Water heater reset is tripping.

rjniles

Not sure if the belongs in plumbing or electrical but I will start here.

Electric water heater about 5-6 years old (based on manufacturing date), looks in good condition, was here when I bought the house about 4 years ago. Woke up to no hot water about 3 weeks ago, found reset on upper t-stat tripped. Reset and water heater worked. About a week later, same thing. No hot water & reset popped out. Bought a new upper T-stat and installed. This morning, no hot water, reset popped out. I have inspected all the wire connections at the upper and lower t-stats, the disconnect and the supply circuit breaker. No signs of any loose connections or arching. Measured the resistance of the upper and lower elements with the wires disconnected. Lower element about 14 ohms and the upper about 9 ohms. I have drained the sediment on a regular basis so there is no build up in the tank. Can the upper element be bad and be drawing too much current or do I have a different problem? Any other ideas would be appreciated.

__________________
Location:
Coastal South Carolina

kenmac

use amp meter & check amps also check water temp

Plumber26

likely a bad thermostat,
You'll want to check the upper and lower elements.
Get an Ohm meter, turn off power, take one of the two wires loose from element, get an ohm reading (should be 11-13) by putting leads on both screws, if okay put one lead on one screw and the other hold on the tan of the water heater, if you get a reading of 11-13 on that then you have a grounded element and it needs replaced. If not, replace upper and lower thermostats (likely that is the problem)
5-6 years old, parts should still be under warranty

Ltnicks

check and double check the wiring is correct, make sure it is an appropriate t stat for your unit and installed correctly.

in some cases a universal t stat will not work on all water heaters, you may need name brand. but I am willing to bet it not wired correct

Plumber26

it has to be wired correctly to have worked for 5 years w/ no problems, likely just a bad t-stat but, check for grounded element just incase

Ltnicks

I agree, my concern is after the t stat was replaced that it was wired the same. when I repair electric water heaters I typically take a picture of it with my phone so I can double check my work, this I learned after the first water heater that stumped me

Plumber26

They are all pretty much the same (residentially, that is)
I always take the wiring loose and bend them in the direction they go. I agree though that you'll want to check and double check the wiring is correct if you've never done it before.... make sure all lugs are tightened and all wiring is secure... any signs of burnt wiring warrants replacement in my opinion. It is a big pain, if not almost impossible to rewire a water heater. Especially the way they are insulated theses days.

rjniles

Thanks for all the suggestions, I will have to do a little more testing. I am sure the water heater and t-stats are wired correctly and since the upper t-stat is new, I don't think that is the issue. But I guess the lower T-stat could cause the reset to trip. I did not test to see if either element is grounded to the tank but I would think that would cause an immediate trip of the reset or the supply circuit breaker.

__________________
Location:
Coastal South Carolina