Keep throwing breaker both element are good do they heat togeather are alt. bob ferguson

Breaker keeps tripping means short in wire or heat element
Shut power off . use ohm meter and go from ground to each wire on elements and if you get continuity. there is short pull wire off element check wires to ground not continuity bad element.
still shorted follow all wires may have bare wire shorted against cabinet Or by new heater

You could have a weak breaker, Check the amp draw on the breaker while the heater is running and if it is not pulling more amps than the breaker is rated for replace the breaker, If it is pulling more amps than it is rated for you have a element or thermostat going out and causing to high of a amp draw throwing the breaker. Good Luck

Copy following link:
http://waterheatertimer.org/Water-heater-is-blowing-breaker.html

Hatco booster heater typically has 2 sets of thermostats and elements located on each end of heater.
Both sides might be controlled by same 60 amp breaker, or the heater might be controlled by two separate 30 amp breakers.
Be sure you have correct wire and breaker.

After reading steps on link above, add comment and say if this is new installation, or older installation that suddenly started throwing breaker.

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

Appears to be a short in tank circuit probably cause by a water leak in tank. These usually wear a rusty hole in the tank inside the cover and are not seen unless the thermostat covers are taken off. I would remove them and do a visual thoroughly. Anytime a fuse blows or a breaker trips is always a dead short unless you have a bad breaker. I would check those as well for vibrating, chattering noises, and/or smoking. If any of this persist, replace breaker. A melted heat element could trip them, but not usually for it leaves an open circuit instead of a shorted one.

It could be element shorted to ground through steel tank, so don't touch tank when breaker is ON.
Or you have undersized 12 gauge wire and 20 amp breaker and the heat has loosened breaker on the busbar. Breaker trips when heat exceeds breaker limit. Jiggle breaker and listen for crackling sound.

To restore hot water now:
Turn off circuit breaker, and open top cover then Push in reset button on top of heater to restore functionality. Put back insulation and factory cover.
To fix water heater: test and replace bad element.
http://waterheatertimer.org/How-to-test-water-heater-element.html
If problems continue
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html#trip-breaker
http://waterheatertimer.org/Troubleshoot-household-electricity.html

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

IT SOUNDS LIKE YOU HAVE A BURNT OUT HEATING ELEMENT YOU PROBABLY HAVE TWO IN THIS UNIT CH YOUR CERKET BREAKER FIRST IF OK DRAIN THE UNIT TURN BREAKER OFF RE MOVE ELEMENTS THAY ARE BEHIND THE COVERS THAY HAVE PHILIP'S SCREWS TAKE THEM TO LOWS OR HOME DEPOT MATCH WITH NEW ONES PUT THE NEW ONES IN FILL THE UNIT WITH WATER OPEN A WATER TAP LET RUN TILL ALL THE AIR IS OUT THEN TURN THE POWER BACK ON HOPE THIS HELPS GOOD LUCK BOB

sorry to say but when you drain an electric water heater and dont turn off the power to it . the elements fry. so make sure breaker is off drain tank and replace the elements refill and then turn breaker back on and all should be fine.hope this helps have a good day!

Take off front cover, on the top of the two cylinders in there (the heating system) there will be a small red button. That is the Safety Thermal Cut out, depress that red button. It is similar to a circuit breaker. If the red LED comes on when you turn on hot water at a sink then that was the problem. I have on that trips periodically. Its annoying but not enough to replace the part yet. Good luck.

The circuit breaker keeps getting thrown yes? Alright then, you may have a bad element inside the water tank. If you don't know what a circuit breaker is then please call a plumber and do not go near the water heater as it may be a danger to your well being. However, if you do know, then go out there and throw the breaker to the water heater. If you are not sure about this or can not test the voltage at the water heater then do not proceed. However if you are sure, then take off the little covers from the side of the tank and look at the insulation as it may appear moist or wet. There is a heating element inside the tank which can break off, cause electrical shortout and allow water to leak out into the insulation. How to Fix: Shut off the cold water supply at the top of the water heater, then go to the nearest sink and turn on the hot water. There should be no water pressure if you shut the supply valve going into the tank. Now then, leave the hot water turned on at the sink as this will provide a vent for draining the water from your water heater. At the water heater there is a small valve at the bottom which when opened will drain the entire volume of the tank. I suggest that you find and connect a hose to this valve prior to opening it so that the escaping water goes outside rather than on your floor or you could just call servpro and let er rip. Either way, while the tank is draining look on the side of the water heater and find out if it is 240vac or 120vac and write this down. Now look to find the wattage of your heating elements. It might be 1500 watts, 4500 watts or 5500 watts, write down the wattage indicated for the heating element you are about to replace. Write down the brand and the model number along with the voltage and element wattage and go to your local hardware store. Ask one of the older guys (not the kid in electronics) if they would help you select the proper heating element for your make/model and also ask if you need an element wrench to install the heating element which you are purchasing. If the answer is yes, then get that to as you will be needing one very soon. Back home your tank should have drained completely. Now on the face of the old element will be two wires; remove them. Take your nifty little element wrench that you just bought and remove the old element. You will probably be amazed to find that the old element is like, in two pieces, and that's because the rest of it has fallen off inside the tank. If you can retrieve the part left in the tank then do so however it will not be a problem if you can not. Disregard the white hard water build up inside of the tank unless you have the time and capacity to dig all of it out through that little hole. Although, you may need to wallow it out a tad so that the new heating element can fit inside. The new one will replace just as the old one was removed and do not over tighten (it just needs to be snug not twisted off). Replace the two wires; either way don't matter. Then shut the drain valve and open up the water supply on top. Your hot water tap in the nearest sink should still be turned on and now you should hear the air escaping from inside the water heater tank as it is being filled with acid. No just kidding, it is filling with cold water. When the tank is full, water will run from the tap and only then may you shut off the tap. Now with the tank full and the new heating element wired up to the thermostat you can throw the circuit breaker back on. Congrats. Within in 30 mins you will either have very hot water or you will hear an explosion louder than anything you have ever heard in your life. As long as you followed the filling the tank till the water runs out your faucet bit, you should be good to go; go take a bath that is.

Did you check to make sure that the breaker is good on the unit? Check to make sure you are getting voltage. If not, check to make sure that the thermostat located in behind the panel on the heater is getting voltage and also sending voltage to the elements. If the elements are getting voltage but aren't heating, the element(s) is bad.