Hot Water Heater High Limit Switch Continualy Trips

[rshackleford]

i just moved into my new house. the previous owner said he had problems with the hot water heater. he said he had to go down and push a little red button ever once in a while. it is an electric heater. i have had to push the button three times already today. i think it is the high limit switch.

what is this a symptom of?

[rshackleford]

Update

just took a huge bath and i am sure i emptied the tank. the red button was tripped again and no new water was being heated.

[Redwood]

The red button is indeed a high temp limit. There could be a few different reasons for it to happen, If you are handy with a meter it is not too difficult to isolate the problem.

Have a good read here.

I wrote that after answering the question too many times on forums.

[rshackleford]

i did not realize there were two thermostats. the top one was set at "B" and the bottom was set to "Very Hot." i am assuming there was some sort of gradient setup and the bottom burner would heat the water and the hot water would rise and I guess that this would keep happening until top water reached a temp that tripped the high limit. the heater has not tripped out now since i discovered this.

both elements are 3500 kw and they ohm at about 12 ohms. i have 240 volts on the top element and not the bottom when the top thermostat is heating and 240 volts on the bottom and not the top when the bottom thermostat is heating.

i will be back if it trips again.

[rshackleford]

it still has tripped a few times.

tbe last thing i did was to set the upper thermostat just a bit higher than the lower. this seems to have taken care of the problem for about two weeks.

[Redwood]

If you follow the tips in that link I gave you above you will solve the problem.