Is It Safe to Drink Hot Tap Water?
Design | 12-06-25
It’s a fair question – and one more Australians are starting to ask.
In most homes, hot tap water is not treated or monitored as drinking water. Unlike cold tap water, which is filtered, disinfected and closely regulated, hot water often comes from a storage system (i.e. your hot water system) that wasn’t designed with drinking in mind.
So, can you drink hot tap water? And if not, why not?
In this article, we’ll take a closer look at what happens to water when it’s heated inside your home, the health risks that may come with it, and the safer alternatives experts recommend.
We’ll cover:
- Can you drink hot tap water?
- Why hot tap water may not be safe to drink
- Is warm tap water safe to drink?
- What to do instead
Can you drink hot tap water?
No – hot tap water is not recommended for drinking in Australia.
According to NSW Health, hot water from your tap can dissolve metals from pipes and provide a breeding ground for bacteria if stored at the wrong temperature. It may also bypass household filtration systems entirely.
The Australian Drinking Water Guidelines are clear: drinking water should be free from harmful levels of chemicals and microorganisms. The guidelines also note that water quality can be affected by temperature and plumbing materials – both of which come into play once water is heated and stored inside your home.
That’s why cold tap water is always recommended for drinking and food preparation (even if you plan to boil it).
Okay, so what makes hot tap water different? And why does it matter?
Why you shouldn’t drink hot tap water
Is it unsafe to drink hot tap water? Yes. But that’s not because of the water itself. It’s what can happen to it once it’s heated and stored inside your home. Here are the three main reasons it’s not recommended for drinking.
1. Metal contamination from pipes
Hot water is more likely than cold to dissolve metals like lead, copper and zinc from your plumbing, especially in older homes or those with outdated fittings. The hotter the water, the more it can corrode or leach from your pipes.
According to the Victorian Department of Health, small amounts of metals like lead can enter hot tap water through older brass fittings, soldered joints and storage tanks. Even low levels of exposure may pose health risks over time, particularly for children and pregnant women.
2. Bacterial growth in hot water systems
Hot water heaters can provide ideal conditions for certain types of bacteria, including Legionella, which causes Legionnaires’ disease. That’s because some systems store water at temperatures too low to kill bacteria but warm enough to encourage growth.
Poor maintenance or fluctuating temperatures in hot water systems can allow bacteria to multiply unnoticed. That risk increases if water sits stagnant in a tank or pipe for too long.
3. Hot water may bypass filtration
In many Australian homes, filtration systems are only installed on the cold water line. That means hot tap water often bypasses any form of treatment.
So even if your home has a high-quality water filter, it's possible that only your cold water is being filtered. Any metals, bacteria or sediment present in the hot line will go straight into your cup if you drink from the hot tap.
Together, these risks are why public health experts consistently recommend using only cold tap water for drinking and food preparation.
It's pretty clear: don't drink hot tap water. But is warm tap water any different?
Is warm tap water safe to drink?
It might seem like a safer option, but warm tap water has the same concerns as hot tap water. That’s because it usually comes from the same source: your home’s hot water system.
Whether it’s straight from the hot tap or a mix of hot and cold, that warm water has still passed through plumbing and storage conditions that aren’t designed for drinking. It may contain dissolved metals, bacteria, or other contaminants that cold water hasn’t picked up (especially if your filtration system is only connected to the cold supply). Cold tap water is the safest option for drinking and cooking.
So, if you need warm water—for tea, cooking, or baby formula—it’s best to start with cold water, then heat it in a kettle or on the stove. That way, you’re getting the benefit of clean, regulated drinking water with none of the risks that can come from your hot water line.
How hot water systems work (and what that means for drinking water)
Most people don’t think about what happens to their water once it enters their home. But your plumbing setup matters more than you might expect.
In Australia, hot water usually comes from one of two types of systems:
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Storage systems (electric, solar, or gas): These heat and hold water in a tank until you need it.
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Continuous flow systems (also called instantaneous): These heat water on demand, without storage.
Both systems are designed for washing and bathing – not for drinking. Storage systems can hold water for hours, allowing bacteria to multiply, especially if the temperature drops into the "danger zone" (20-50°C).
Continuous systems don’t store water, but they still heat it through pipes that may contain metals or biofilm buildup.
In either case, the water is rarely filtered, and often travels through plumbing not designed for consumption.
By contrast, filtered boiling water systems—like a Zip HydroTap—heat water at the point of use, then deliver it instantly through a tap designed for drinking. What’s that? You can drink from the hot tap if you install a HydroTap? That’s right. Because there’s no holding tank and no long stretches of pipe to corrode. Let’s look closer at some safe alternatives.
What to do instead
If you haven’t installed a HydroTap and you can’t drink hot tap water, what should you use instead?
Health authorities across Australia agree: cold tap water is the best and safest starting point for anything you plan to drink, cook with, or use in baby formula. Even if you're going to boil it, always start with cold water. Here’s what they recommend.
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Use cold tap water for all drinking and cooking. This includes filling kettles, cooking pasta, soaking rice, or making up bottles. Cold water comes directly from the mains, and in most homes, it’s filtered or treated to meet drinking water standards.
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Heat cold water safely. If you need hot or warm water—for tea, coffee, or food prep—boil it using a kettle or on the stove. This ensures you're starting with water that’s safe and free from added contaminants.
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Be especially careful for babies and vulnerable groups. If you're preparing baby formula, always use boiled, cold tap water that has cooled to a safe temperature. The same goes for older adults or anyone with a weakened immune system.
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Check your pipes if your water tastes or smells odd. Sometimes the issue isn't your water supply – it’s your plumbing. It might be worth getting your pipes checked and considering filtration if you're noticing metallic, musty or chemical notes.
Cold tap water gives you the cleanest baseline. From there, it’s about how you heat it, store it, or deliver it – and that’s where Zip Water comes in.
A safer and faster way to enjoy hot water at home
You shouldn’t have to choose between safety and convenience. And with a Zip HydroTap, you don’t have to.
A HydroTap gives you instant filtered boiling, chilled or even sparkling water right from your tap – delivering the performance you need, without the risks that come with traditional hot water systems.
Here’s how a HydroTap is different.
Filtered at the point of use
Zip Water’s MicroPurity filtration filters down to 0.2 microns. That’s fine enough to reduce eight of the most harmful contaminants you can't see, smell or taste in your water, including microplastics, asbestos and lead – along with 99.4% removal of PFAS*. Remove contaminants before they reach your glass.
No tanks, no guesswork
Unlike household hot water systems, Zip Water systems don’t store water for hours. Instead, they heat and filter water on demand, meaning no stagnation, no fluctuating temperatures, and no plumbing surprises.
Designed for real life
Whether you're making a quick cup of tea, topping up a bottle, or prepping a meal, Zip gives you water that's ready, reliable, and refreshing (without clutter or compromise).
Built for taste and peace of mind
Clean, great-tasting water encourages better hydration. And when it comes to hot water, a HydroTap gives you the confidence of knowing exactly where it comes from – and what’s been taken out.
Explore the Zip HydroTap range or learn more about boosting your family’s health with filtered water. It’s a smarter, more convenient way to stay hydrated, cook confidently, and enjoy better water every day. Because when it comes to your health and your home, you shouldn’t have to compromise.
Are you interested in what type of water you have in your home and how it can affect you? Learn more about hard water vs soft water across Australia.
* Zip MicroPurity filters sizes 1 and 1.5 (93701 and 93702) are certified to NSF/ANSI Standard 53 to reduce 99.4% of Total PFAS (average reduction).
