5 ms·

On a related note, I wonder if people around the world are familiar with electric showers. Essentially, it's a resistance similar to the one found in a toaster,

On a related note, I wonder if people around the world are familiar with electric showers. Essentially, it's a resistance similar to the one found in a toaster, placed right inside the showerhead. It heats the water as it flows through. People hearing about it for the first time are usually shocked that we don't die from electrecution.

kkielhofner 2y ago
I remember seeing my first of these in a small beachside hotel (pousada) in Brasil. In this case the wiring was over-stripped and copper was exposed at the shower head. I used it but I was very, very careful not to splash…
yourusername 2y ago
I still wonder how electrocution is not a big issue. My local electricity codes say absolutely no electricity within zone 0. I get a bit nervous about hooking up IP 65 rated lights to a IP X4 rated switchbox a meter away from the shower head
- Alupis 2y ago
  There's a reason you don't see this type of water heater in most of the world.
  - mikedelfino 2y ago
    I wonder, though, why there are so few incidents where this type of shower is prevalent, given that people not used to it are so worried. If the fatality rate were 0.0001%, hundreds of people would die every day.
    - Alupis 2y ago
      Just in this thread alone we've found several stories of people being mildly shocked by these devices while on vacation. It's not that people die every day from these devices, it's that in general this isn't a great way to heat water if you have alternatives available. I don't know about you, but I would prefer not to receive a shock, no matter how minor it might be, when I step into the shower...
  - kragen 2y ago
    yes, and that reason is mostly the kind of people who were asking the original poster how he made it to adulthood
    - Alupis 2y ago
      Right, I'm sure it has nothing to do with the plethora of "shocking" tales regarding these water heaters. I can count on zero hands the number of times my shower has given me a jolt, even a minor one. We mostly see these types of devices in relatively poor countries without the means to install more modern and safer alternatives, such as whole house water heaters.
      - kragen 2y ago
        no? i mean it's the same reason most people in the usa don't have a bidet in their house; it's not because they're too poor to afford one. technology adoption is path-dependent and mostly random, and fear makes people conservative. yes, there are a few people who are familiar with the actual risks and rewards of the different technologies, but they're vastly outnumbered by the pre-galilean minds who are entirely guided by conventional wisdom most people in the usa can count on zero hands the number of times they've sprayed water on the bathroom ceiling from their bidet, too
        Alupis 2y ago
        This assumes a bidet is objectively better than a regular toilet. That is debatable. It's not debatable these electric showerheads are objectively better, just because some poorer communities around the world use them.
        kragen 2y ago
        well, it only assumes that bidets are subjectively better to many people, which they certainly are; it doesn't rely on the assumption of an objective, observer-independent scale of valuation in the way you're describing (bidets aren't an alternative to a regular toilet, and the fact that you think they are is a minor indicator of why it's difficult for even widespread, highly beneficial innovations to become universal even after centuries) not only is it debatable whether or not electric showers are better in that sense, i have in fact debated it; i refer you to https://news.ycombinator.com/item?id=41250642 https://news.ycombinator.com/item?id=41250642 and eagerly await your opinion
- michaelt 2y ago
