My brand new 40 gallon water heater is leaking from the top temperature control. it is the first time it has bin filled. i have not had hot water in 3 days. please help.

Gas or electric?
Electric water heater ... then test for crossover, check for water leak, replace thermostats, test elements
Gas water heater ... test for crossover, check for water leak
http://waterheatertimer.org/Crossover.html

http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

http://waterheatertimer.org/How-to-test-water-heater-element.html

water leak: turn off all taps and put ear against pipe and listen for water leak... check if water meter advances when all water taps are off.

Gene

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Doesn't sound like its the dip tube, its a element problem, I would contact bw directly to see if heater is stil in warranty and they will send you new parts free.

A leaking water heater cannot be repaired, assuming it's the tank leaking and not nearby water pipe.
http://waterheatertimer.org/Water-heater-leaking.html

First thing is to protect your property from catastrophic tank failure where tank ruptures and water runs until it is shut off:
Tanks are under pressure when they are hot.
Close cold water shut-off located above tank.
Turn control knob to 'pilot' so pilot is lit but burner will not turn on.
Open hot side on tub for few moments to relieve tank pressure.

Now your property is safe.
You need a new water heater.
In mean time, gas water heater makes 41 gallons hot water per hour.
Shower used 5-9 gallons hot water.
Bath uses 10-15 gallons hot water.
You can turn on water heater for short stretches and limp by until you get a new heater.

Steps for installing gas water heater:
http://waterheatertimer.org/How-to-install-gas-water-heater.html

If you'r really lucky you may find a leaking fitting on top of the water heater thats draining down inside the shell and out the bottom, otherwise its time to replace a rusted out water heater.
Sorry

For images and product information
For manual


You checked ohms, did you check for 240V across lower element when lower element is turned on?

Energy smart electric water heater has a control box on top of unit. Water heater does not have typical thermostats that can be tested and replaced. Temperature sensors located above each element send information to control box through small black and red wires. Temperature sensor sells for about $40, but there is no test listed that shows how to determine when sensors fail.

Potential problems:
-Temperature sensor is not reading correct temp
-Control box not processing correct temperature information
-Selector on control box set to 2, 3 or 4
-Thermostat temp on control box set lower than 120 degrees F
-Sediment build-up starting to surround lower element so water doesn't circulate (see if drain valve runs full-open

Yes, Turn the knob on the gas valve to off. Turn off the incoming water line into the water heater. If you have a valve on the outlet turn it off too. Open the drain at the bottom of the heater to drain a little water from heater. You can then lift the lever on the temperature/pressusre relief valve to let a little air in to release the vacuum and let the tank drain. If the relief is in the side let it drain a bit longer so the water level is below the outlet. Be sure to re-install the down pipe on the relief valve on the new valve. You should drain the a few gallons of water at least once a year from your heater, and you should exercise your temperature relief valve once a year to be sure it will function. If your new valve leaks suspect your temperature control allowing the water to get too hot.

the hot water tank may be filled with scale buildup on the inside. drain a few gallons out of tank until the water runs clear. it is best to drain out water heater at least 2 times a year.

How big is your bathtub? Is your water heater set on the hottest setting? What is the temperature of the hot water at the tap?

Keep in mind that hot water can cause severe burns. Children and those with diminished mental capacity can be seriously harmed by hot water.

The "40 Gallon" rating on the water heater is usually the amount of hot water the unit can produce in one hour. So the tank, and the amount of immediately available hot water, might be smaller than 40 gallons.

My bathtub is 2 feet wide by 1 foot deep and 4 feet long. This is 8 cubic feet or almost 60 gallons. So a 40 gallons of water at 120 degrees, mixed with 20 gallons of cold water (60 degrees), fills the tub with 100 degree water. My January cold water is 42 degrees, so it will take 40 gallons at 129 degrees to fill the tub. If the tub is cold to start it will take even hotter water.

So the water heater might be just fine.

Possible solutions:
1. turn the temperature up on your water heater- or the temperature control could be malfunctioning and not getting the water hot enough.
2. insulate your hot water pipes so that the water loses less heat on the way to the tub.
3. bigger water heater.
4. smaller bathtub, or less full bathtub.

You say a very new water heater. You won't get 40 gallons of hot water from a 40 gallon water heater because the continuing influx of cold water will cool your hot water down. However, it appears that your bottom water heater element needs replacing. If the top element is bad, you'll get no hot water. If your bottom element is bad, you'll get "some" hot water. Try replacing the bottom element. DON'T FORGET to turn off the electricity AND water first (closeby towels are also handy)!

my top element to the hot water heater is working but my bottom element isnt there both brand new elements and im just not getting power to the bottom element but i have power to the top element is it possible that the top heats first and the bottom heats later running out of options!!!