Water heater reset button

[electriciangirl]

I was called to look at a water heater that has an intermittent problem with the reset button on the unit tripping. All replaceable parts on the water heater have been replaced, elements and thermostats. The breaker at the breaker panel has never tripped. I was not able to find any shorts or wiring problems. Would a build up of excess heat in the access area where the reset button is located cause this to happen? It seems to happen when they are using a lot of hot water.

 

[Little Bill]

I was called to look at a water heater that has an intermittent problem with the reset button on the unit tripping. All replaceable parts on the water heater have been replaced, elements and thermostats. The breaker at the breaker panel has never tripped. I was not able to find any shorts or wiring problems. Would a build up of excess heat in the access area where the reset button is located cause this to happen? It seems to happen when they are using a lot of hot water.

Is there adequate insulation around the thermostat and element connections?

 

[jumper]

Here is a link to quick guide on the subject.

http://www.water-heater-repair-guide.com/waterheaterresetbutton.html

 

[electriciangirl]

Is there adequate insulation around the thermostat and element connections?

This is what I was starting to think about, as all parts have been replaced, including the elements, thermostats, and limit switch. All new parts and everything seems to check out okay, but that reset button still trips.

 

[weressl]

This is what I was starting to think about, as all parts have been replaced, including the elements, thermostats, and limit switch. All new parts and everything seems to check out okay, but that reset button still trips.

I believe that the reset is actually part of the secondary(safety) thermostat - not the main, regulating one - and itself could be faulty. Actually overinsulation could be the cause of overheating and the overtemperature protector is 'seeing' more heat than there actually is. (Similar phenomena ot what is expereinced with overload elements if they are located in an overehated enclosure: premature tripping, way before the overcurrent state reached.)

 

[electriciangirl]

I believe that the reset is actually part of the secondary(safety) thermostat - not the main, regulating one - and itself could be faulty. Actually overinsulation could be the cause of overheating and the overtemperature protector is 'seeing' more heat than there actually is. (Similar phenomena ot what is expereinced with overload elements if they are located in an overehated enclosure: premature tripping, way before the overcurrent state reached.)

ALL replaceable parts have been replaced. So a faulty reset button or secondary thermostat is unlikely, unless they were replaced with parts that were faulty right out of the box. Perhaps the over/underinsulation might be the problem?

 

[__dan]

The new replacement parts could definitely be bad, bad calibration. The manual reset is a high temp limit. So what is the water temperature? If the operating control, thermostat, is set and working correctly and water temp is good, replace the high limit again. If the operating control is not working and water temp is too high, the high limit trip is good and reset or replace the operating control again.

Every water heater I have seen has the controls buried right in the insulating blanket. The controls use a contact thermal snap disc on the tank.

 

[hillbilly1]

ALL replaceable parts have been replaced. So a faulty reset button or secondary thermostat is unlikely, unless they were replaced with parts that were faulty right out of the box. Perhaps the over/underinsulation might be the problem?

I don't think it is an insulation problem, even though the elements have been changed, I would lean torwards another defective element, could have been damaged during installation, or if power was turned on prematurely. If it has a current leakage to ground, it can continue to heat eventually tripping the high limit. I would check the continuity with them disconnected. They should read fairly close to each other, terminal to terminal, and terminal to ground.

 

[hillbilly1]

By the way, an easy test would be using an ammeter to check for current once both thermostats are satisfied.

 

[Dennis Alwon]

Generally speaking the reset trips when a thermostat is not functioning properly. So my guess is you have a bad part or the temp. is turned up too high on the tank. Try turning the t-stat down a bit and see what happens.

The reset button measure temperature and, I believe, it will not trip on fault current or overload.

 

[readydave8]

I have fixed this problem many times by finding a small leak, often where the pipes connect on top of water heater. Just a little bit of water will cool the t/stat, makes it try to heat water thats already hot, water gets too hot and kicks reset. On some I never saw water but saw rust streak.

And then there's been a few where this did not seem to be the case so I changed all working parts. And a couple of those did the same thing it had been doing. So my usual solution may not apply to your problem.

 

[readydave8]

Another situation that I have seen, especially if t/stat has previously been replaced:

Tstat must be tight against tank for it to work properly, if it doesn't fit springy steel things properly or otherwise is not tight against tank, water will overheat and (hopefully) kick reset.

 

[Little Bill]

To the OP: How old is the water heater? If it is 2+ years old it could have scale build up in the tank, especially if there is a hard water condition and that can cause problems with heating. Has the pressure relief (pop off) valve ever opened up?

 

[readydave8]

To the OP: How old is the water heater? If it is 2+ years old it could have scale build up in the tank, especially if there is a hard water condition and that can cause problems with heating. Has the pressure relief (pop off) valve ever opened up?

Is there a way to check for scale build up? Is there a way to get rid of it?

 

[Little Bill]

Is there a way to check for scale build up? Is there a way to get rid of it?

According to mfg. instructions (at least some of the mfg) you should drain the tank periodically. I think they say once a year, it's been a while since I read one. That would reduce the amount that has built up providing it was small enough to flow out when draining. If it has built up over time there probably isn't much you could do short of adding some chemicals like you would put in a boiler, let it sit for a while then drain. I've not heard of anyone adding chemicals but the concept would be similar. Of course if it's very old and was full of scale I would just "jack it up and slide a new one in under it.":lol: