how can i tell if my upper or lower themostat on a water heater is defective?

Answer 1

if your water heater is completly cold the top element should come on if it doesnt either the element or the thermostat is bad ...you have to check this with a voltmeter....if there is power 220 volts on the top element...you should be able to hear it heating the water as it will make a sizzling type noise...you will have to wait until it heats the top part of the water heater befor the botttom element would come on....the top thermostat does control both elemnts but the bottom element has its own thermostat to detect water temperature..you test the bottom element the same way you test the top element...plus there is a red reset button on top of the top thermostat that wil kick if there is a overheat problem ....just push on the red button to reset it...

Answer 2

stat hit the nail on the head. But here's additional info. