what happens to an electric water heater when you turn it on before the tank is completely full?

Depends upon how full it is. If the water level is above the upper heating element, then no harm will be done at all. If not, there's a good chance that the upper element will burn out quickly. Since the upper element comes on first when the tank is cold, there is a good chance that it might need to be replaced. If it is a new unit, you will probably be OK.

---Ed---

no hot water if the upper element was dry fired.White chalky looking stuff coming out the hot side.unusual feel as you back the melted element out of the heater.In rare cases electrical ground shorts to wiring or components.

water heater was new

the heater was almost full, but i heard some noises...water heater is only luke warm now...it wont heat fully.

i dont repair them, so a repair guy is going over to fix it tomarrow...im hoping its just an element replacement.

is there any way for the repair plumber to tell if it was dry fired?

i was in too much of a hurry and its going cost me.

Upper element could have failed when cold water submerged it?



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If you did not smell electronics melting .upper element and good to go.Unless he goes fishing for melt down parts.Better to get them out at the heater than from the fixtures or tubing.

Wauke, you should learn how to troubleshoot water heaters. You could really save yourself a lot of headache if you knew how to do it. I can't speak about the powervent water heaters because there are none of them in my area, but standard gas and electric water heaters are very simple to deal with, and require only a handful of parts.

As for your question, it sounds like you burnt out the top element. Should take under 30 minutes to fix in most situations.

If it isn't getting fully-heated, then yes, you have lost the upper element. The lower one won't kick in until the upper one (upper half of the tank of water) is satisfied with regard to temperature. Under normal circumstances, once this has occurred, the power is thrown to the lower element. That doesn't appear to be happening.

Since you say that you are getting some heated water, my guess is that the upper element is ruined and you are getting a little bit of heat from what is left of it to ground. More than likely, what is left of the upper element is now running on 120 volts (to ground) and won't produce enough heat to be measurable. The lower element could heat the entire tank at a much lower recovery rate, but that can't happen unless the upper thermostat is satisfied.

All is not lost. The element is a piece of cake to replace, especially on a new unit.

---Ed---

On a cold tank the upper element fires first to bring a first cycle of ready to use hot water, but from there on out it is the lower that does the majority of the work.


I would be changing the thermostats as well, as that heater was put in a situation of malfunction.


- - - - - -


Everything in Plumbing can be repaired or replaced.

When we don't take the time we need to take there is always something that pop's up and makes us take more time and fills us regert. It happens to all of us and I sure would hate to repeat those lessons.

You should take some plumbing repair classes when they cover electric water heaters, our tech school and local union offer them to all licensed plumbers for a fee and you should be able to get cont. education hours for taking the class.

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IF the upper element is not covered by water it will burn out almost immediately, assuming it is not a "SandHog" stainless steel element. IF that happens you will know it quickly because the meter's disc will not start spinning rapidly when you turn the power on to the heater, and you will not have any hot water no matter how long you wait.

The element is the only thing that gets damaged, and a dry fired element is very easy to identify.

What "electronics" does an electric water heater have? And why would they be damaged by dry firing the element. ALL the residue that might occur, and it is almost nonexistent, will be at the bottom of the heater and it will STAY THERE.

i dont think the repair guy has come yet to fix it...so the homeowner probably isnt happy..

some of the noises i heard sounded like it could be loose parts inside...is that possible?

if i buy a new element is it pretty self explanitory to replace it?

i may do it on Friday if they havent done it yet..

since the repair guy will probably have to charge the homeowner for the repair ill probably get a bad call..i already told her any issues just to pay it and ill reimburse her....it will make me look bad...

im deciding to admitt it when she calls or deny...either way ill pay.. im not worried about the $$

when i open up the panel what will i see? any tips on how to replace the parts?

If you have NEVER even looked into an electric water heater panel, this might be a bad time to do your first one, because the homeowner already thinks you are incompetent to have caused this problem in the first place.

what point of submersion are we talking?and any time an element burns it can take all the components energized with it .dry fire although it seems straight forward ,can result from a lessor level of water over the element that is required to make it cool enough to burn,allowing it to burn or heat the water a little but damaging the element .Since he said the water got warm not hot.I would see his problem as a tank filled above the element but only an inch or so resulting in a high amperage burn out.If his service person finds a spring coil hanging out of this new element I am correct.if it was truly dry fired the water would not have warmed at all and nothing but a nub or melting metal rod will be removed.A burnt out element is not a shorted out one and there is a difference.hopefully waulk will shed some light on what his tech finds.

she will not be home when i do it

ill look like the Hero because the Rheem guy came today and played w/ the switch on the wall and didnt even touch the heater...she's very angry at Rheem for sending an incompetent...they guy spent most of his time w/ her trying to sell her salt for her water softener.

from reading up on how to do it id say it seems very easy

turn power off
drain heater
disconnect leads
unbolt the element & replace

piece of cake....

its accessible, but barely...ill be reaching around stuff to work on it..i cant get directly in front of the element panel.


do i unbolt it w/ a socket wrench? or how does it unbolt?
anything i need to know about the electrical for it?

is their pieces inside the heater? how do i get them out?


will i ever do this again? NOOOOOO

thanks for the help!

For a first timer,Turn off the power,Turn off the water, drain about 20 gallons of water from the heater after you confirm the power is off with your tester. Make sure you have the new element with the gasket installed . Remove the 2 wires from the element, un screw the element with your 1 1/2 socket wrench and screw in the new one and reverse the process.

dont think i can mess that one up

what about the debris inside the heater?

yep turn power off/check it to be sure,always.bring a six sided 1 1/2"socket 1/2" drive and breaker bar work well.start draining the tank disconnect the wires at the element,bend them up out of the way.place a dry cloth at the panel opening bottom.unscrew the element counter clockwise.After the first half turn you may be able to remove it with your fingers.Make sure the rubber gasket comes with it.What you have now, effects what you look for next. if you have most of the element in your hand,reinstall the new one ,you will wish to stop when the screws are horizontal to one another on the new element.Allow for this as you feel it tighten against the tank.reconnect the wires at the element and check the other end of each wire at it contact screw to be sure it is still tight.If the old element is intact,it still makes a loop back and fourth.fill the heater up with water and purge all air.replace cover and flip the power back on.If part or all of the elements loop is missing,move to the lower element and remove as you did the upper.with a flash light and a grab tool remove the rest of the dry fired element.Reinstall lower element rewire and fill the tank purging all air ,power on.As a side note when installing the new elements keep them straight in line with the hole.inserting them at a side angle and then trying to straighten and tighten could pull the dip tub out of place.After fifteen minutes you should have warm water, hot in fourty five. This is assuming dry fire element and a omh test would be preformed before any element was removed.If you also did the wiring in a hurry could be you simple have one leg not working.

"ill look like the Hero because the Rheem guy came today and played w/ the switch on the wall and didnt even touch the heater"

Why was he playing with the switch on the wall? Are you sure you had 240 volts to the heater when you first connected it?

Bolt-in elements used to be fairly common, does anyone use them any longer or do all manufacturers now use screw-in elements?

thanks...i wont be able to get my head within 2-3' of the panel..ill be reaching around the heater...furnace is in the way...its jammed in a mech. closet...i have access for replacing the element, but cant get my body where it needs to be to see inside the panel...ill be doing it somewhat by feel.

if the element is broken off and i cant retrieve it does it float or sink?

If the element is immersed in water, regardless of how much, or how little, it will NOT burn out. If ANYTHING shields it from the water, such as mineral build up, NOTHING will stop it from burning out.

There is either NONE, or you cannot do anything about it if there is any.

quote; ..i cant get directly in front of the element panel.

WHO installs an electric heater without orienting it so you CAN get to the element access doors? You need an element socket wrench.

I have NEVER seen a 240v heater with a "switch on the wall". I can diagnose an electric water heater in less than 5 minutes and know what and where the problem is. Less than that to replace either element. Turn off the power, turn off the water, release the pressure, remove the element, insert the new one, and turn on the water, then the power. No need to drain ANY water if you know what you are doing and do it properly.

You need about 16" in front of the heater access panel to remove and insert the element. If you do not have that much, you are going to have to disconnect the heater and rotate it so you do. Why isn't the front of the heater facing whatever direction you used to slide the heater into the space? It should NOT be facing the furnace.



