[Almost Retired]

if the HO changed any thing .
i would double check thermostat and element wiring.
also check both tstat temp settings
also possible that a new tstat is bad

New tstats arent always the same wiring
incorrect wiring could leave an element direct connected
they wont notice how hot the water is unless they run some just before or after it trips
i have found it usually takes about 30 mins to come up to temp and shut off, you may have to wait and do that to find the problem

down here they are designed to run one element at a time with 2 tstats.
the upper tstat controls its element and the lower tstat.
the lower tstat only controls the lower element
both tstats have a red button that is heat activated and opens a contact to shut off the current for hi temp
the upper element should run until tstat is satisfied, then switch power to the lower tstat
the lower element should run until lower tstat is satisfied and switch off

there is internal plumbing that a lot of ppl arent aware of
the cold inlet side for the water actually has a tube extending to near the bottom of the tank
the hot outlet is at the top
hot water rises, cold sinks
this way you get the hottest water in the tank, even if the lower element is currently running

 

[Almost Retired]

Very rare to find a residential tank that runs both elements at the same time.

so far i never have

 

[Almost Retired]

i may have seen that, but dont remember it

 

[Almost Retired]

you are probably correct about no lower, been a while

 

[Almost Retired]

Is this a ECO tripping?

Chances are the dip tube is cracked or broken and cold water is bypassed and the units is over heating where the limit is.

if the unit was over pressure or temperature in a unsafe condition the TPSV will open.

If a old tank scale build up can cause this as well but rarely. Usually the efficiency is noticeably reduced.

by ECO do you mean brand?
he said newly installed new tank was doing the same as the old tank
then the ho changed tstat
then called him
i suspect he solved the fuse blowing when he replaced the disconnect

 

[Almost Retired]

here are diagrams of the most popular brands locally

 

[Almost Retired]

I got a service call to check out a hot water tank that was blowing fuses.

have you fixed it yet ?
come on we worked hard to help you
let us in on the victory celebration LOL