What to do? 1 element: no juice; 1 element: literally burned

[everyfrog]

So, this is a fun one.

Monday: I come home from a 12-day vacation to cold water. Check the circuit, it had tripped, reset the breaker, hot water the next morning. However it was unusually super hot.

Thursday evening: Doing dishes and realize I have no hot water again. Check the circuit board, hadn't tripped. Checked the panels on the hot water itself - top element has no electricity going to it and (here's the fun one) the bottom element look like it had a small electrical fire. AND it still has power going to it right now.

I know the elements trade on and off as to which is heating the water when, but shouldn't the top element still have power going to it?

Soooo.... replace just the elements or just replace the whole tank? Shut off power to the tank ASAP?

Specs: 50 gallon US Craftsmaster, manufactured in 2008. I've replaced the elements at least once, if not twice, in the past seven years. I believe it was the bottom one that was replaced several times.

Thanks!

TR

 

[hj]

I have no idea whether you are doing a proper test on the elements and thermostats, so cannot advise you. If you use "GOOD" elements, you won't have to replace them that often.

 

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[everyfrog]

That's an excellent point, given that the really only true thing I know about electricity is to just shut it off at the breaker. When I did that and poked around the burned element area to try and test things with the multimeter, the charred wires fell apart, so it would be hard to test if the wires are shorted ... but regardless, I'm going to have to replace the element, as the screws on it are pretty much worthless.

I admit I don't really know how to read the multimeter, but I do that one of those 120/240V light up readers that is obviously easy to read. But the power is off to the tank, so that tool doesn't really help me?

What do you mean by "GOOD" elements? Brand? wattage?

TR

 

[Jadnashua]

When you start with a cold tank, the top element turns on until the top area of the tank is hot to give you some hot water quicker. Then, once that thermostat has been satisfied, it switches to the bottom element. Convection tends to keep the top hot, and once the bottom one reaches the set point, it too shuts off. As you use hot water, the cold gets added to the bottom, and that element turns back on. If the upper one reaches it's low point, it will then switch to just the upper one.

The thing that can trip up people is that with 240vac heating elements, depending on how you measure things, you could easily still have voltage there. Most of the thermostats only break one leg of the power, but with 240vac, there's still power being applied, just nowhere for it to go because the circuit is broken. 120vac stuff has voltage on one side and neutral (tied to ground eventually) on the other, and they break the 120vac leg to switch things...IOW, no power there when off, not true with most 240vac circuits, at least in a water heater. But if you measure from it to ground, you'll still have voltage. Confused yet?

WOrking with electricity is dangerous. A little knowledge can kill you. Be careful.

 

[everyfrog]

What's weird is that no hot water was coming out of my faucets this morning. Then I opened the panels, saw the charred elements and wires, turned off the power and started looking closer. An hour or so later I went back upstairs, and had hot water. But it was probably leftover from overnight.

Another funny thing is that the element that was charred was still warm to touch (after I turned off the power, of course), so I don't know if that was from the fire or if it had been working/heating at the time when I shut off the power.

Regardless, I'm not touching it much more. I'm headed out to talk with folks in person more knowledgable about this stuff than me this afternoon.

My end question is: just replace elements/thermostat or replace the tank? The charred element has me worried a bit.

 

[Jadnashua]

Unless the heat damaged the tank's lining (probably not, but that's only an opinion), an electric WH is pretty simple...replacing the elements and thermostats should get it working again. If it charred the power leads and terminals, you can't just tape them up, and that will require finding the right high-temperature materials. Depending on your skills or the labor costs and the age of the existing tank, labor could be about the same to replace it verses repairing it. If you can just install new components and the wiring is intact, probably cheaper to repair. It's not an exact science.

 

[Jadnashua]

Unless the heat damaged the tank's lining (probably not, but that's only an opinion), an electric WH is pretty simple...replacing the elements and thermostats should get it working again. If it charred the power leads and terminals, you can't just tape them up, and that will require finding the right high-temperature materials. Depending on your skills or the labor costs and the age of the existing tank, labor could be about the same to replace it verses repairing it. If you can just install new components and the wiring is intact, probably cheaper to repair. It's not an exact science.

Site is doing weird things again...cant' get rid of the double post, and response is slow...all I tried to do was edit, and instead, it reposted what was already there...

Anyway, it sounds like the thermostats are working...once the whole tank cools off enough, it will switch to the upper element, and that will heat the top of the tank. Otherwise, the bottom one would try to cycle on and off to maintain the whole tank. So, not until the whole thing cools off would the top turn on...that could take awhile.

 

[everyfrog]

After I explained in greater detail and showed the pictures, the guy at the big box store said to start with replacing the elements and thermostats first, sit in front of the tank for 20-30 minutes and monitor it, make sure nothing happens. He said he was a little nervous about recommending that but to try the cheap fix first (which, now that i think about it, makes me nervous a bit).

But replace those components first and, then you'd know real fast if you need a new tank or not.

So, yay, a date tonight with a hose and the element wrench.

 

[Jadnashua]

You might not lose a lot of water when you pull out the element as long as all of your hot faucets are closed and the cold inlet is shut. Think finger over the end of a straw. IOW, you may not need to drain it first, but be prepared for some water to come out. Be ready to put the new one in without delay, though, or screw the old one back in if there's a big leak. If no water is coming in, and air can't easily get in to replace the lost water....

 

[hj]

Unless the tank is leaking, changing those four items will restore the tank, although it is the "quick and dirty" way to avoid proper testing. AND, most 'kits" come with "poor"elements which can fail in a matter of weeks, sometimes.

 

[everyfrog]

So I think I have bigger problems in that I do think that the tank is leaking. Looking at the bottom element and thermostat area, the metal clip that holds the thermostat in place is rusted. Plus one of the wires has corrosion about 3 inches up the wire. When I pulled the wire away from the element, I peeled black the burnt plastic and found the obvious signs of corrosion of the wire. I'll try and post a pic.

 

[Terry]

If you have a leak, that can cause things to short out.
And............a leaking tank sounds like a bad tank.
Or at least a leak at the top connections that need looking at.

 

[hj]

That "corrosion" llooks more like "melted insulation" from high resistance caused by a loose connection.

 

[Master Plumber Mark]

why dont you just change the damn water heater

 

[Edwardh1]

my 2008 rheum looked the same, lots of water from condensation I think where is this heater? under house?