Electric Water Heater Diagnosis & Repair FAQs

More Diagnostic Questions & Answers on How to diagnose & fix an electric water heater

Electric Water Heater Temperature Too Low FAQs

Why is our water heater temperature just warm, not hot?

Temperature fluxuates from hot to just warm what could be the probem On 2015-02-02 by rick

Rick

If the water starts out plenty hot then runs tepid quickly the lower electric water heater element is probably burnt out;

If all of the hot water coming out of your water heater is tepid (not hot) then the upper heating element may be burnt out.

Or one or both electric water heater (geyser, calorifier, cylinder - various names for the same thing) thermostatic controls could be defective.

If you have about as much very hot water in volume on your water heater's data tag (like 30 gallons) that's about as much as you'll get at once from an electric water heater; electric water heaters are the slowest to recover.

You can regulate the temperature by installing an anti scald valvce - see ANTI SCALD VALVES & TEMPERATURE CONTROL / MIXING VALVES 

 

Electric Water Heater Output Water not Hot enough in cold weather

During hot weather (30 degrees Celsius) the water from my hot water cylinder is very hot - but in winter (-4 Celsius)I need to turn the tap nearly to full to get a warm shower (June 7, 2016) Jason said:

Reply:

Find and insulate un-insulated hot water piping; that may help.

Still if the incoming water temperature in winter is significantly lower than during hot weather, you may indeed have to set the heater's temperature up; that's because the incoming water is so cold that it cools down the reservoir of hot water in the heater more quickly.

Electric water heater only lukewarm after I replaced a heating element

I replaced heating element, thermostat & TP Valve. Water only gets lukewarm? 19 gal tank On 2019-12-07 by Duane proctor

by (mod) - upper water heater element is not working

Duane

Is this a heater with two heating elements - an upper and a lower?

If so the usual cause of just tepid warm water is that the lower element is working but the upper one is not.

If the water heater (calorifier, geyser, cylinder, or other synonyms - for other readers) uses only one heating element then it's possible that the thermostat is either not properly-set or is itself defective.

Let me know if these checks help you out. (This article series also includes procedures for testing water heater elements)

Watch out: if you're not familiar with safe electrical wiring you could be shocked or killed or could start a fire.

by gary moore

If it sets overnight the water cools down, then if you use the cool water it will heat up. Replaced upper thermostat , it is a 70 gal Rheem, has two heating elements

by (mod) -

That sounds as if the temperature sensor and upper heating element or their control is not working. Or you made a wiring error.

Electric Water Heater Plumbing FAQs

Why does hot water come out of our cold water spigot?

Can a defective hot water heater make the cold water faucet hot? 27 April 2015 Nick

Reply:

Nick,

"a defective hot water heater" is a bit of a broad term for me to give a narrow yes or now answer to your question. IN general terms, a water heater won't suddenly make cold water supply turn hot.

There are circumstances in which hot water may come out of a cold supply faucet even though the pipes are properly connected (hot to hot supply, cold to cold supply). Those include

1. Routing of cold water piping close to hot water piping, or close to another heat source (boiler room ceiling for example) combined with a period of dis-use of the water system can cause water resting in the cold water piping to become warm.

This situation is easily diagnosed by observing that water comes out of the cold water tap warm or even hot but as more cold water is run the water becomes and remains cool or cold.

2. By convection, in some building piping systems hot water can rise out of the hot water tank into cold water piping and even upwards in building cold water piping to the fixtures. This is most often due to the loss of all or part of the dip tube in the water heater

The dip tube both delivers incoming cold water (in the water heater tank) to the bottom of the tank and it also prevents hot water (from the top of the tank) from rising by convection into the building piping.

Electric Water Heater Won't Turn On

No electrical power after we replaced our electric water heater

Replaced the hot water tank, a brand new one from Lowes, and getting power at top but nowhere else. No power in thermostat or either elements On 2021-02-05 by Chris

by (mod) -

Chris

Did you turn the electrical power to the heater on for even an instant before it was filled with water and all are purchased? I'm sorry to say that if you did the elements probably burned up.

