My water heater stopped working today.

[hrhofmann]

Chris

Do you have a voltmeter that can measure 240 Volts??

[Red Green]

"WW" wrote in news:GeGdnQe0kIk9rPPWnZ2dnUVZ [e-mail]:

If you are an ex appliance person then you should know THE BOTTOM ONE WILL COME ON FIRST under normal operation. As an appliance service person, what percent of the time did you find the bottom element bad compared to the upper one? Maybe 80-90? The bottom element comes on to some extent to heat ALL water. The top doesn't. Sediment is not always the cause of lower failure.

The condition I itemized is normal operation.

Look at the full document with text from the same reference:

It even says bottom on first on the second page under "Normal operation" in the first paragraph. The second paragraph states on high demand it switches to the top. Then it switches back to the bottom to complete heating before totally going off.

If the tank has been off then that is an Initial Startup state. That's on page 1.

Under normal operation, the lower element comes on first because cold water is being pumped into the bottom of the tank. Not because hot water is being drawn off the top and it gets colder than the bottom.

So is RBM right? Well, yes and no. It would come on first if the tank was cold to start with.

As a second reference to support what I say, I have personally put two meters on the elements simultaneously and watched how the elements sequence.

[RBM]

You need to re read the article. It very clearly says that the upper heats first, then the lower. If you look at the diagram, it's apparent that the lower thermostat doesn't even get the second leg of the 240 volts until the upper is satisfied

[Van Chocstraw]

It's not likely that both heating elements would go bad at the same time. If one shorted, the one with the popped breaker, disconnect it and reset the button. The bottom element should still work or vice versa. One is bad, the other is still good. Determine the bad one. and run with a single until you can repair it.

[Van Chocstraw]

It's not likely that both heating elements would go bad at the same time. If one shorted, the one with the popped breaker, disconnect it and reset the button. The bottom element should still work or vice versa. One is bad, the other is still good. Determine the bad one. and run with a single until you can repair it.

[RBM]

If the upper element was bad, which there is no indication of, the lower element wouldn't get any power , since the upper thermostat must be satisfied first, before sending power to the lower thermostat

[trader4]

I think you two guys are actually saying the same thing and somehow missing each others points. Let me summarize how I think they work:

Only one element is on at a time.

The upper element has priority, so if the water at the top of the tank drops below the thermostat setting, that element will be on, disabling the lower element.

If water is drawn, provided the upper water temp is still above the upper thermostat setting, the lower thermostat will drop below it's turn on point from the incoming cold water at the bottom of the tank, turning on the lower element.

If you continued to draw a lot of water, eventually the supply of hot water will diminish enough so the upper thermostat will drop below it's setting. That will turn off the lower element and turn on the upper one. The obvious intent here is to try to now heat the water at the top of the tank which is going out first.

[trader4]

Agree.

[Red Green]

"RBM" wrote in news:4b6eb78b$0$31261$ [e-mail]:

Yes it does clearly say that - under the Initial Startup section. In a properly working tank this only happens once - when the tank is started from a cold/ambient state. All other times it follows the Normal Operation section

"the bottom thermostat closes and the element will begin to heat the cold water."

It depends on the initial condition.

Yes, the upper must be satisfied first before the lower will come on.

Under NORMAL operation, repeat, NORMAL operation, the lower will come on first.

If your tank is hot and no elements are on and you put a meter on the lower and upper element and turn on some hot water in the house until the water heater kicks on...if the upper element comes on first you have a bad lower element, defective thermostat, or broken dip tube.

** There is a difference between which must be satisfied first and which comes on first.** The upper must always be satisfied first. The fact it it is usually already satisfied when the lower kicks on. Examples would be normal useage of tap water or normal heat loss to surroundings. Run a washer with hot water or a shower (high demand) and you will see the bottom come on, bottom kick off and top on, top kick off and bottom on then both off.

The only way you will be convinced it to do the things with the meters as I have done on multiple electric water heaters.

[RBM]

The OP has no hot water. I gave him the sequence of events to try to understand how the heater functions. You replied to me, telling me that the lower element heats first. You're wrong. Then you try to justify your position by claiming "under normal operation". "Normal operation" doesn't begin until the upper element first heats the water.

[Van Chocstraw]

Disconnect the top and jump it, do I have to hold your hand?

[Ron in NY]

---------------------------------------------------------------------------------------------------------- The same thing happened to me a number of years ago--extremely hot water and then no hot water with the reset button on the upper thermostat popped out. It turned out to be a lower element that had grounded itself out. The lower element has 120 volts applied to each end of the element all the time, for a total voltage of 240, unless the water has gotten so cold that the upper thermostat closes to heat up the upper part of the tank and disconnects power to the lower element. What is now happening is the lower element is heating the water until the upper thermostat pops on safety sensing extremely hot water. The current in the lower element is not flowing from one end of the element to the other end, but it is flowing from one end to ground and is constantly heating the water without regard to the lower thermostat. Disconnect all power th the unit, and disconnect the 2 wires to the lower element. Measure the resistance from each screw of the lower element to the bare metal around the hole where the element is installed. The resistance should be infinite---You will find that 1 screw is grounded to the tank due to the element being shorted internally. Replace the lower element and your problem will be solved.

RON ======================================================== Remove the ZZZ from my E-mail address to send me E-mail.

[RBM]

You were addressing someone that doesn't have my experience. You didn't tell him to disconnect the top and jump it, you implied that it would "run with a single". You don't have to hold my hand, but it would probably help the OP, if you clarified what you meant

[clare]

From John Wood manual: Normal Operation: When hot water is being used, cold water enters the bottom of the heater (either through the bottom inlet nipple or the dip tube), the bottom thermostat closes and the element will begin to heat the cold water.

When a significant amount of hot water has been used, the upper thermostat will take priority and heat up the top portion of the heater. Once heated, it will flip/switch power down to the lower thermostat and heat the lower portion.

High Limit Control: All electric water heaters are supplied with a high limit control switch. This switch is a safety device designed to shut the unit off if it over heats and the water reaches an unsafe temperature. Power to the thermostats and elements is completely cut off when it trips. The high limit control can be reset by firmly pushing on the red button above the upper thermostat. An audible click can be heard when it resets. If the high limit control trips frequently it is an indication of additional problems. Contact a qualified technician for service. (end quote)

The red button is the high limit. If the high limit or the upper element goes open you get NO HEAT. If the lower element goes open you get reduced capacity and slower reheat. If the

[clare]

I would second that diagnosis. A "grounded" lower element is virtually the ONLY thing that can cause the described sequence of events - the only thing that would cause uncontrolled heating, which would then trigger the safety shotoff.

[clare]

And the chances that this IS the problem are extremely remote. The proper short-term solutuion is to totally disconnect the lower element which will allow the upper element to heat the top of the tank, providing roughly 1/3 the reserve of hot water and taking roughly 3 times as long to recover as normal - but he WILL have hot water, and it will NOT trip the overtemp safety untill he can get the lower element replaced.

[Red Green]

[e-mail] wrote in news: [e-mail]:

Exactly.

[Red Green]

"RBM" wrote in news:4b6edd7d$0$22516$ [e-mail]:

I attempted to specify both situations referring to NORMAL operation and the OPs case.

I did not want to mislead anyone, including the OP, that any time the lower element comes on first that there is something wrong. COnsider OP makes the repair, lets it heat then checks things out. Runs some hot water and "Crap, the damn lower element is coming on first."

[Van Chocstraw]

He did say the TOP breaker was popped.

[Tony Hwang]

Hi, Ny take on the problem. One of the thermostat(probably bottom one) got stuck causing two element coming on which tripped safety sensor.