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when replacing waterheaters i install them the same way they were originally...i flat rate price them, so i cant sit there for an extra hour for free.....

i replaced the element today...no problems what-so ever...very simple...it fixed the problem

the element was 1/2 gone...2" stub on side and a 8" stub on the other.

i talked to my local service friend and he said it would be ok...it will just sit on the bottom.

and YES i was the Hero!...the homeowner was none the wiser...the Rheem repair guy couldnt fix it, but I could...yea i ate probably 2 hours(including travel time) and $30+ for the element...but my reputation is intact!....i bought the official Rheem 1 1/2" socket thingy

its a 6 family condo and every unit is nearing a water heater replacement...i gave the homeowner my cards and asked her to give them to her neighbors...ill be back



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$30 seems a little steep for an element, I think I used to give around $8 to $10 for them, but that was 25 or more years ago. If you do more water heater changes in the building, I hope you allow a little more time for them and turn them so you can later easily get to them for servicing.

"I have NEVER seen a 240v heater with a "switch on the wall".

I have, it's code if there is no circuit breaker within sight, but I have seen a lot more of them without a service disconnect.

That is the problem with flat rates, either you charge enough to cover the unusual ones, thus overcharging for the others, or charge for the normal ones and "eat" the ones that go over. BUT I NEVER do an installation which is going to make life difficult for me, or the customer, someday in the future.

I will stand by my statement that I have "NEVER" seen one. The closest we come to it is when the customer installs a timer and it has a manual "OFF" position, and those I test for power afterwards because they do not always wire them correctly.

Well hope you ran water on the hot side to each fixture .or you may be called back .HJ What is the white stuff between the core wire and the outer tube????Yes it can float.how much is loss in the heater will directly effect the amount that must pass through the fixture.And if the remaining exterior tube is leaning on the bottom element it will also be lost soon.Waulk .Glad you replaced the element, but sad to here you installed it in this manor.Keep a couple forty fives on the truck for rotation and make them call an electrician if it will not reach.

NEVER had a faucet get plugged up or ANYTHING from the "white stuff" in the element. And I have "cut off" many SandHog elements and left them in the bottom of the tank when they were too "distorted" to remove out of the opening.



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Never used a sand hog other than in the bottom.But never leave any thing in there when I can easily remove it.In Waulks case shame on him.

how should i get it out?

shame on me for being so stupid to flip the switch before it was full...i feel very dumb...lesson learned the hard way..

my service friend says he gets distorted elements once in a while and has to break them off inside the heater...he claims Rheem recommends doing it that way...he says no harm...

i dont see how the copper can float...i think im safe.

fingers crossed

i dont like to do a substandard job ever...its rare these things happen with me...2 days w/o a call back, so everything must be good!

The key phrase there is "easily remove it". Sandhog elements have a wavy shape, and after they have been in for a while the "U" shaped foldback becomes more of a "V" as it opens up and becomes impossible to remove through the opening. Especially if it opened enough to hit the bottom of the heater and wind itself up while unscrewing it.

Don't worry about it. I do the same thing the guy from Rheem does when the element is too distorted to come out. A small pair of bolt cutters does the job every time.

"I will stand by my statement that I have "NEVER" seen one. The closest we come to it is when the customer installs a timer and it has a manual "OFF" position, and those I test for power afterwards because they do not always wire them correctly."

I don't doubt you a bit, but it is still code (NEC). The best and simplest example I can think of is when the electric service and panel is in the garage and the water heater is in the basement, a service disconnect is required by code. The same would apply to an electric furnace which is why so many electric furnaces have circuit breakers installed in them at the factory to land the circuit within the furnace. The circuit breakers qualify as a service disconnect. A timer on a water heater does not qualify as a service disconnect by most inspection authorities. It all boils down to your AHJ and THEIR interpretation of the code.

Waulk make me fell better in a month ask if you can recheck the customers heater for field reference and test the lower element for continuity.You feel your on the hero list, this check weather they will or not confirms it it their mind and mine.

IF there is any problem, he will NOT have to call them to retest it, THEY will be calling him with a "lack of sufficient hot water" problem. But unless he did something else wrong, there is ABSOLUTELY nothing that has to be rechecked. I do not, and would NEVER, do it.