New electric water heater does not draw electrcial current

Brand new electric water heater is not drawing any power. Our meter is barely spinning. What could the problem be? On 2020-08-08 by Yoshi

by (mod) -

Yoshi:

Watch out: if you are not familar with safe proper electrical wiring don't touch any wiring or connections as you could be shocked or killed.

You can, however be sure that the circuit breaker for your electric water heater is ON: try switching it all the way to OFF, waiting a moment, then switching it all the way to ON.

Your electrician will use a multimeter or voltmeter (DMM or VOM) to confirm that power is being delivered to the water heater, and if it's not, then there is a loose or disconnected wire in the circuit or the breaker or fuse is defective.

If electrical power is being delivered at the electric water heater's terminals but the heater never turns on, the heater could be improperly-wired or it could have a defective thermostatic control or even bad heating elements.

That can happen, even to a brand new water heater if you turned on electrical power to the heater before it was absolutely full of water and after making sure there was no air in the hot water system.

Watch out:turning on electrical power to an electric water heater if the heater's elements are not under-water, that is if there is air in the water heater cylinder or tank will usually result in an immediate burn-up and desctruction of the water heater elements.

AO Smith Electric water heater trips circuit breaker

AO SMITH 40 gal shorty is flipping 30 amp breaker in panel box. Haven't inspected it. Will let me reset and after a few minutes it will trip breaker again. Water does heat after reset before tripping again. Ive put in several new water heaters, and repaired several. None of them acted like this. On 2020-05-24 by Glenn

by (mod) -

That sounds to me like a corroded heating element that is shorting out or another wiring error that's shorting to ground or to neutral.

Must Refill Electric Water Heater Before Power-On FAQs

Tip: See ELECTRIC WATER HEATER - NO HOT WATER

No water comes out at faucets after draining the electric water heater

I turned off my water heater and drained it. I have not water coming out of the faucets but I haven't turned the water heater back on yet? On 2020-01-27 by Bill

by (mod) - how to re-fill an electric water heater before turning it back on after service or repair

Watch out: Never turn electrical power back on to an electric water heater before you have refilled the water heater tank and confirmed that there is no air in the tank by opening and getting water flow at the hot faucets. Otherwise you risk immediate burn-up of the water heater elements.

Open neaby hot water taps, then open the cold-in valve and the hot-out valve at your electric water heater.

In refilling the water heater you may need to open the relief valve to speed getting air out of the tank but it shouldn't be necessary.

With the hot water tap or taps open at plumbing fixtures near the water heater (upstairs or above it is best), once you've got steady water flow at the hot water tap - no more bursts of air - then you can close the taps and turn on power to the heater.

Installed new electric water heater - still no hot water

Have new hot water heater and breaker and still no hot water can u help On 2020-07-06 by Heather

by (mod) - did you turn on power before filling the water heater tank?

Heather

Watch out: If the heater was turned on before it was filled with water than might burn out the heating elements. Did that happen?

See more-detailed diagnostic steps at

ELECTRIC WATER HEATER - NO HOT WATER

Other Electric Water Heater Electrical Problems FAQs

Arcing electrical spark sound from electric water heater

Every once in awhile I hear a arcing sound from my hot water heater im concerned the water heater is new and so are the electrical wires from the service box to the heater On 2020-02-03 by Denise

by (mod) -

Denise

If that's really an electrical wire arcing noise then the wiring or heater is unsafe, should be shut down, inspected, and repaired. Electrical arcing sounds like a loose connection or improper wiring that could be a fire or shock risk.

Electric water heater thermostat control screw looks dark - sign of overheating?

My unit doesn't need reset and no breaker problem. Only thing is lower thermostat control screw looks oxidized. What do you think? On 2019-12-31 by John

by (mod) - Discolored electrical connector at water heater thermostat may indicate overheating

that could be a sign of an overheating or bag or arcing electrical connection

Electric Water Diagnostic & Error Code FAQs

1 long beep (approx 30 seconds) from my junction box on my Whirlpool hot water tank

Periodically I get 1 long beep (approx 30 seconds) from my junction box on my Whirlpool hot water tank (electric), then it shuts off and I might not hear it for days or weeks. I have checked for water leaks, and the heating elements have recently been replaced.

