How to Maintain and Electric Water Heater

  • Transcript

    LESLIE: Well, 40 percent of American homes use electricity to heat their water, which means a little electrical know-how is key to uninterrupted hot showers.

    TOM: Here to tell us how to keep that electric water heater doing its job is Richard Trethewey, the plumbing-and-heating contractor on TV’s This Old House.

    Welcome, Richard.

    RICHARD: Hello, guys.

    TOM: Let’s set the record straight here. The device is called a “water heater,” not a hot-water heater, because that would be redundant.

    RICHARD: Oh, you’re such a stickler.

    TOM: But you know what? They operate quite differently than their gas counterpart. What’s the most important thing to know about these devices? Where are they most likely to break down or stop producing that hot water?

    RICHARD: Well, let’s do a little bit of definition. A gas tank-type water heater has a gas burner at the bottom.

    TOM: Right.

    RICHARD: It has a flue pipe up through the center. It has to be vented to outside or into a chimney somehow. An electric water heater has two electrical elements: these resistance electrical heaters that you would actually find if you look carefully inside of the – a coffee maker, a coffee machine. And it has no vent at all. It’s just a super-insulated thermos bottle. So you can stick them anywhere. They both – gas or electric – still have a hot and a cold pipe coming out through the top of them and they have a drain at the bottom. But that’s where the similarities end.

    TOM: So those electric elements is how the water actually gets warm. Is that something that breaks down? Do these elements burn out like any other type of heating coil might?

    RICHARD: You know, when you’re heating cold water, it’s got lime or scale or magnesium. There’s all sorts of things that can be in it. And what can happen over time is it can – that can – whatever the impurity is in the water can bond to the hottest surface you can find, which is these elements.

    So a tank-type water heater generally has two elements: one at the bottom, one at the top. And there’s a thermostat that’ll sense the temperature in the tank and determine when to bring on those elements. Now, there’s also a safety device called an ECO, so the combination of these devices – the electrical elements, the thermostat and the ECO – will give you the right water temperature, we hope.

    But if an element fails, the symptom is going to be that the water heater is – the water’s warm. But it’s not really hot. It might be that one of the elements have failed. And so, for that case, you want to – with safety, you want to have a tester but you want to be able to go and check – is there continuity on the element? Is the element failed? And so you start by – with the appropriate tester, find out just where power exists.

    A tank-type water heater – electrical tank-type water heater – will not use the 110 volts that you see coming out of your electric outlets in the wall. It’s 220. So it’s much more power in order to be able to heat that water.

    TOM: So, of course, you turn off the power to the unit and then you check the continuity across the coil and make sure that it’s solid.

    RICHARD: That’s right. Absolutely. Yeah, yeah. They can. Again, if they make replacement elements, they come in different sizes to support the amount of power you’re trying to – hot water you’re trying to make. And sometimes, though, if you wait until the ninth or tenth year, sometimes where that element connects into the tank is also corroded. You look inside there, you’ll see leaks starting to be around where that element goes in there. At that point, you make the decision it’s not worth trying to just put bad money after good and you get a new water heater.

    TOM: Now, are there other ways to deliver hot water through an electric water heater, aside from the coils? Are there different technologies that are out there today that are perhaps more efficient than that very simple system?

    RICHARD: Well, everyone wants to ask and find out – is there an electric instantaneous water? Is there something that I can just stick on a wall and open up a faucet and get hot water when I need it? And the answer is yes but the answer is a much longer one and that is you need to have a lot of electricity available to be able to do it instantaneously at a point of use. And the other thing is that they just haven’t proven to last.

    With the water quality we have in this country with lime or scale, it seems that just at the point you’re starting to enjoy this thing two or three years in, the electrical elements have absorbed and caked on with all this element and the elements burn out. So I wish there was one I could recommend but right now …

    LESLIE: Oh, I can remember our fancy 80s makeover kitchen that my parents had done.

    RICHARD: Yeah.

    LESLIE: We had one of the little instant hot waters at the sink.

    RICHARD: Oh, yeah.

    LESLIE: So you could have tea or Sanka immediately.

    RICHARD: Yeah. Oh, yeah. Yeah, yeah, yeah. No, those didn’t last. But they actually fall out of favor but I love them. So I love being able to just get a hot cup of tea all the time. Tommy Silva still talks about his. He loves his, too.

    TOM: Now, what about heat-pump technology? There’s heat-pump water heaters today.

    RICHARD: That’s got a story. That’s got a story. That heat pump says, “I’m not going to have – rely strictly on electrical elements to heat the water and super heat it like that coffee maker we talked about.” I’m going to say, “Look, there’s heat that’s available around me in the mechanical room. I’m going to gather it in through the equivalent of an air conditioner that works in reverse, gather that heat and then deliver it down into the tank filled with water.”

    And those are – they call them “hybrid water heaters.” They have an unbelievable story about – from an energy standpoint compared to electrical. And the new energy standards in this country, in April of 2015, really push hard to – for people not to do standard in anything over 52 or 66 gallons, in the larger sizes. You have to do a hybrid now because it’s too wasteful to be a standard electric water heater.

    TOM: Fantastic information. Richard Trethewey, the plumbing-and-heating contractor on TV’s This Old House, thank you so much for being a part of The Money Pit.

    RICHARD: Trying to keep you out of hot water.

    TOM: Or in it.

    RICHARD: That’s right.

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