Question posted under marathon electric water heater.
Marathon is 240Volt dual element non-simultaneous water heater.
Non-simultaneous means that upper part of tank has to reach temperature before power is sent to lower thermostat and element. So if upper element is bad, then water heater has no hot water.http://waterheatertimer.org/Replace-anode-rod.html#audibleBW
1) You need to by-pass upper element without by-passing upper thermostat.
2) You should never by-pass upper thermostat because it has ECO-reset protection.http://waterheatertimer.org/How-water-heater-thermostats-work.html
3) Open following link for image of wiring:http://waterheatertimer.org/images/Marathon-wiring-700.jpg
4) Take photo of your wiring in case color code is different on your specific model
5) Look at upper thermostat.
Remove yellow wire from terminal 2 on upper thermostat, and cap off temporarily.
Remove red wire from terminal 4 on upper thermostat, and move it to terminal 2 on upper thermostat.
6) For more effective operation, look at lower thermostat.
Remove black wire from lower thermostat terminal 1 and move wire to terminal 2 on lower thermostat.
Take a moment and rate answer:
And take advantage of fixya expert assistance live.
For a price, expert works with you while you work on water heater or any do-it-yourself project.
Fixya is always less expensive than a service call.