I don't see anything in the book, or online about this issue, and wonder if someone might know. Thank you. On 2019-11-17 by Sandy -

Reply by (mod) - Whirlpool Electric Water Heater Diagnostic Codes & LED Flashes

Sandy and Melissa

To get to a more-reliable diagnosis and comment we need the specific Whirlpool electric water heater model number (post a photo of the data tag if you can).

Here is bit of typical diagnostic information from a Whirlpool "Energy Smart" electric water heater

Whirlpool Water Heater Diagnostic LED Light Codes

The Green/Red LED light indicates the status of the electronic thermostat (See Figure 10A).

• Green LED will signal normal operation. The green LED will blink 2 times per second to indicate that power is applied to the upper heating element and at a faster rate (4 times per second) to indicate that the lower heating element is powered.

• Red LED will fl ash error codes. If a fault is detected by the electronic thermostat, the LED light indicator will use the red LED to indicate the fault detected.

The flash code sequence is to consist of 1/2 second flashes of the red LED each separated by a 1/2 second off period.

The number of fl ashes indicates the fault code number.

(See diagnostic code chart section in this manual).

After the last 1/2 second “on” period, the LED will remain off until a total of 5 seconds has elapsed for the fault indication cycle (there is a 5 seconds delay before the fault
flash pattern repeats). After the 5 seconds are completed, the fault indication cycle is repeated starting with the first 1/2 second-fl ash. The fl ash sequence will be repeated as long as the fault remains.

Only one fault can be declared at a time. NOTE: the green LED is turned off when a fault code is being displayed, even though the heater may be operating in limp mode with an element on. See diagnostic code chart section in this manual.

an EXCERPT from that table is given here

Source:

• Whirlpool ENERGY SMART WATER HEATER MANUAL [PDF] retrived 2019/11/19 original source: http://www.whirlpoolwaterheaters.com/media/123507/318686.pdf
  

Where to get water heater repair or installation manuals

For other readers,

at WATER HEATER MANUALS - home

you will also find heater manuals by name such as

WHIRLPOOL WATER HEATERS

- also see AMERICAN WATER HEATER

as that company produces some heaters sold under the Whirlpool brand

Followup by Sandy: Periodic Whirlpool heater buzzing, coninued

Hi, this is Sandy, again. My Whirlpool model # is ee2h40rd045v, serial # 0239130503, a 2002 unit.

There are no flashing lights at all. There are no ongoing beeps as in a water leak. This is just a periodic buzz which shuts off with the reset button, or by itself in about 30 seconds--from the junction box. I thought maybe the box needed replaced. thank you so much! Sandy

by (mod) - if the buzzing is electrical, not an alarm, it's a fire and shock hazard

Watch out: if the buzzing sound is NOT an alarm sound but rather is coming from a wiring or electrical component then we must worry first about possible safety concerns. Sometimes a buzzing noise at an electrical appliance including a water heater can be a loose parking or overheating connection. The safe thing would be to turn that equipment off to avoid a fire or shock.

Often a visual inspection of the controls and connections will turn up the culprit. It can also help to listen very carefully to pinpoint the source of buzzing.

To keep us posted as I'm concerned for your safety and because what you find will help other readers

Air in Hot Water Supply FAQs

White water after installing a new water heater

With a newly installed electric water heater, is it normal for my water to have an white appearance? (Mar 12, 2016) Wanda Loadholt said:

Reply:

Run some water into a tall clear glass and watch it. If the white disappears you may be seeing very fine air bubbles - a condition that should stop on its own.

Watch out: there are other air bubbles or air discharge problems at hot water faucets that are more-serious or possibly even unsafe, as we explain

at AIR DISCHARGE from HOT WATER 

Electric Water Heater Element Failure FAQs

Single-element water heater not working

My hot water heater only has one heating element I have replaced the element and the temp control box and still l don't have hot water (May 16, 2016) John jones said:

Reply:

Check that there is actually electrical power to the components.