  Electric showers are very common in the UK - although the heater is in a wall-mounted unit, with the head on a hose, rather than the heater being in the head itself. The heating element has three layers - innermost, a wire that gets hot. Around that, a ceramic insulator. And outermost, a metal cover to protect the ceramic insulator. Then the heating element is mounted in a small water tank. And that, along with some other components, is put into a suitably waterproof outer plastic box. The insulation is of course all tested at the factory. The tank, heating element outer, and all the pipework in the general vicinity is then grounded, and the power supply passes through an RCD (our equivalent to a GFCI). There are also two or three temperature sensors, and a water pressure sensor. Installers also have to have an up-to-date electrical safety license - so for they know better than to (for example) compromise the waterproofing of the enclosure by adding extra holes to make the wiring simpler.
  - kragen 2y ago
    i'm pretty sure that the electric showers i've used didn't have the sealed magnesia insulating layer you're describing, nor were they connected to an rcd/gfci i do agree that the measures you're describing would make them much safer
  - mikedelfino 2y ago
    In some countries, electric showers use a metal coil as a heating element, similar to a spring, located directly in the showerhead. When you turn on the faucet, water fills the showerhead and touches the metal, effectively bringing the positive and negative wires into contact. The coil then heats the water as it flows out. Occasionally, the coil can oxidize or break if there's not enough water running to keep it cool. When that happens, most people replace it themselves.
  - extraduder_ire 2y ago
    A lot of things involving electricity in places with type-G plugs seem more dangerous if you don't know/assume that almost everything is grounded. Took me a while to realize that hairdrier he mentioned in the blogpost likely didn't have a ground connection in the plug. In the case of a toaster with a grounded frame, the most likely route for a short is straight to earth which will trip the RCD on that set of plugs.
- alvah 2y ago
  Your local codes almost certainly say no electrical outlets in that zone, not no electricity. The assumption being hardwired devices installed by professionals are not a huge risk.
- userbinator 2y ago
  Electricity takes the path of least resistance. If things are done right, that means through the metal heating element and the ground wire, and not through your body.
  - mistercow 2y ago
    This is a dangerous myth. Electricity takes all available paths, with less current flowing through the paths with greater resistance. As far as I understand, the main reason people don’t get electrocuted even with improperly grounded shower head heaters is that (as noted in the post), tap water is generally not very conductive in the first place, so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law.
    - userbinator 2y ago
      It's not a myth. Your second paragraph basically agrees with me and contradicts itself. so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law. That is, by definition, NOT the "least resistance path".
      - mistercow 2y ago
        > It's not a myth. Yes it is. A tip: if someone tells you something is a myth, your next step should be to google it. This is intro level parallel circuit stuff. Hell, just think about the circuitry in your house. If you have your phone charging on one outlet, and you plug a hair dryer into the adjacent outlet, does the phone stop charging? Does the hair dryer not run? Do you think those things have exactly equal resistance? Of course not. Current flows to both of them, but more current flows to the hair dryer. > That is, by definition, NOT the "least resistance path". I don’t think you know what “by definition” means. You could be the only path for the electricity to flow, and if there’s high enough resistance, it won’t hurt you. Please stop repeating this nonsensical folk wisdom. It can get people killed.
MathMonkeyMan 2y ago
I was literally shocked at a hostel in Nicaragua because whoever installed the heater didn't ground it. Those electrons wanted that sweet, positively charged earth and I was the fastest way to get there. I don't know if the circuit was through the running water or if it was the metal tap handles, but it was quite a jolt. edit: Now that I try to remember it, it was definitely either the tap handle or the metal pipes. ZAP.
- practicemaths 2y ago
  Made me think of Electroboom's visit to Mexico. https://youtu.be/d1mPemYUrVc?si=C9zfy6jQJaO3BZ7e https://youtu.be/d1mPemYUrVc?si=C9zfy6jQJaO3BZ7e
  - ASalazarMX 2y ago
    As a Mexican, I can confirm. I received my house with half the grounded outlets actually not grounded. Fun times.
