4 ms·

> ever start with a hot tap for water you're gonna boil? I've been told I shouldn't do this, so I don't, but I always feel like a rube waiting for a big pot of

> ever start with a hot tap for water you're gonna boil? I've been told I shouldn't do this, so I don't, but I always feel like a rube waiting for a big pot of pasta water to boil from cold when I know I could have just used my giant tank of heated water and save 10 minutes of waiting...

yamtaddle 4y ago
Yeah, I don't either, but I'd be surprised if most people don't use the hot tap for stovetop-bound water.
anikom15 4y ago
There’s always a chance that there’s a dead animal in your water heater
- gambiting 4y ago
  I mean.....I don't know about elsewhere, but here in UK you just have a combi boiler, there's no storage.
  - anikom15 4y ago
    Anywhere with abundant natural gas (like America) will mostly have tank water heaters powered by gas.
- yamtaddle 4y ago
  I'm torn between wanting more information, and preferring to live in blissful ignorance.
  - gambiting 4y ago
    In old houses if you had a hot water storage tank in the attic it was usually just covered with styrofoam or a metal or wooden slab, it wasn't uncommon for an occasional insect or yes, a small rodent to fall in and die in there. It's one of the reasons why most houses in the UK had separate cold and hot water taps - cold water was considered safe to drink, hot not so much. Nowadays if you have a hot water cylinder it's impossible for anything to get in there(although there is still a chance of bacteria growing inside the tank, but any modern cylinder will periodically heat itself to very high temperature to kill any pathogens)
    - dehrmann 4y ago
      Aren't there occasionally dead animals in NYC rooftop water towers, too? And that's cold water.
  - anikom15 4y ago
    It could be a bird, a bat, or a victim of bipolar disorder. https://en.m.wikipedia.org/wiki/Death_of_Elisa_Lam https://en.m.wikipedia.org/wiki/Death_of_Elisa_Lam
- bmicraft 4y ago
  No, my water runs through a heat exchanger
myshpa 4y ago
I think it's because of the bacteria living in hot water, and some toxins are resistant to boiling.
sitharus 4y ago
That's due to old-fashioned plumbing. Wayyy back in the day when water networks were fairly new they often couldn't provide the water pressure we have now, especially in hilly areas. It was fine for cold water, but not enough to pressurise a hot water tank. The solution was a header tank in the attic. This stored water from the supply and fed it down to the hot water cylinder, providing some pressure. The problem is the header tanks weren't a sealed system so animals could make their way in. In particular when using rodent control poison as this makes them seek water. Generally it'd be noticed pretty quickly, but not immediately. So the hot water was generally safe for washing but shouldn't be used for drinking or cooking. With modern closed systems (from the 70s onwards really) this isn't an issue.
- coolspot 4y ago
  Where I am from we are having centrally-heated water, so we were told that hot tap water has anti-scaling chemicals unlike cold tap water which has only excessive chlorine.
- dabluecaboose 4y ago
  Worth mentioning that hot water is also better at dissolving things than cold, which is why aquarists should avoid putting anything from the hot water tap into their aquariums. It can introduce copper which is bad for my shrimp.
- deleted 4y ago
  [deleted]
- throw0101a 4y ago
  > With modern closed systems (from the 70s onwards really) this isn't an issue. The water department for the City of Denver still recommends not to use hot water: > Hot water systems like tanks and boilers contain metallic parts that corrode as time goes by, contaminating the water. Hot water also dissolves contaminants in pipes faster than cold water. * https://www.denverwater.org/tap/psa-dont-drink-or-cook-with-hot-water-from-the-tap https://www.denverwater.org/tap/psa-dont-drink-or-cook-with-... Also Vancouver (BC): > Confused, I decided to send the question over to Metro Vancouver, which provides water to most of the 2 million residents in the Vancouver region. Bill Morrell, Metro’s media relations guy, quickly got me this answer from Bob Jones, their water quality expert. The bottom line: Use cold water for boiling. * https://vancouversun.com/news/staff-blogs/why-you-shouldnt-use-hot-tap-water-for-drinking-or-cooking https://vancouversun.com/news/staff-blogs/why-you-shouldnt-u... EPA: > 2. USE ONLY COLD WATER FOR COOKING AND DRINKING. Do not cook with, or drink water from the hot water tap. Hot water can dissolve more lead more quickly than cold water. If you need hot water, draw water from the cold tap and then heat it. * https://www.epa.gov/sites/default/files/2015-09/documents/2002_5_17_lcrmr_guidance_lcmr_lead_public_education_poster_v1.pdf https://www.epa.gov/sites/default/files/2015-09/documents/20...

