Water temperature question

I just built an electric all grain system with two kettles (HLT and BK) that I installed heating elements into and a round cooler mash/tun, am I ever glad I spent the time doing so, it heats the water up much quicker then when I was brewing on my electric stove.

I have not started brewing yet with my new setup just testing the system with plain water to insure there are no leaks and that everything works. Now the question I have is, is it normal for the water UNDER the heating element to be colder than the water above it? I find that I have to stir it up to make sure the water is evenly heated. The temp probe (which is way above the heater) was reading 160 degrees (also confirmed by my hand held thermometer) after a few minutes . The outside walls of the kettle was also hot but when I moved my hand down to the very bottom (below the heater), there was a big temp difference, it was cold! I used my paddle and stirred the water and as I did I watched the temperature and noticed that the temp started to drop confirming that the water temp below the heaters was actually colder than the water above it.

Is this normal for an all electric setup?

 

This is normal for almost any setup. Unless you get that boil going you are going to get thermal stratification. Also how far from the bottom are your elements?

 

About an inch or so, they pretty much line up to the same height as my wall drain valve.

 

You can recirculate water with a pump (or stir a log) for a consistent strike water temp

 

I did a 11 gallon batch (12.5 gallon pre-boil) with a 4500W 240v heating element. My AL kettle does not have any insulation and it was 30-40 deg F outside. After reaching a boil, element is at 70-80% power to maintain a vigorous boil. A lid does help get to boiling temps faster but 4kW should be plenty of power.