82v52 2 burnt switch behind the bottom plate with the red/black wires going to it. Is this replaceable? How does it come out if it does? Thank you so much!

The element is right behind that panel,sounds like that is whats leaking. The elements just screw in or have a plate that compresses againt the element and gasket. Either way sound like a simple fix be carefull those wires are 240 volts most of the time inless its a small water heater.
Lowes has the elements just shut off the power and drain the heater before you start. If its an older heater it will be rusted any may not come out,just be ready to a buy new heater if you cant remove the element and damage the heater due to all the rust. Good luck

I'm thinking when you say black box, that you also have a wall switch with a symbol like a lightning bolt and you switch that on as well as checked breaker panel to make sure breaker is on as well.
With that said, you'll have 2 of 3/8" nuts holding that black cover on. Remove top one and loosen bottom one and pull cover off. ( Be sure power is off to unit while doing this.) You'll find the element in behind it. Put a voltmeter on black to element (red probe or alligator clip) and (black probe) to ground where you see green wire connected to tank. Turn breaker on then switch at wall. You should hear a relay click and 120 Volts should show at black wire ( red probe) . If you've got 120 volts there, shut off all power, drain water heater and replace element.

if the switch is rated for 240, then hook up the same way but use the 110 black and white wire for 110 volts to switch, instead of the red and black wire for 240 . on 110 black wire is always hot and the white is the neutral wire. the best wire to use is 12/2 with ground.

There is a reset button located behind the top cover plate on the side. Remove four screws to remove cover and carefully spread insulation apart to access element,thermostat, and reset button. It is a small round red button. If you push it in and it stays thens the element should come on. If it pops right back out then you need to look at changing the reset.Thank you.

The red reset button will be on the upper thermostat , behind the top cover, if you push it and it clicks, the water will start to heat, but you are not out of the woods the upper thermostat must be replaced. Easy job, turn off the power and take a digital picture of the wiring, remove the old one, only has two clips at the bottom that hold it to the tank, do not bend these just spring them out far enough to get the part out. When you put the new one in make sure it is pushed tight against the tank, and there is nothing between the two. Rehook the wiring and turn the power back on.

Your upper element is burnt out. open top cover, turn power of at breaker panel,drain hot water tank . remove black and red lead wires from the element use a socket to un thread the 3000watt 240 volt screw in element. re install the new element atach wires to element. Fill tank with water before turning on power or you will be replacing both elements very shortly

Your 220v hot water heater does not need the neutral(white) wire coming in. Bare wire goes to ground -green headed screw. Black goes to black, Red goes to red. White gets teminated with a wirenut or some electrical tape.

when you replaced them did you bleed all of air off tank before restoring power to w/h if not you could have burnt the new ones , are you getting 220 volts at top of w/h and ck wiring again to be sure properly wired top comes first and when has reached set point of top t-stat it transfers power to bottom just like a 3-way light switch operates 120 volts always on bottom waiting on the other side of the line to heat the element on 220

the red are positive power + and mostaly connect to thermostad and from themostad trou the heating ellement and the black wire are the negative power - and connect to the heating ellemend and the yelow with green are grounded to the boiler

Have you checked for 12 volts DC getting to spark module ? If it's just the 2 wires going to spark module, Red and green, check for 12 volts at the red wire.
If it has the 9 wires on 2 connectors, check for 12 volts at Brown and Orange. If no 12 volts there, then you'll have to go back to switch and check there for 12 volts in and out when switch in on position. Let me know what you find.