yamtaddle 4y ago

Yeah, I don't either, but I'd be surprised if most people don't use the hot tap for stovetop-bound water.

anikom15 4y ago

There’s always a chance that there’s a dead animal in your water heater

gambiting 4y ago
I mean.....I don't know about elsewhere, but here in UK you just have a combi boiler, there's no storage.
- anikom15 4y ago
  Anywhere with abundant natural gas (like America) will mostly have tank water heaters powered by gas.
yamtaddle 4y ago
I'm torn between wanting more information, and preferring to live in blissful ignorance.
- gambiting 4y ago
  In old houses if you had a hot water storage tank in the attic it was usually just covered with styrofoam or a metal or wooden slab, it wasn't uncommon for an occasional insect or yes, a small rodent to fall in and die in there. It's one of the reasons why most houses in the UK had separate cold and hot water taps - cold water was considered safe to drink, hot not so much. Nowadays if you have a hot water cylinder it's impossible for anything to get in there(although there is still a chance of bacteria growing inside the tank, but any modern cylinder will periodically heat itself to very high temperature to kill any pathogens)
  - dehrmann 4y ago
    Aren't there occasionally dead animals in NYC rooftop water towers, too? And that's cold water.
- anikom15 4y ago
  It could be a bird, a bat, or a victim of bipolar disorder. https://en.m.wikipedia.org/wiki/Death_of_Elisa_Lam https://en.m.wikipedia.org/wiki/Death_of_Elisa_Lam
bmicraft 4y ago
No, my water runs through a heat exchanger

myshpa 4y ago

I think it's because of the bacteria living in hot water, and some toxins are resistant to boiling.

sitharus 4y ago

That's due to old-fashioned plumbing. Wayyy back in the day when water networks were fairly new they often couldn't provide the water pressure we have now, especially in hilly areas. It was fine for cold water, but not enough to pressurise a hot water tank. The solution was a header tank in the attic. This stored water from the supply and fed it down to the hot water cylinder, providing some pressure. The problem is the header tanks weren't a sealed system so animals could make their way in. In particular when using rodent control poison as this makes them seek water. Generally it'd be noticed pretty quickly, but not immediately. So the hot water was generally safe for washing but shouldn't be used for drinking or cooking. With modern closed systems (from the 70s onwards really) this isn't an issue.

coolspot 4y ago
Where I am from we are having centrally-heated water, so we were told that hot tap water has anti-scaling chemicals unlike cold tap water which has only excessive chlorine.
dabluecaboose 4y ago
Worth mentioning that hot water is also better at dissolving things than cold, which is why aquarists should avoid putting anything from the hot water tap into their aquariums. It can introduce copper which is bad for my shrimp.
deleted 4y ago
[deleted]
throw0101a 4y ago
> With modern closed systems (from the 70s onwards really) this isn't an issue. The water department for the City of Denver still recommends not to use hot water: > Hot water systems like tanks and boilers contain metallic parts that corrode as time goes by, contaminating the water. Hot water also dissolves contaminants in pipes faster than cold water. * https://www.denverwater.org/tap/psa-dont-drink-or-cook-with-hot-water-from-the-tap https://www.denverwater.org/tap/psa-dont-drink-or-cook-with-... Also Vancouver (BC): > Confused, I decided to send the question over to Metro Vancouver, which provides water to most of the 2 million residents in the Vancouver region. Bill Morrell, Metro’s media relations guy, quickly got me this answer from Bob Jones, their water quality expert. The bottom line: Use cold water for boiling. * https://vancouversun.com/news/staff-blogs/why-you-shouldnt-use-hot-tap-water-for-drinking-or-cooking https://vancouversun.com/news/staff-blogs/why-you-shouldnt-u... EPA: > 2. USE ONLY COLD WATER FOR COOKING AND DRINKING. Do not cook with, or drink water from the hot water tap. Hot water can dissolve more lead more quickly than cold water. If you need hot water, draw water from the cold tap and then heat it. * https://www.epa.gov/sites/default/files/2015-09/documents/2002_5_17_lcrmr_guidance_lcmr_lead_public_education_poster_v1.pdf https://www.epa.gov/sites/default/files/2015-09/documents/20...