes: slow leaks behind tiles, often showing as damp patches, bubbling paint, or hollow tiles.
• Water heater and connections: dripping at joints or the tank itself.
• Kitchen and basin traps: leaks under the sink that drip into the cabinet.
• Bib taps and hose connections at the service yard or balcony.

Can a hidden leak damage more than my bill?

Yes. A slow concealed leak can soak into screed and walls, causing damp stains, peeling paint, mould, and swollen skirting, and in flats it can seep down to the unit below. Inter-floor leaks between HDB or condo units can turn into disputes and shared repair costs, so early detection matters.

If you notice persistent damp, a musty smell, or tiles that sound hollow when tapped, treat it as urgent. The longer a concealed pipe leaks, the more waterproofing and finishing you eventually have to redo.

How do I get the leak found and repaired?

Simple fixes like swapping a toilet flapper or fill valve, or tightening a tap connection, are within reach of a handy homeowner. But when the meter test confirms a leak you cannot see, you need a plumber who can trace concealed pipes without tearing up the whole floor, using pressure testing and leak detection tools to pinpoint the source first.

For concealed pipe work it is worth using a licensed plumber, since work on the potable supply should meet PUB requirements and be done by a competent person. If you would rather not chase it yourself, our team handles water leak detection and repair across Singapore homes, from cistern swaps to tracing and fixing concealed pipe leaks before they damage your finishes.

Frequently asked questions

Can a leaking toilet really raise my bill that much? Yes. A continuously running cistern can waste hundreds of litres a day, which over a month is enough to noticeably raise your water charge plus the volume-based taxes on your SP bill.

Does PUB give any allowance for a bill spike caused by a leak? PUB may consider a review or adjustment in certain leak cases, but this is not automatic and depends on the circumstances, so contact PUB directly and keep evidence of the repair. Do not assume the extra cost will be waived.

How can I tell if the leak is before or after my meter? Run the meter test with everything off. If the meter moves, the leak is on your side, after the meter, and is your responsibility. Leaks on the supply side before the meter are handled differently, so report those to PUB.

Should I fix a concealed pipe leak myself? For a visible tap or a toilet part, yes. For concealed pipes behind walls or floors, use a licensed plumber, since it needs proper leak tracing and often waterproofing to restore the finish correctly.