Is It Safe to Drink Hot Water from Tap

Hello,

I have water heater installed at my apartment. I drink normal tap water, but in winter I often drink hot tap water.

I was just wondering whether the water heater mixes some chemical while heating the water.Is it safe to drink hot tap water?

Thanks.

Comments

  • Could be a myth, but I don't drink water from the hot water tap because I have been told hot water pipes often contains rust.

    • +2

      wouldn't cold water taps also contain rust?

  • +5

    Its perfectly fine. Hot water might look a bit cloudy (white) as it has air bubble in it from boiling if the heater is far away and too hot. Its extremely rare that rust hurts you (you would know from eating red meat etc), so just let it run for a few secs before you use your glass. If it has an odd taste then it might be time to clean/upgrade the hot water system.

    • +4

      A couple of misconceptions there: blood is not rust or vv. Although both contain iron, they are in different forms. Blood contains hemoglobin, which binds iron, which binds oxygen. In fact the red juice in red meat is not blood either, but a mixture of water and myoglobin.

      But it's correct that a bit of iron oxide in water is harmless, it's naturally occurring, it's not very soluble in the water so you wouldn't get enough to cause effects. Most domestic hot water boilers are glass lined these days. So no worse than drinking water from a kettle.

      If you want hot water to drink quickly, an efficient method is to heat a mug of it in the microwave oven.

      • +2

        If you want hot water to drink quickly, an efficient method is to heat a mug of it in the microwave oven.

        Be super careful doing this.

        https://en.wikipedia.org/wiki/Superheating

        • I like the furious bubbling when I lower the tea cage into the teapot, helps stir up the tea. :)

  • +3

    NSW Health:

    “Use water taken straight from the cold water tap for drinking and cooking. Hot water systems and pipes generally contain more dissolved minerals and metals, due to the heating process.”

    Also if you have an old house:

    "Back in the day, hot-water pipes used to be made from copper or lead, with lead a massive problem as it leached into the water."

    • +2

      New houses use copper…
      Old houses used Galvanised steel, maybe even older houses used Lead, but they'd be pre-war builds.

      • True, just pointing out for OP.

      • +5

        New houses use copper…

        All plastic these days.

        • Was going to say the same thing. No copper in sight when my current house was built almost 10 years ago. All plastic with some brass looking crimp type connectors.

        • @woteva: Why are they using plastic now? How is plastic any better than copper for heat transfer/durability? Plus doesn't plastic melt from boiling hot water? I once poured boiling hot water in a plastic cup to make coffee and tea (so it's a mixture of coffee and tea together in one cup) and it melted away…..

        • @Zachary:
          Well, not plastic exactly, it would be some type of Polly and our gas water heater is regulated to 60 degrees.

          Some machines I work on have a clear plastic type tube for oil sight level and oil temperature usually sits around 90 degrees and can rise up to 120 on a hot day.

        • @Zachary:

          Why are they using plastic now?

          Drainage stuff has been PVC for yonks, when was the last time you saw a metal S-bend under a sink? (Ok, one at my house does.)

          The rest is PEX, a type of HDPE (similar to chopping boards).

          Handles heat just fine, probably what plastic kettles are made from.

          As to why, lots of reasons. For hot water it's better than copper as it's an insulator, you won't lose as much heat as a copper pipe does. Cheaper, faster to install, no scrap value so junkies don't tear up your house, less prone to freezing, less water hammer noise etc.

        • @D C: > when was the last time you saw a metal S-bend under a sink? Recently when the bathroom was getting renovated and the pipes were all metal……and I saw the builder fix up the pipes with new copper pipes, the old pipes looked corroded and oxidized with all that green gunk and dulled shine… instead of plastic ones like you said should happen…..

          As to why, lots of reasons. For hot water it's better than copper as it's an insulator, you won't lose as much heat as a copper pipe does. Cheaper, faster to install, no scrap value so junkies don't tear up your house, less prone to freezing, less water hammer noise etc.

