Questions and answers on testing and fixing an electric water heater reset switch or temperature limit control.

This article series describes how and why to test the high temperature cutoff switch and how to use the hidden reset switch on electric water heaters.

How To Test High Temperature Cutoff Switch Located at the Upper Heating Element

These heater temperature high temperature cutoff control questions & answers were posted originally at ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST - be sure to review that article.

Watch out: removing access covers on an electric water heater exposes live voltage-wires: touching them can cause injury, shock, or death.

On 2018-11-14 by (mod) - temperature control is getting power but water heater is not hot

First try re-setting the control.

If the temperature limit control is receiving power but can not be re-set even after waiting for the water heater to cool down (that is to say and the water heater is cool) then I suspect the control is defective and needs to be replaced.

On 2018-11-14 by Mandie

@Steve,
Mines doing the same did you figure out what was wrong with yours?

On 2018-11-14 by Mandie

My electric water heater acts like it's not getting power but I know it is because I can touch the wires of a light to it and itll light up...I'm poor and that's the only way I can test to see if its getting power.

Still not heating and it has new elements. Reset button makes no noise when pushed either. Any suggestions what could be wrong?

On 2018-10-28 15:45:54.022299 by (mod) -

Helpful comment, K.
Thank you.

On 2018-10-28 by Kidsprocket -use an Amprobe to check for abnormal current draw under load

@Chad,
Your hot water heater may be somewhat functional, yet pulling too many amps under a load.

This could be due to a burnt, pinched or broken wire, burned, corroded, or carbon covered contacts in the high temp kick outs, or a corroded, burnt and failing heating element.

An amp probe should point the way to your problem.

On 2018-06-22 by (mod) - I can not find the water heater switch in the circuit breaker to cut it off.

Sonja

Most electric water heaters are 220/240VAC - so in the electrical panel you should see a two-pole circuit breaker whose toggles are tied together such that both switch on and off at once.

My photo (of an electrical sub-panel) attached below shows two-pole circuit breakers (red arrows) and one single-pole circuit breaker (yellow arrow).

Switch off two-pole breakers in your panel if your water heater is indeed a 220V unit and power should be successfully turned off.

Watch out: do not try doing your own electrical work if you are not trained to do so. Making a mistake can cause a fire or death.

PS

If you send me photos of your water heater and of your panel I can comment further. Use the Add Image button to add a photo to a comment.

On 2018-06-22 by Sonja Floyd

The main switch for the Rheem Hot Water Heater is not marked right. I had it of 2 days and still had Hot Water.

I need to get the heater out of the wall and replace the floor it sits on. Then the heater for corrosion.

May have to replace it. When the heater fell forward, it poked not only a hole in the wall but also it hit a piece of wood and knocked off something that caused a leak. The floor rotted out.

The problem is that I can not find the switch in the circuit breaker to cut it off. I don't have the money to pay for this. Please help and instruct me to find the cut off switch in the circuit breaker. Thank you.

On 2018-06-10 10:41:41.823805 by (mod) -

See the water heater element tests at

https://inspectapedia.com/plumbing/Electric_Water_Heater_Repair.php

On 2018-06-10 10:09:45.918707 by Joe

I have a water heater that is getting power to the thermostat, heating elements , but is still no hot water. Any help will be great. Thanks

On 2018-01-14 01:57:41.652758 by (mod) -

Jackie

There are several "doesn't go click" reset button situations:

1. the reset button just tripped off in response to an over-temperature condition and the safety device needs more time to cool down before it can be re-set. Try waiting 15 minutes or longer.
This is most-likely

2. the reset button has not tripped and so does not need to be re-set; the problem is elsewhere
This happens

3. the reset button or control is defective and needs replacement
This is less likely but possible

4. There is no electrical power to the heater

5. There is some other problem neither of us has considered

On 2018-01-11 23:28:28.479071 by Jackie

If I push the reset button and it's just loose and doesn't go click, then what?

On 2017-08-23 08:45:33.359159 by jay

hello, I am designing a hot water clarifier. how to calculate the KW of the Electric BAck Up hEater?
What is the formula?

On 2017-06-28 17:10:31.711149 by Steve

I had a circuit breaker trip that was also connected to the hot water heater after I reset the breaker there is no hot water and it seems like when I press the reset button it doesn't click rounding it just pushes in any idea what's wrong

On 2017-06-13 21:07:30.294889 by (mod) -

Chad

To me this sounds like there is a wiring error - someone is overloading a circuit by running too many things on it: central air, water heater, lights.

