water heater

[Mr. Wizard]

The last couple trips to the cabin the water heater has been acting up. It will have scalding hot water then after a shower it takes all night to heat back up. Is it possible only one element is bad? Is one more likely out than the other? Do the thermostats go out?

[Archerysniper]

Yes it is possible for one element to go out or the thermostat for the element, do you happen to have off peak electric at the cabin, that might be why it takes all night to heat up. If you have a voltmeter that you can test continuity with shut the power off to the heater remove the wire form the elements and test each element if it is good the volt meter will beep telling you it is a complete circit and that the element is good. If you have to replace one or both the old one will have the voltage and kw stamped on it just replace with one rated the same and if one is bad just replace both since you will have the water and power shut off and the heater drained.

[Redlantern]

Yep, one is more likely to go out than the other. The lower one. But as Archie said, might as well replace them both at the same time since you have it shut down and drained. I would save the upper one for a spare (assuming it's good) so you can replace the lower one the next time it goes out.

[BobT]

If the lower one was bad, it shouldn't take "all night" to recover. That's the advantage of dual-element electric water heaters. Since it takes so long to recharge I'd be more suspect of the upper element.

I also don't think I'd agree with replacing both if only the lower one is bad. The reason is that the upper electric heater element should last a very, very, very long time. The lower units are the typical failures because of the dirt, scale, and mineral deposits that settle at the bottom of the tank and eventually bury the element. This reduces the ability of the element to dissipate the heat into the water and the element then overheats and fails. The water essentially is the heat sink for the heater.

If the upper one turns out to be the failed unit, I'd pull the lower one and clean out as much debris as possible while you have the tank drained.

[fishing tech]

If you do have to replace the element or elements, take the info off of the water heater when you go to get the new ones. I had a friend of mine that was replacing elements 1-2 times a year. Turns out the element he took out and got the numbers off of was not the right one for the water heater in the first place. Got the right one now and no problems.

[WingDing2]

I had the same thing happen to me and its really easy to fix.

Get the correct elements from your local hardware or home center.

Shut off water.

Turn off power to water heater.

Drain your water heater.

Take out the upper and lower elements.

Be sure to remove any scale you can from bottom of the inside of water heater I used a scraper and a shop vac.

Install new elements.

turn on water Fill water heater till it comes out overflow safety valve.

close safety valve.

turn on power.

You will have hot water in an hour.

The whole job took me about 2 hours with a trip to the hardware store.