Test that the new heating element is good.

Check that the thermostat has not tripped.

Bottom water heater elements keep corroding rapdily

We bought a house two years ago. All electrics replaced about two years before that. Hot water is heated electrically. Was OK for first 18 months after we bought house but suddenly bottom elements in hot tank have been corroding and shorting electrics.

They only last five or six weeks - latest one fitted on 13 May and went today! They have been fitted by different plumbers, with good reputations. What is likely cause and cure please? Thanks! 2016/06/18 David Kettleburgh

Reply:

I don't know, David, but I would check for

- a bad sacrificial anode in the water heater

- errors in electrical wiring, shorts, stray currents

- wrong heater element wattage being installed

- defective heater thermostat that's not shutting off the heating elements

- corrosivity index of the water supply

OK to disconnect lower heating element?

Can I disconnect wires on Lower heating element has an overnight repair to prevent breaker from tripping? (Apr 18, 2016) Ozcar said:

Reply:

Yes Ozcar,

with this warning:

Watch out: the short circuit that is causing the element to trip could be in wiring, a control, or at the heating element itself.

With power off to the heater, disconnect the wires and cap them off and

WATCH OUT as someone touching live wires is likely to cause a bad shock or death. Eliminating the lower heating element will mean that you will have less total hot water quantity.

Kenmore electric water heater element not working

I have a kenmore double element water heater that is not working correctly. the bottom element comes on and seems to work fine, however the top element never get power to it for some reason. In my rational it appears to be a thermostat but which one. Is it the one at the bottom element or is it the one at the top element. Has anyone had this problem. On 2014-03-03 by Ralph

by (mod) -

Ralph, not all heaters are wired the same so you'll want to check the manual for yours. but it's common for just one of the 2 elements to burn out. Or a top thermostat control controlling the top element could be bad.

How to Tell if my Electric Water Heater Switches on Both Elements When it Should

My heater is the non-simultaneous type so suppose I need to stay with the testing a little longer to see if it is switching from the bottom to top and go from there. On 2014-03-05 by Ralph

by (mod) -

Sounds right Ralph; basically the number of components to test is pretty limited: thermostats and heating elements and wiring, so you should be able to figure it out.

Sometimes just exposing the components by opening the access cover will show something obvious like a burned component. If I don't see that, usually the next thing I check (because it's so easy) is the individual heating elements (with power off and wires disconnected).

keep me posted, what you learn will help others.

by Ralph

Thanks for responding DanJoe, I checked the element and it tested good with a meter. didn't know if the botton thermostat had to be satisfied before the top element got power or not. Thought maybe both elements came on at the same time but don't know.

by (mod) -

A.O. Smith (water heaters) has an excellent service handbook that explains these operating modes and instead of flip-flop they call it "non-simultaneous operation" of the electric water heater elements.

It is possible to convert some flipflop electric water heaters to operate the two elements simultaneously but as AOS points out you can't do that if the total amperage draw exceeds the circuit and equipment rating (say 40A).

Yeah I don't know either - it depends on the heater. Quite a few of them run one first and then the second as needed. Most are what we call "flip flop" electric water heater systems.

When the tank is full of all cold water, the upper thermostat flips on, heats up the water in the upper portion of the heater.

That's also where hot water exits to the building - from the top of the tank at the hot connection.

Once the temperature set on the upper heater's thermostat has been reached, the
thermostat control will then flip power down to the lower thermostat that controls the lower heating element.

The lower thermostat switch will turns on the lower heating element and that in turn heats water in the bottom of the
water heater until that water reaches the temperature setting on the lower thermostat.

Now the whole water heater is "hot". Of course life is more complicated. When the water heater is in use cold water is entering at the tank bottom (out of the end of the dip tube) but also somewhat mixing up water in the tank. If the upper tank is still hot, cold water entering in the tank bottom will contact the lower element and thermostat and those will turn back on.