My GC 7320 keeps leaking all the water in tank can this be repaired ? If so how much ?

check the elements [electric ones ] and water connections as well as relief valve if all dry then rusted out or cracked tank

Hi -

If your water heater is working (ie: making hot water) then most likely your heater isn't leaking. Rather, the leak is coming from the cold water supply and running down the tank where you see it at the bottom of the tank. A working tank that is leaking would produce a leak of hot water - not cold. You should carefully check the cold water piping for a leak, drip or stream of water and make the required repairs.

Tank is rusted out:
Replace tank
http://waterheatertimer.org/Leaking-water-heater.html

Gene

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

The use-and-care manual says that the 'product will eventually fail,' and to install a drain catch pan.
The product has stainless steel tank with 3 year warranty. 1-800-558-5700.
The manual does not show parts diagram, element, or anode rod. This indicates that operation is inside a sealed 1-piece unit not meant for repairs.
High clorine content of water, and hard water, and water pressure over 80 psi will adversely affect any tank heater, and shorten lifespan causing probable leak.

Turn off power:
If you can remove cover from H770, then inspect 750 watt element for possible leaking. Then replace with new element of unknown type if element is leaking.
If leaking is coming from the tank itself, then the unit cannot be repaired. This is true for all tank water heaters.
http://waterheatertimer.org/Leaking-water-heater.html
http://waterheatertimer.org/How-to-install-under-counter-water-heater.html

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

If pipes are leaking, then that can be repaired.
If tank is rusted out and water escaping from the tank, then turn off the water plus power to the heater for safety, and then replace water heater.
Rusted water heater can be welded for repair, but remember that hot water is under pressure and tank can rupture any time.
Safest course if to replace heater.

Open following link for leaking water heater checklist:
http://waterheatertimer.org/Leaking-water-heater.html

If water heater is leaking, then open following 2 links to avoid tank rupture and troubleshoot leak:
http://waterheatertimer.org/Emergency-steps-for-leaking-water-heater.html
http://waterheatertimer.org/Water-heater-is-leaking.html

Open following link if you want to install your own gas water heater:
http://waterheatertimer.org/How-to-install-gas-water-heater.html

To have gas water heater installed, can run $2-300 for installation plus cost of heater.
40 gallon natural gas water heater at Lowes starts at $300+, and tanks with longer warranty cost more and last longer.

If you maintain the tank: keep chemicals out of same room as water heater, attach bare copper ground wire between hot and cold pipes, flush tank each 6 months, clean burner each year as shown in manual, read the manual entirely for specific information about your model, and inspect/replace anode rod every 2-3 years then basic 6-year tank can last much longer.
http://waterheatertimer.org/Replace-anode-rod.html
http://waterheatertimer.org/9-ways-to-save-with-water-heater.html

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

I wrote a page on leaking water heaters with resources and information:
Page lists things to check.
http://waterheatertimer.org/Water-at-bottom-of-water-heater.html

Also run hand over tank to find warm spot that says where leak is coming from
A rusted tank cannot be repaired.

If your tank is rusted out, it might burst open and flood the area.
Hot water inside tank is under pressure.
Turn off heat source to water heater.
Turn off water valve located above tank.
Open tub faucet on hot side and relieve pressure from tank.

You can limp along with a leaking water heater by turning it on when hot water is needed.
For example a shower uses 5-9 gallons hot water.
Turn gas water heater on for 15-20 minutes.
Turn electric on for 20-30 minutes.

To conserve resources with next heater:
http://waterheatertimer.org/9-ways-to-save-with-water-heater.html

If it is actually leaking from the bottom of the heater, then it cannot be repaired. Have you looked to see exactly where the water is coming from? Sometimes a leak at the top of the heater, will then leak through the insulation and out the bottom. Another possible source could be from the temperature/pressure relief valve leaking and coming out of the down pipe that goes near the floor or drain. Try to find the source of the leak. It is not practical or safe to repair a tank that is leaking.