OR there is an underlying problem with the building's neutral or ground wiring.

Leave OFF everything that is acting oddly, to reduce the chance of a fire or death by shock. and call an electrician to trace the circuits to see what was cross-connected.

Keep me posted.

On 2017-06-13 17:36:27.664259 by Chad

I was working on my central air unit and came back in the house and the bedroom and bathroom lights were off and my hot water heaters not heating. I replaced the breaker and the bedroom and bathroom lights work but not the hot water heater. Every time I push the reset switch on my hot water heater the lights go dim Why? Can someone please help me out with some advice

On 2017-05-19 01:19:25.253759 by (mod) -

Stacey, you're probably referring to the electric water heater thermosat: I'd say no, though often it's least-costly to buy a water heater repair kit that includes those parts.

On 2017-05-18 21:40:05.574279 by Stacey

When I change elements do I have to change those electrical coponents also

On 2017-04-19 20:42:45.133537 by (mod) -

Sorry Mike I don't understand

On 2017-04-18 19:59:00.935011 by mike

element tests with a dim light

On 2017-02-20 15:32:48.468702 by (mod) -

Russ

The reset button shown at the top of this page is behind the cover on an electric water heater.

I don't know about your instant water heater: we'd need the brand and model so as to find its instruction and control manual.

On 2017-02-19 23:07:14.666622 by Russ

To set the reset button do I need to take the cover off my instant water heater

On 2017-02-18 23:24:09.260391 by (mod) -

Start by testing to see if the element has failed - a likely event if all air was not purged from the water heater tank

On 2017-02-16 14:56:28.977317 by Terrence

I have replaced the upper element on my hot water heater. It worked for about 5 hours then the diagnosis reader indicated that the upper element was bad again. The water was hot until this happened then I got no hot water again. I hit the reset button it heated up but later I got the same problem. Why is this happening?

On 2017-02-18 by (mod) - water heater upper element failed after it was replaced

Start by testing to see if the element has failed - a likely event if all air was not purged from the water heater tank.

See ELECTRIC WATER HEATER ELEMENT TESTS

On 2017-02-16 by Terrence

I have replaced the upper element on my hot water heater. It worked for about 5 hours then the diagnosis reader indicated that the upper element was bad again.

The water was hot until this happened then I got no hot water again. I hit the reset button it heated up but later I got the same problem. Why is this happening?

On 2017-02-18 by (mod) - water heater red button popped - won't reset

Morgan:

The red button on the high temperature limit on the water heater pops if the heater temperature is unsafe - too high.

You must wait for the water heater to cool down before you can try re-setting the button.

Wait an hour or so then press the button in until it clicks.

If the button won't stay re-set then the control has failed and needs replacement.

On 2017-01-24 by MORGAN

The red botom is popped i thinkas i can not push it and hard, but the heather still working?

On 2017-01-16 by (mod) - check power to the water heater

Jerry,

If the water heater is not getting power, then none of the components that have been replaced are likely to be at fault. Start at the electrical panel.

Is the power to the water heater turned on. You may need an electrician to avoid risk of being killed by electric shock, but a professional would use a meter at the electrical panel to confirm that the circuit breaker when switched on is actually delivering power to the circuit.

Once me know that the wires are alive leaving the breaker we check at the other end of the circuit at the water heater.

If there's no power there than you have an open wire in the circuit. If there's power where the circuit enters the water heater, then you've made a wiring error. Watch out there is danger of electrocution fooling with these wires, as well as fire.

On 2017-01-15 by Jerry

I replaced both heating elements, both thermostats (top and bottom) and installed a new 20amp 220 breaker in the house panel box.

the water heater is not getting power. does not heat.

also, the red reset button does not pop out, which was the original problem, that thermostat button never popped out as the cause of failure.

what to do to start heating

On 2017-01-13 by (mod) - check electrical connections for corrosion or looseness

George,

I'm speculating beyond my competence but I'd start by looking for a loose or corroded wire or connection.

If that doesn't bear fruit I'd replace some parts - they're very inexpensive and pretty easy to do: heating elements and thermostat are sold as a package by plumbing suppliers and building suppliers for about $40. U.S. - that's a fraction of what you'd spend hiring a diagnostician.

