It appears (from the markings) that someone has change the elements on this new water heater. Why would someone do that?
Faster hot water.
Not good.
Not good? Why?
It isn’t what the manufacture design.
Think presure relief for one thing.
did you check the size of wire?
What would that have to do with it?
If I recall correctly…Most that I’ve encountered have #12 running to the elements.
Only used on week ends so need a faster raise of temperature and it is shut off all week.
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Strikes me as very odd - a brand new water heater with changed elements - I would think that such a change would void any manufacturer’s warranty…
If you wanted something with more pop - why didn’t they just buy one?
just asking what size of wires extra amperage if the wire was under sized in the first place.Inquisitive minds needed to know . 4500 or 3500 shouldn’t make much difference thermostats and high limits in place. 4500 elements would need 10 ( 30 amp breaker) 3500 elements (25 amp breaker ) based on the 125 percent for the breaker
The one I have has 2-4500 and from cold to hot about 20 min.
How did you come to those figures?
Just askin’
Well since there is the need to call in a licensed plumber for other issues (no hot water in the guest bath tub) - I am recommending that the plumber review and comment on this issue while he is there!
Its an electrical issue.
It may well be - But the water heater is a plumbing fixture…
A plumber plums it an electrician hooks up the electric.
OK- Who changes the elements? I think that this is a fixture issue - someone has altered the fixture itself outside of the manufacturers apparent parameters.
Look for wire gauge and breakers Roy sorry in the middle of a report , or calculate watts to amperage and voltage .
4500/240=18.75
You might instinctively think that 12ga on a 20amp would work.
However, you need to size it 125% of the continuous load.
1.25 x 18.75= 23.43
So 25 or 30 amp breaker would work.
I think 
4500w /240v = 18.75 amps X 125% = 23.4 amps and this would require a 30 amp breaker with # 10 wire.
What about the excess heat those 4500 will create quicker as opposed to the 3500?
That is the problem wouldn’t you think?.