My electric hot water isnt workin! My unit is 10 years old GE10074 240 volts AC only-45 gallons. 4500 WATTS. The cold water runs fine-NO HOT-what could it be.GE model#:GE38S06AAG Serial#305D10074

On 240 volt system the currant draw is 23 amps And on 110 volt system the draw is 50 amps . If the wiring can handle the above load plus the safety margin it would be safe.

No.
Fold-back elements are low-watt-density, so element does not burn out as easily since heating is spread across more surface area. But recovery remains 16 gallon per hour.
20 amp breaker and 12 gauge wire: max 3800 watts
30 amp breaker and 10 gauge wire: max 5800 watt.
4500 watt element heats 20 gallons per hour.
http://waterheatertimer.org/How-to-replace-water-heater-element.html
http://waterheatertimer.org/Increase-amount-of-hot-water.html
Instead of changing elements: Set thermostats higher so more cold is added to hot water, and then you have more hot water available inside tank.
Gene

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

Your residential water heater is not 9000 watts. Or it would blow the fuse every day and melt the wire. Instead, you have dual-element non-simultaneous 4500 watt water heater.
http://waterhatertimer.org/How-it-works.html
http://waterheatertimer.org/Figure-Volts-Amps-Watts-for-water-heater.html
Look at label for 'total connected watts'
http://waterheatertimer.org/images/Whirlpool-energy-smart-watt-rating-IMG_2600.jpg
25 amp breaker or fuse and 10 gauge wire is minimum acceptable for 4500 watt water heater.
http://waterheatertimer.org/Color-code-wire.html
Troubleshoot blowing breaker or fuse:
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#trip-breaker
Why does it blow fuse once each year?? I don't know.
Fuses and breakers trip when overheating occurs on wire.
Each fuse or breaker is rated for heat, and over time, it will get hot and then cool and then get hot again ... this action weakens fuse or breaker.
To solve problem: install 3500 watt elements (and clean sediment out of tank). Wire will run cooler, and fuse will last longer. Whole fuse box will demand less power, and run cooler, and will last longer as a result. So there is less stress on electric service panel.
http://waterheatertimer.org/How-to-replace-water-heater-element.html
3500 watt element will heat water to same temperature, but takes longer. For example: 4500 watt heats 21 gallons per hour, while 3500 watt heats 17 gallons per hour.

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

test the thermostat and the heating elements --also there are resets that can pop push and make sure they have reset

the elements are 4500 watts this is what most all heater come from the factory. What you need to check is the amps.

Now with that aside, whenever I have gone to a home and I am told the the water heater is running to much I think leak under the slab. I dont know where you live but if you dont have a basement. I would look hard at that.

To do the K I S S test turn off the cold water feed to the heater tonight before you go to bed. when you get up in the morning feel the hot side and if it cold thats good. Now the test. turn on the cold water valve if the hot pipe starts getting warm or hot you have a leak and the wate heater is running all the time.

Hows your water bill too? higher ?? if so that leans to a leak also

Hope this did you good.

If you need we can set up a phone chat and I can talk to you about how to fix it with out spending over a 1,000.00

Best of luck

Tom

Are you asking about tankless gas or tankless electric?

You posted under Tankless gas water heater: gas type tankless plugs into standard 120Volt household outlet to power circuit board. You need larger gas line than used for tank-type gas water heater.

If you are asking about volt and amp draw of Tankless electric, then that depends on specific model number.
For example, if each tankless element draws 3500Watts, and unit has 3 elements, you will need 3 additional 20 amp 240Volt circuit breakers. Volts x amps = watts. 3500 watts divided by 240Volts = 14.58 amps. At full blast, this unit would draw 43.75 amps and will cost more to operate yearly than tank-type electric water heater. If unit has 4500 watts elements, then it will draw 56 amps at full blast, and use a good percentage of household power.

Tankless water heaters have no hot water in power outage. This is true for gas and electric models.

Additional resources:
http://waterheatertimer.org/images/Compare-water-heater-parts-650.jpg
http://waterheatertimer.org/pro-n-con.html
http://waterheatertimer.org/pdf/Bradford-White-on-demand-tankless-service-manual.pdf

A) Calculate date of water heater manufacture from serial number located on side of tank:
http://waterheatertimer.org/pdf/WaterHeaterSerialNumberDecoder.pdf
Date of manufacture is not date of installation.
Warranty is usually from date of manufacture
Serial number also shows tank size in gallons, tank volts and watts, and whether tank has 1 or 2 elements.

B) Troubleshoot leaking water heater:
http://waterheatertimer.org/Water-at-bottom-of-water-heater.html
Several things can be looked at to see where leak is coming from.
Carefully go over tank pipes and valves to eliminate every suspect.
Final suspect: tank is rusted out.

