Hot water heater needs help

[burntmuch]

OK Ive got a electric water heater 80 gallons. About 5 years old. It trips the reset button on the water heater, then stops working. So I hit the reset button, Then it works great, like too good. Water is way too hot. That last for about a day then trips the reset button again. Is this bad heating elements or bad thermastat. Thanks in advance  Jay

[PowPow]

sounds like a bad thermostat.
bad heating elements would either not heat or trip the circuit breaker.

[mechanic]

You've no doubt got two thermostats.  Which one is tripping?  I'm assuming the reset is on the thermal unit.  Just replace it with a like one and you should be fine.
 
Ben

[burntmuch]

Thanks guys.Im gonna replace the thermastat. tomarrow morning.

[mcwoodduck]

Being a boiler expert...
I would look at the two setting.  One with the reset is a safety.  The other is your operating control.  Sounds like the safety is working.  Sounds like the operating control has gone wonkey.  Also how hard is your water?  The setament gets pulled out by the heat and acts as an insulator.  The heating element may over heat and heat up the calcuim that over heats the water.  Also the water temp coming in can raise your stored water temp.  how hot is your cold water?  I know you asked what time is it and I am telling how the watch works.
 
 

[PowPow]

I saw where some electric water heaters have two elements with one thermostat and one manual reset high limit on each element.


If you have one element, should be easy to figure out.
If you have two, use a multimeter to figure out which one stays closed when you run it up and down.


(Be careful, turn off the power first, your mileage may vary, member FDIC)

[burntmuch]

I ll know more tomarrow morning, at work right now till 8 am.
 
mcwoodduck, its good to know how a watch works when your trying to fix it.  Thanks  Jay

[mcwoodduck]

My phone number   Let me know what model you have so I can pull out a wiring diagram and help you if needed.  Anyone that has a boiler or commercial water heater and needs help can call.
Please remember I live on the west coast.   please do not call at 4am my time unless something is very wrong.

[burntmuch]

OK I do have two thermastats one for each heating element upper & lower. How can I tell which one is bad. The safty is on the upper.
mcwoodduck  its a Bradford white 80 gal Model # MI80R6DS13.
 
The upper is $13 & the lwer is $8. So not a big deal if I just replace both. Still cheaper than having someone come out & fix it. Funny thin is I ve got class tonight then 24 hour shift at the fire station. tomarrow morning. The wife & kids may just have to jump in the pool for a bath. Im not gonna be able to get to his till Friday morning.

[SHOOTALL]

 
 Why would this condition exist ? because when you first fill the tank the upper element comes on and heats the water in the top of the tank. Then the lower comes on and heats the water in the lower part of the tank. As hot water is used cold water comes into the bottom of the tank and the lower element comes back on . Hot water rises so the top gets hot from both flow upward and heat rising when water is not flowing . So you reset the heater after the upper part has cooled and the upper element comes on and when it satsyfieds the lower comes on and trips the safety.
 there is a chance of a bad T-STAT also. Plumber advice change both T-stats and elements and be done with it.

[PowPow]

The way to tell which one is bad:
Disconnect power to the heater
Dial each thermostat up all that way and then down all the way a few times.
Should be a "click" somewhere in the middle where it crosses the switch point at the current temp.
The bad one won't click because it is stuck closed.


If both or neither click and you don't have an ohmmeter to check continuity, replace them both like Shootall says.
Gas to the supply house and your off-time is worth something.
Could be like car headlights, if one breaks the other might last another week.

[SHOOTALL]

elements read 11-13 on your meter are good