# rheem marathon tanks ? help



## seanny deep (Jan 28, 2012)

Installed a 40 imperial gallon tank that a customer supplied a few years ago and he just called high limit keeps turning tank off and thermal expansion valve keeps dumping.. any ideas im thinking faulty thermostat maybe ? I dont have alot of experience with these tanks do you guys have any suggestions. Any advis or input would be greatly appreciated thanks seanny


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## ZL700 (Dec 8, 2009)

Besides a faulty thermostat

If an element has a crack it can still read correct ohms when measured screw to screw. But the crack means there is also a path for electricity to flow to ground and thereby continue adding heat to the water even though the thermostat opened. The thermostat only opens one leg. Unless hot water usage is greater than or equal to heat production the ECO (emergency cut out, red button) will trip.

The above can be verified with a amprobe


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## Master Mark (Aug 14, 2009)

its just an electric water heater.. there is nothing special about a rheem marathon heater... 

do the normal routine ... change out the elements , clean the sediment out and you should be fine


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