  - lucb1e 2y ago
    Nontracking link: https://youtu.be/d1mPemYUrVc https://youtu.be/d1mPemYUrVc
    - autoexec 2y ago
      "less tracking" might be better as there's no link you can follow to youtube that won't result in you being tracked.
- snozolli 2y ago
  A soldier died in Iraq in 2008 because a water pump wasn't grounded. https://www.cnn.com/2009/US/07/27/military.electrocutions/ https://www.cnn.com/2009/US/07/27/military.electrocutions/
- adamcharnock 2y ago
  Same experience in a Costa Rica hostel! Except in that case my skin just gently tingled where the water touched it. It was a case of, “I know that sensation, and I certainly shouldn’t be feeling it in the shower”
hammock 2y ago
Yeah I used one in Costa Rica... it was shocking me the whole time. I didn't realize until after my shower what was going on.
Tomis02 2y ago
> People hearing about it for the first time are usually shocked
hooverd 2y ago
I'd hope they're grounded correctly.
- mikedelfino 2y ago
  Next, you'd hope that houses have proper ground wires instead of empty holes for the third pin. :)
  - throwway120385 2y ago
    In the US you're also allowed to use an ungrounded GFCI if you need to retrofit an existing electrical circuit and the ground wire wasn't provided originally.
    - mauvehaus 2y ago
      I believe in this case, it also has to be labeled "no equipment ground". IANAE
      - throwway120385 2y ago
        It's true, but IME people don't label it.
kragen 2y ago
i've been shocked by an electric shower, in perú. the hotel gave me a different room. normally the metal case around the heating element is grounded, which prevents this i don't remember ever seeing one here in argentina (perhaps they're illegal), but they're common in many countries
YeGoblynQueenne 2y ago
I have one of those at home in the UK, in fact I only recently changed the older unit that was getting long in the tooth. The house is old and an electric shower the only way to have a proper shower. I also have a shower extension, a rubber tube with two inputs you connect to the hot and cold taps in the bath tub and which outputs cold water if you hold it lower than the taps and hot water if you keep it above the taps, but never a mix of the two. For those who don't know, the sinks and bathtubs in UK homes and businesses often have two completely separate taps: one for hot, one for cold. You're supposed to fill the sink with water from both and "wash" your hands (or your dishes) in it. No, you don't rinse them afterwards. It's just soap, it's good for you.
- bornfreddy 2y ago
  > It's just soap, it's good for you. Sorry, but I really can't tell - was that sarcasm?
  - simonh 2y ago
    Oh yes.
  - YeGoblynQueenne 2y ago
    Yes. The point is that it's not just soap but soapy water that has just washed off all kinds of gunk and dirt off your hands or dishes. It's a good idea to rinse it off. But, apparently, that's not the done thing in certain sectors of British society, e.g. see: I wash up like a normal person: I fill a sink with hot water and washing-up liquid, and scrub the dishes in order of what needs the least attention. Glasses need a quick wipe and then they’re put aside, while the cutlery has a nice little soak at the bottom. You finish with the pans. If at any point the bubbles are not sparkling white, the water is dirty and needs to be refilled. I then move the dishes to the drying rack, without rinsing them off. In my opinion, this is the cleanest, most hygienic way of doing things, because everything has a little bath in the sink. https://amp.theguardian.com/lifeandstyle/2022/may/06/you-be-the-judge-should-my-partner-soak-the-dishes-before-washing-up https://amp.theguardian.com/lifeandstyle/2022/may/06/you-be-... To be fair, dish washing turns out to be a very controversial thing. When I was doing my degree I lived in a shared student house with a British girl who was muslim, a Chinese girl and a British girl of unknown religion. The Chinese girl and I always insisted on re-doing the dishes after the second British girl did them the "normal" way as above. Then the muslim girl did them all over again with her own sponge to make sure they hadn't touched pork. But nobody picked up the used loo roll tubes from the bathroom. They piled up like abstract art :D
charles_f 2y ago
I saw one of these on electro boom, he was almost disappointed not to die