          Oh, insulator, didn't think of that….I was thinking that the copper pipes would still keep the water warm since the pipes are already pre-heated thanks to previous water run when you want to re-run the taps again, for a 2nd warm shower for exmaple….so you don't get cold water when you turn on the hot stream in….

          lol junkies tearing up your house….hahahahaha……freezing doesn't really happen here since we like never hit less than 0 degrees celsius, ok fair enough on the noise the pipes make when water runs through them. What about durability? Isn't metal more durable and thus lasts longer than plastic?

        • @Zachary:

          instead of plastic ones like you said should happen…..

          The pipes in the walls are plastic these days, from the wall to the taps are braided metal flexible hoses (like these: https://www.bunnings.com.au/kinetic-450mm-flexible-water-con…).

          If your plumber used copper pipe it's either because he's old or more likely couldn't be arsed fitting a tap etc for the hoses. Even then it would have been compression fittings, not soldered. If done from scratch it would be all plastic & hoses.

          If the s-bend needed replacing plastic would have been used.

          Isn't metal more durable and thus lasts longer than plastic?

          Maybe, maybe not. I'd expect plastic to last longer than copper as it won't corrode. Plastics are damaged by UV light, not likely to happen when it's in your wall. Ideally you'd get over 50-odd years out of each. Generally speaking either should outlast you.

        • @D C: Yeah he was pretty old…..I guess….might explain it…thanks…..

        • @Zachary:

          Lol, you think they make water pipes out of rolled up icecream containers or something?

          There's plastic, and there's " plastic "

  • +1

    The problem with hot water I believe is tank hot water where thermo-tolerant bacteria can happily grow. Most importantly, old, unsealed tank hot water systems can crawl in!

    If you have instantaneous Hot water then your problems should be minimal, but if you have tank hot water, it could be a problem.

    • This is correct, but obviously only for storage systems, but most good hot water systems will heat the water will heat the water to 75 once a day which will kill all bacteria.

  • +1

    You should buy a kettle and wifi switch with a timer. Then you can wake up to some nice warm water.

    • Lots of kettles (my kettles anyway) won't keep the switch on unless there's power going to it :(

  • -3

    Pls enjoy your salt water.

    • Where do you think the vast majority of the rain comes from?
      Hot tip, it's not magically appearing in the sky…

      • -1

        cloud seeding.

  • +2

    Depends on how your water is heated. I wouldn't drink it if it came from a hot water tank, I would if it was instantaneous heater. Used to have a hot water tank that had the nastiest looking water before replacing it (rusty tank).

  • +2

    after decommissioning a few hot water heaters and seen what sludge sits at the bottom I pass on this one.

    Instant ones are much safer. Forget about bottled water, not worth the money. Get a membrane from whatever Bay and enjoy pure water, costs little. Heat clean water in the microwave.

  • +1

    We used to have a hot water tank at home and I've been told from a young age not to drink hot water from the tap. And I've just avoided it since.

    Logically thinking, the heat from the hot water sitting in a tank (could be for many hours or even days) would "wash off" and dissolve a lot of the contaminants that sit in the tank. Like flushing/washing something with hot water instead doing it with cold water. I'd imagine that the hot water does a better job of "cleaning" and hence will end up having many more "floaties".

    If I want hot water, it takes 3 minutes to boil cold water in the kettle.

  • it all depends how hot the water is

  • +2

    Depends on the hot water system. If it is a stored hot water system, then probably no. But if it is instant, then the water is almost new when it comes out the tap.

  • It's fine as long as you let it cool before you drink it to avoid burns

  • IF you want safe hot water, first have the water be distilled/filtered by one of those purifiers thingy and then pour that filtered water in a kettle or pan and heat it up and pour that heated water back in a glass cup for drinking pleasure.

  • If running a regular storage Hot Water System, then this is why its not recommended to drink directly from Hot Water Tap.

    https://www.youtube.com/watch?v=kAzKts6Wp1Q&t=518s

  • Uh oh i hope it is ive been doing it regularly

  • Most electric hot water tanks have a sacrificial anode down the middle made of magnesium to protect the tank from rusting. This wears away over time as the magnesium is oxidised and dissolved in the water. Not too sure what the effect of extra magnesium intake would be…

    Best off not drinking it and boiling cold water if you are worried.

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