# control on electric water heater burnt up



## Rio (Oct 13, 2009)

So we have an all electric rental home and the tenant called, said 'there's a really funky smell coming from the garage, smells like burnt brake linings or a clutch coming from the water heater........ what should I do?' 

He was told to turn off the breaker to the water heater and I'd check it out. I got up there and the burnt wire smell was pungent, pulled the covers to the electrical controls and hookup and sure enough, the component had one of the leads charred, so bad that part of the plastic housing was starting to melt.

i wasn't about to start trying to troubleshoot an old electric water heater, especially as I really know nothing about the controls on them so replaced the whole water heater and everything seems to be working fine but I'm curious and a little concerned and was wondering if some of the more knowledgeable people here on the forum would care to speculate on what might have been the reason it did this. 

It was dry where this happened, the water heater wasn't leaking anywhere, it just seems like there was a lot of resistance there, so much so that it melted the wire and part of the housing, didn't trip the breaker and I'm guessing that was because it wasn't a sudden 'jolt' for lack of a better word. The water heater is at least 10 years old. 

Thanks so much for any and all insight on this............


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## hdavis (Feb 14, 2012)

Looks like a bad connection. Over time it oxidized and gets worse.


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## Fouthgeneration (Jan 7, 2014)

Nicked wire, too small of wire gauge for element size? Wrong Voltage element.... leaky heating element water vapour eventually oxidized contact on thermoswitch....see water damage on heating element threaded fitting? High low heaters wired improperly.... old age/ just wore out. Over or under Voltage supply creating an over current load exceeding the rating of the switches/wiring....

wire with too low of temperature rating insulation for Hot spot and current load. limp wrist on screw torques, part timers might want to use inch pound torque wrench/Tee-handle driver.

Over insulated confined space created hot spot, heater jacket install 
incorrectly or too much extra material installed over wiring......

gas heat/hot water clothes dryers are far cheaper long run then electric, that is money that could be split between You and your renters......Even in Californiastan

partially wore out(shorted but not not dead short) heating element drawing more than rated Ampereage = melted wiring.

If the heater doesn't leak, the parts are less then 40.00$ to replace the heating coil and t-Switch, a little more for "mud hog" long coil that will last much longer then the tank..
A good time to flush the tank clean.


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## 91782 (Sep 6, 2012)

I just replaced a Decora outlet. The sparkys on my place just stabbed the wires in the back instead of using the screws.

Here's the problem: this outlet was used for an oil filled space heater.

Over time, the hot carried so much current for such a long period of time - the contact point would heat/cool/heat/cool until it got loose, then corroded, etc.

When you put the new one in, pull the cover and snug the screws. Life will go on.


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## Rio (Oct 13, 2009)

Thanks for the insights and observations! The reason it's electric is there's no natural gas available here, could do propane but am going with solar photo voltaic.

Of all the suggestions of what might have caused the problem I'm thinking old age/just wore out or a damaged heating element. I noticed when I was installing the new unit that there was a big warning (actually a couple of them) warning against turning the unit on before it was filled with water and I know one time it had been partially full when it was running.

If I remember correctly the P&T valve had started leaking, the tenant turned off the water but didn't throw the breaker and it had been spitting boiling water out.


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## hdavis (Feb 14, 2012)

Forget about a bad element shorting out, that just trips the reset or breaker. I've pulled elements that were turned into pretzles. The wires looked cherry because they're sized for the breaker, they'll handle full rating right up to the breaker tripping. 

The only way to get significant heating at that location is to have resistance to go up at that location.


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## hdavis (Feb 14, 2012)

Running them low or no water burns out the element, it just gets too hot. Put a new element in, and you're good to go.


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## Fouthgeneration (Jan 7, 2014)

If a vacumn breaker/ one way valve has been installed on the apartment water service, you need a correctly sized expansion tank for the hot water heater so the home plumbing doesn't go over its designed maximum pressure when reheating the hot water tank from a major draw down( like a shower/laundry day)

And check that the water service never exceeds 75 PSI, if it does, you need a pressure regulator device. Other San Diego posters have had issues with failed pressure regulators & no regulator with 110 psi and up line pressures(relief valve always dribbling, very short HW heater lifetimes) and the Water utility change service pressures with out any communication with customers: And all pressure regulators are the customer's responsibility according to SD water dept..... 

Very long, Mud hog elements can run "dry" with out damage to the element, and only cost a few dollars more than the short ones.


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## RangoWA (Jun 25, 2014)

Probably a flakey connection as said earlier but it didn't help that the temperature was maxed out.


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