kkielhofner 2y ago

I remember seeing my first of these in a small beachside hotel (pousada) in Brasil. In this case the wiring was over-stripped and copper was exposed at the shower head. I used it but I was very, very careful not to splash…

yourusername 2y ago

I still wonder how electrocution is not a big issue. My local electricity codes say absolutely no electricity within zone 0. I get a bit nervous about hooking up IP 65 rated lights to a IP X4 rated switchbox a meter away from the shower head

Alupis 2y ago
There's a reason you don't see this type of water heater in most of the world.
- mikedelfino 2y ago
  I wonder, though, why there are so few incidents where this type of shower is prevalent, given that people not used to it are so worried. If the fatality rate were 0.0001%, hundreds of people would die every day.
  - Alupis 2y ago
    Just in this thread alone we've found several stories of people being mildly shocked by these devices while on vacation. It's not that people die every day from these devices, it's that in general this isn't a great way to heat water if you have alternatives available. I don't know about you, but I would prefer not to receive a shock, no matter how minor it might be, when I step into the shower...
- kragen 2y ago
  yes, and that reason is mostly the kind of people who were asking the original poster how he made it to adulthood
  - Alupis 2y ago
    Right, I'm sure it has nothing to do with the plethora of "shocking" tales regarding these water heaters. I can count on zero hands the number of times my shower has given me a jolt, even a minor one. We mostly see these types of devices in relatively poor countries without the means to install more modern and safer alternatives, such as whole house water heaters.
    - kragen 2y ago
      no? i mean it's the same reason most people in the usa don't have a bidet in their house; it's not because they're too poor to afford one. technology adoption is path-dependent and mostly random, and fear makes people conservative. yes, there are a few people who are familiar with the actual risks and rewards of the different technologies, but they're vastly outnumbered by the pre-galilean minds who are entirely guided by conventional wisdom most people in the usa can count on zero hands the number of times they've sprayed water on the bathroom ceiling from their bidet, too
      - Alupis 2y ago
        This assumes a bidet is objectively better than a regular toilet. That is debatable. It's not debatable these electric showerheads are objectively better, just because some poorer communities around the world use them.
        kragen 2y ago
        well, it only assumes that bidets are subjectively better to many people, which they certainly are; it doesn't rely on the assumption of an objective, observer-independent scale of valuation in the way you're describing (bidets aren't an alternative to a regular toilet, and the fact that you think they are is a minor indicator of why it's difficult for even widespread, highly beneficial innovations to become universal even after centuries) not only is it debatable whether or not electric showers are better in that sense, i have in fact debated it; i refer you to https://news.ycombinator.com/item?id=41250642 https://news.ycombinator.com/item?id=41250642 and eagerly await your opinion
michaelt 2y ago
Electric showers are very common in the UK - although the heater is in a wall-mounted unit, with the head on a hose, rather than the heater being in the head itself. The heating element has three layers - innermost, a wire that gets hot. Around that, a ceramic insulator. And outermost, a metal cover to protect the ceramic insulator. Then the heating element is mounted in a small water tank. And that, along with some other components, is put into a suitably waterproof outer plastic box. The insulation is of course all tested at the factory. The tank, heating element outer, and all the pipework in the general vicinity is then grounded, and the power supply passes through an RCD (our equivalent to a GFCI). There are also two or three temperature sensors, and a water pressure sensor. Installers also have to have an up-to-date electrical safety license - so for they know better than to (for example) compromise the waterproofing of the enclosure by adding extra holes to make the wiring simpler.
- kragen 2y ago
  i'm pretty sure that the electric showers i've used didn't have the sealed magnesia insulating layer you're describing, nor were they connected to an rcd/gfci i do agree that the measures you're describing would make them much safer
- mikedelfino 2y ago
  In some countries, electric showers use a metal coil as a heating element, similar to a spring, located directly in the showerhead. When you turn on the faucet, water fills the showerhead and touches the metal, effectively bringing the positive and negative wires into contact. The coil then heats the water as it flows out. Occasionally, the coil can oxidize or break if there's not enough water running to keep it cool. When that happens, most people replace it themselves.
- extraduder_ire 2y ago
  A lot of things involving electricity in places with type-G plugs seem more dangerous if you don't know/assume that almost everything is grounded. Took me a while to realize that hairdrier he mentioned in the blogpost likely didn't have a ground connection in the plug. In the case of a toaster with a grounded frame, the most likely route for a short is straight to earth which will trip the RCD on that set of plugs.
alvah 2y ago
Your local codes almost certainly say no electrical outlets in that zone, not no electricity. The assumption being hardwired devices installed by professionals are not a huge risk.
userbinator 2y ago
Electricity takes the path of least resistance. If things are done right, that means through the metal heating element and the ground wire, and not through your body.
- mistercow 2y ago
  This is a dangerous myth. Electricity takes all available paths, with less current flowing through the paths with greater resistance. As far as I understand, the main reason people don’t get electrocuted even with improperly grounded shower head heaters is that (as noted in the post), tap water is generally not very conductive in the first place, so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law.
  - userbinator 2y ago
    It's not a myth. Your second paragraph basically agrees with me and contradicts itself. so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law. That is, by definition, NOT the "least resistance path".
    - mistercow 2y ago
      > It's not a myth. Yes it is. A tip: if someone tells you something is a myth, your next step should be to google it. This is intro level parallel circuit stuff. Hell, just think about the circuitry in your house. If you have your phone charging on one outlet, and you plug a hair dryer into the adjacent outlet, does the phone stop charging? Does the hair dryer not run? Do you think those things have exactly equal resistance? Of course not. Current flows to both of them, but more current flows to the hair dryer. > That is, by definition, NOT the "least resistance path". I don’t think you know what “by definition” means. You could be the only path for the electricity to flow, and if there’s high enough resistance, it won’t hurt you. Please stop repeating this nonsensical folk wisdom. It can get people killed.

MathMonkeyMan 2y ago

I was literally shocked at a hostel in Nicaragua because whoever installed the heater didn't ground it. Those electrons wanted that sweet, positively charged earth and I was the fastest way to get there. I don't know if the circuit was through the running water or if it was the metal tap handles, but it was quite a jolt. edit: Now that I try to remember it, it was definitely either the tap handle or the metal pipes. ZAP.

practicemaths 2y ago
Made me think of Electroboom's visit to Mexico. https://youtu.be/d1mPemYUrVc?si=C9zfy6jQJaO3BZ7e https://youtu.be/d1mPemYUrVc?si=C9zfy6jQJaO3BZ7e
- ASalazarMX 2y ago
  As a Mexican, I can confirm. I received my house with half the grounded outlets actually not grounded. Fun times.
- lucb1e 2y ago
  Nontracking link: https://youtu.be/d1mPemYUrVc https://youtu.be/d1mPemYUrVc
  - autoexec 2y ago
    "less tracking" might be better as there's no link you can follow to youtube that won't result in you being tracked.
snozolli 2y ago
A soldier died in Iraq in 2008 because a water pump wasn't grounded. https://www.cnn.com/2009/US/07/27/military.electrocutions/ https://www.cnn.com/2009/US/07/27/military.electrocutions/
adamcharnock 2y ago
Same experience in a Costa Rica hostel! Except in that case my skin just gently tingled where the water touched it. It was a case of, “I know that sensation, and I certainly shouldn’t be feeling it in the shower”

hammock 2y ago

Yeah I used one in Costa Rica... it was shocking me the whole time. I didn't realize until after my shower what was going on.

Tomis02 2y ago

> People hearing about it for the first time are usually shocked

hooverd 2y ago

I'd hope they're grounded correctly.

mikedelfino 2y ago
Next, you'd hope that houses have proper ground wires instead of empty holes for the third pin. :)
- throwway120385 2y ago
  In the US you're also allowed to use an ungrounded GFCI if you need to retrofit an existing electrical circuit and the ground wire wasn't provided originally.
  - mauvehaus 2y ago
    I believe in this case, it also has to be labeled "no equipment ground". IANAE
    - throwway120385 2y ago
      It's true, but IME people don't label it.

kragen 2y ago

i've been shocked by an electric shower, in perú. the hotel gave me a different room. normally the metal case around the heating element is grounded, which prevents this i don't remember ever seeing one here in argentina (perhaps they're illegal), but they're common in many countries

YeGoblynQueenne 2y ago

I have one of those at home in the UK, in fact I only recently changed the older unit that was getting long in the tooth. The house is old and an electric shower the only way to have a proper shower. I also have a shower extension, a rubber tube with two inputs you connect to the hot and cold taps in the bath tub and which outputs cold water if you hold it lower than the taps and hot water if you keep it above the taps, but never a mix of the two. For those who don't know, the sinks and bathtubs in UK homes and businesses often have two completely separate taps: one for hot, one for cold. You're supposed to fill the sink with water from both and "wash" your hands (or your dishes) in it. No, you don't rinse them afterwards. It's just soap, it's good for you.

bornfreddy 2y ago
> It's just soap, it's good for you. Sorry, but I really can't tell - was that sarcasm?
- simonh 2y ago
  Oh yes.
- YeGoblynQueenne 2y ago
  Yes. The point is that it's not just soap but soapy water that has just washed off all kinds of gunk and dirt off your hands or dishes. It's a good idea to rinse it off. But, apparently, that's not the done thing in certain sectors of British society, e.g. see: I wash up like a normal person: I fill a sink with hot water and washing-up liquid, and scrub the dishes in order of what needs the least attention. Glasses need a quick wipe and then they’re put aside, while the cutlery has a nice little soak at the bottom. You finish with the pans. If at any point the bubbles are not sparkling white, the water is dirty and needs to be refilled. I then move the dishes to the drying rack, without rinsing them off. In my opinion, this is the cleanest, most hygienic way of doing things, because everything has a little bath in the sink. https://amp.theguardian.com/lifeandstyle/2022/may/06/you-be-the-judge-should-my-partner-soak-the-dishes-before-washing-up https://amp.theguardian.com/lifeandstyle/2022/may/06/you-be-... To be fair, dish washing turns out to be a very controversial thing. When I was doing my degree I lived in a shared student house with a British girl who was muslim, a Chinese girl and a British girl of unknown religion. The Chinese girl and I always insisted on re-doing the dishes after the second British girl did them the "normal" way as above. Then the muslim girl did them all over again with her own sponge to make sure they hadn't touched pork. But nobody picked up the used loo roll tubes from the bathroom. They piled up like abstract art :D

charles_f 2y ago

I saw one of these on electro boom, he was almost disappointed not to die