Why it may not be safe to drink water from the upstairs tap…

Do you feel thirsty at night?

Be warned: it may not be safe to fill a glass of water from the upstairs tap.

This is because, depending on your home, your bathroom taps may be fed by a storage tank that is not considered safe to drink directly from by.

It may not even be wise to brush your teeth because of the same risks.

Many older homes get their water upstairs from storage tanks in the roof or attic.

Water from more modern versions of these tanks is now generally considered safe to drink, provided they are properly installed and maintained.

But the same does not necessarily apply to older models, according to the Drinking Water Inspectorate (DWI), the government regulator.

For example, some are too large, meaning the water in them can ‘remain’ for too long.

While such water is fine for washing your hands, it may mean that it is not technically ‘fresh’ enough to be safe to drink.

If water is allowed to sit for long periods of time, there may be a greater risk of contamination, either through the growth of bacteria or materials leaking into it from the container.

Although it is very unlikely that this will make you sick, the risk is not zero and such contamination can also affect the taste.

Other tanks are made of traditional metals that can rust over time, releasing bits of metal into the water – albeit in trace amounts.

Newer models must be built from plastic to prevent this.

Modern tanks also follow stricter standards, such as having filters to prevent pests and dust from entering and not placing them near heat sources that can cause the water to spoil more quickly.

So how can you check whether the tap water from your upstairs bathroom even comes from a tank or is connected to the mains?

The DWI says the easiest way to find out is to run the faucet fully and place your thumb under the spout.

If you can stop all the water this way, it’s probably being fed from a tank rather than from the wall socket.