Watch out: be sure all power to the heater is OFF or you could be killed just touching any electrical connector

On 2017-01-13 by George

Every other week my ECO trips on my electric water heater; easy to reset. I tested the upper and lower elements at 12.8 ohms on 4500 watt elements

. ResistNce from all leads to the water tank was infinite, no short.

Turned power on to cold tank; upper element powered up, then thermostat shut down; lower element powered up then shut down by thermostat. How can I analyze further this intermittent problem?

On 2016-12-27 00:56:43.682076 by (mod)

Sounds unsafe, Alice. I think perhaps your water heater thermostat has failed. It's time to call for repair.

On 2016-12-27 00:22:42.983863 by Alice

I have a hot water heater only about 7 years old. Recently I have noticed that the Hot Water is Scalding hot.

I had the temperature lowered when it was installed but now the temperature seems to have Changed by itself. Single handle faucet and if I so much as get near center the water is scalding hot.

Can you give me a clue as to what it wrong and what I need to do? I now how to change the T-stats myself but I am not sure that is the problem.

On 2016-10-19 12:29:42.257475 by Kenny

Can anyone tell me what needs replacing to clear this code?

On 2016-10-19 11:46:45.357485 by Kenny

I am getting an e02(water temp exceeded high limit), it resets and comes back, all the elements are good, voltages are good. The water is not excessively hot.

On 2016-08-01 21:50:58.602772 by (mod)

Yes

On 2016-06-08 00:14:13.847963 by Anonymous

I have power to both elements at the same time is this normal?

On 2016-03-21 13:01:55.569992 by (mod)

Ken

Luckily electric water heaters don't have too many parts so we can usually debug these problems. You replaced the elements, but the trouble could be with the high limit sensor control itself. I'd replace the limit control / reset switch, and when installing the new one, be sure that its temperature sensor is in good contact with a cleaned surface. If the manufacturer recommends use of a thermally-conductive paste or grease be sure to include that too. Keep me posted.

Daniel

On 2016-03-21 11:14:55.928542 by ken

Occasionally the water temperature from my electronic water heater becomes scalding hot. Then is usually trips the reset switch. I have replaced both elements but the problem persists. Any ideas.

On 2016-03-14 13:40:57.014830 by (mod)

Changing the relief valve should itself have not one iota of impact on water pressure.

However if the plumber had to turn off water valves and perhaps drain some water from the water heater during the repair, the problem may be at the valve that was adjusted; it may not be fully open, or it may be damaged such that it will not open fully even when the handle is turned.

On 2016-03-14 13:29:05.893781 by Stephanie,grisham

Just had the pressure relief valve on my electric hot water heater replaced. Now, the water pressure is very low when hot water is,turned on. What would cause this & how can I fix it?

...

...

Continue reading at ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Electric Water Heater Articles

• ELECTRIC WATER HEATERS - home
• ELECTRIC SHOWER HEATERS
• ELECTRIC WATER HEATER CONTROLS


• ELECTRIC WATER HEATER REPAIR GUIDE
  • ELECTRIC HOT WATER TEMPERATURE CONTROL
  • ELECTRIC WATER HEATER ELEMENT TESTS
  • ELECTRIC WATER HEATER ELEMENT REPLACEMENT
  • ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST
  • ELECTRIC WATER HEATER RESET SWITCH
  • ELECTRIC WATER HEATER THERMOSTATS
  • ELECTRIC WATER HEATER - NO HOT WATER
  • RELIEF VALVE LEAKS


• ELECTRIC WATER HEATER INSPECTION CHECKLIST
• ELECTRIC WATER HEATER PARTS ID


• ELECTRIC WATER HEATER REPLACEMENT


• TIMERS for ELECTRIC WATER HEATERS


• WATER HEATER ANODE & DIP TUBE CHECK
• WATER HEATERS for HOME HEATING USE?

Suggested citation for this web page

ELECTRIC WATER HEATER HIGH TEMP CUTOFF TEST FAQs at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

Or see this

INDEX to RELATED ARTICLES: ARTICLE INDEX to WATER HEATERS

Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia

Ask a Question or Search InspectApedia

Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Apologies for the delay.

Only one image can be added per comment but you can post as many comments, and therefore images, as you like.
You will not receive a notification when a response to your question has been posted.
Please bookmark this page to make it easy for you to check back for our response.
Our Comment Box is provided by Countable Web Productions countable.ca

Citations & References

In addition to any citations in the article above, a full list is available on request.

---

ADVERTISEMENT

---