C) If tank is rusted out, then tank needs to be replaced before it ruptures.
Ruptured tank can cause major damage and water runs until shut off.
To prevent rupture, turn off power to heater, turn off valve located above tank, open tub faucet for a moment to relieve pressure on tank.
Turn on heater only when needed until new tank is installed.
4500 Watt water heater produces 21 gallons hot water per hour.
Shower uses 6-9 gallons hot water. Bath uses 12-14 gallons hot water.

"It is possible to limp along with a failed water heater if the leak is slow and if you turn off power and water when not using hot water. That trick could buy time, possibly up to 3 months. With time, you can consider how to make the system do more for less as well as comparison shop, get competitive bids, etc"

D) Now you're home is safe from damage.
If tank is only 5 years old, it rusted out pretty quick.

There are three things you can do so next heater lasts longer.

1) Learn about anode rods, and inspect anode rod every 1-3 years.
Loosen anode rod before installing new tank so replacement is easier.
http://waterheatertimer.org/Replace-anode-rod.html

2) Attach electrical ground wire between hot and cold pipes to prevent stray current from reducing life of water heater
http://waterheatertimer.org/9-ways-to-save-with-water-heater.html#straycurrent

3) Flush tank each 6 months to prevent sediment
http://waterheatertimer.org/Clean-sediment-out-of-water-heater.html#flushelectric

The Rheem water heater uses 4500 Watt elements
Check label on side of any appliance to see electrical rating details
2 element tank with two 4500 watt elements is still a 4500 watt appliance since both elements are never ON at same time.

Volts x amps = watts
amps = watts divided by volts

amps = 4500 divided by 240Volts or 220Volts
amps = 18.75
Your water heater uses 18.75 amps to 20.45 amps

Your 25 amp breaker should only carry 80% of rated value
25 amps x 80% = 20 amps.

So your water heater breaker is correctly sized.
You should have a 10 gauge wire going to this water heater.
12 gauge wire is a bit undersized for 4500 Watt water heater
Feel the water heater wire to see if it is warm.

If the main breaker is getting hot when 20 additional amps are being used by the water heater.
1) The house is using more amps than your 100 amp main can carry
Using the formula, 100 amps x 80% = 80 amps for the main breaker
Add up your total amp draw.
For example if your 3500 watt oven is ON, it draws 16 amps.
If your 5000 Watt electric heater is on, it draws 23 amps.
Your 1500 Watt 120V microwave draws 12.5 amps.
Add these numbers up plus your water heater, and it comes to 71 amps.
71 amps is getting close to the max 80 amp, but it's not over.
Now if you have a pool pump and and hot tub and a table saw going, the main breaker could be overdrawn.

2) To solve the problem short-term, you can put a timer on the water heater and use it only when needed.
http://waterheatertimer.org/Compare-13-electric-water-heater-timers.html

3) The main breaker is bad and needs to be replaced.

If you need help figuring circuits or timers, add a comment and I will help

The water heater has two 4500 watt elements.
However both elements are not turned-ON at same time
So the water heater is 4500 Watts

Volts x Amps = watts
Amps =watts divided by volts
Amps = 4500 Watts divided by 240 Volts
Amps= 18.75

So that says a 20 amp breaker ... except for the 80% rule
80% rules says for safety, your Amp rating should be multiplied by 80%

20 amp breaker X 80% = 16 amps
20 amp breaker is actually safe for just 16 amps, and your water heater draws 18.75 amps.

The calculation shows you need a 30 Amp breaker.
30 Amp breaker requires 10 gauge wire.

http://waterheatertimer.org/Figure-Volts-Amps-Watts-for-water-heater.html

The hot water heater should come with an amperage rating on it.
They vary from 30 to 40 amps, and then 10 or 8 gauge wire.
(All hot water heaters are 220 volt.)
I believe the 602 uses a 4500 watt element.
Divide 4500 by 220, and you get about 20 amps.

If you want to be on the safe side, you go with the heavier wire, 8 gauge, and then go with the smaller breaker that is more easily tripped, 30 amps. That way you can switch to a 40 amp breaker in the future, without having to change the wiring. The goal is to always make sure the wire is rated higher than the breaker. You want you breaker to trip before your wire melts.
But technically a 30 amp breaker and 10 gauge wire would be fine for this heater.

And since it is 220 volt, you will always use a double breaker.
That is because 220 volt appliances don't use a ground, but instead use the potential between to power wires that are 180 degrees out of phase. AC always does a sine wave, and the 2 power leads coming into the house are always out of phase. When one is 110 volts up, the other is down. So the total between them is 220 volts. And the way they intentionally zigzag the breaker box, 2 breakers next to each other always are on opposite power lines.

If you have any doubts at all about 220 and water heater wiring, please ask again. Wiring is not hard, but you have to understand what you are doing, or else you can cause serious consequences.
For example, if you use wire nuts or wrap wire around a screw, you need to always turn them clockwise, so they pull the wire when tightened.
You also always need to ground the chassis with a green safety wire.
Since a 220 hot water heater uses 2 power wires and a safety ground, the white wire should be striped with a permanent marker, so that it is not confused with the white neutral wire of a 110 volt appliance.