Got a PUB smart water meter high-usage alert? What to check

What a PUB smart water meter high usage alert tells you

PUB is fitting smart water meters in phases. Where one is fitted, PUB's MySmartWaterMeter web application shows the previous day's use by the hour and can send a leak or high-usage alert. PUB describes MySmartWaterMeter as a web-based application, so you can open it on any device, and PUB's smart water meter page explains what it shows.

According to PUB, you can view your use at hourly intervals for the past one day, daily intervals for the past 7 days and monthly intervals for the past 12 months. The data is refreshed once a day, when the previous day's use becomes available by the hour. Notifications on suspected leaks and abnormal or high consumption go to the registered mobile number, so make sure that number belongs to someone who will act on an alert.

An alert tells you that use looked high or unusual, not where the water went. A day of heavy laundry can look like a slow leak in the daily total, so the hourly pattern matters more than the alert.

Read the hourly figures before you worry

Open the hourly view and go through it hour by hour. Look first at the hours when nobody in your home runs water, such as overnight. A steady flow through every hour, including those, points to a leak. One spike that matches a laundry day, long showers or guests staying over points to normal use.

PUB says the dashboard figures are intended to give an estimate of use and are not used for billing. During data updates, the dashboard may show a blank or estimated reading for a period. If you see a gap, check again after the next refresh before you draw any conclusion. PUB also says you can set water usage targets for your household.

If a bill also looks too high, read the guide to a high water bill as well. If the spike happened while the home was empty, go through the checks before an overseas trip.

Test for a leak with the meter

To check for a water leak in an HDB flat or any other home, start with the meter itself. PUB's Tips on Finding Leaks says to turn off all taps and appliances that use water, then watch the water meter for at least 10 minutes. If the dial moves, there is a leak.

PUB's guide also lists these signs of a leak:

• a higher than usual bill
• a running or dripping sound at night when no appliances are in use
• mould, discolouration or peeling paint
• foul odours

For the toilet, PUB suggests putting a few drops of food colouring or a leak detection tablet in the cistern tank. If colour appears in the bowl, the cistern is leaking.

If the meter test shows a leak but you cannot see where it is, the leak has to be found before it can be fixed. See the guide to leak detection cost; what it costs depends on the job.

The usual suspect: the toilet cistern

Cistern leaks are easy to miss. In PUB's earlier trials at Punggol and Yuhua, about 10% of the 800 households had leaks, mostly at the water cisterns. PUB notes that such leaks often go unnoticed until a higher than usual bill arrives.

The amounts add up. PUB's Tips on Finding Leaks says a leaking flushing cistern can lose more than 10 litres of water per hour, and a dripping tap up to 2 litres per hour. A slow leak like this runs through every hour, including overnight, so it tends to show up in the hourly view as use that never drops to zero. That pattern is the main reason to act on a smart water meter leak alert even when you cannot hear anything.

Listen near the cistern when nobody has flushed. If it refills on its own, or a thin trickle runs down the back of the bowl, use the colour test above to check for a leak. For causes and fixes, see what to do when your toilet keeps running.

Who fixes what

PUB's Plumbing Works page says regulated water supply and sanitary plumbing works must be carried out by a PUB Licensed Plumber, except simple plumbing works that handymen can do, such as replacing or removing a tap or mixer, or replacing a cistern's flushing mechanism or the flexible hose after the ball valve. Most other water supply pipes are not on that list, so a leak in them is work for a PUB Licensed Plumber. The list does include replacing or removing a flexible hose connected to a tap, or any pipe between a stop valve and an instantaneous water heater.

Before anyone comes, note the meter readings and the hours of the alert. Keep a screenshot of the hourly view and the results of the meter test and the colour test, so whoever comes can start where the evidence points.

To compare plumbing companies for the fix, see water leak repair. What a repair costs depends on the job.

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