marathon water heater

[rjwrong]

Having problems with my water heater heating my water too hot. I turned the thermastats all the way down to 110, but out of the tap it seems way hotter, cant keep your hands there long anyway! I dont quite understand how to diagnose an a/c electric circuit, but live in the middle of nowhere and was hoping for some help. Searched the archieves but cant seem to figure out what is wrong. I was thinking the thermastats where bad, but here an audible click when the upper and lower are turned up higher, and there is about a 220 volt drop across both heating elements. Stumped!!, any input would greatly be appreciated. I was gonna try a infared temp gun on both heat element areas to see if could condemn one of the thermastats that way, but unsure if it will be a accurate diagnosis. thanks jrw

[PipeDown]

First get a thermometer and get an objective reading of the water temp. I don't know if you are just sensitive to hot water.

Knowing the temp of the heating element is irrelevant. It is either very hot or not. The element itself is not temp regulated. There should be 220V across the element when it is on and 0V when it is off. Turning the thermostat knob should be able to achieve both on and off states.

If it is always on, that's definately a cause of hot water, there must be another thermal breaker keeping it from boiling if that is the defect.

The thermostat or sensor still may be defective if it is far out of calibration but otherwise working.

[Speedy Jim]

An element which faulted internally to the sheath will draw current (and heat the water) even with thermostat off. Typically, the thermostat opens one side of the Line, allowing current to flow from the other Line to Ground.

Jim

[pipedown]

That can be checked by using an ohmmeter to measure continuity and verify there is some resistance between the heater terminals and open to everything else (like the metal case and pipes).

[rjwrong]

ohm tested the elements- 13.0 on one and 13.5 on the other; no continuity to case or pipes; still stumped-how or is there a process to re calibrate the sensor or thermastat or just replace. The thermastats- both at set at the lowest settings-110, the water temp at the faucet is about 115 which is probably okay. See I think yesterday when I was playing with the thermastat swith- the lower stat never clicked until about the about the 3rd time turning it and there was no voltage on the element, but I wasnt sure if I just didnt here it and my meter leads were right or not, so I just passed by it. Today I think things are working okay. Would a lower stat switch cause an over heating water problem? thanks for the input!! JRW

[rjwrong]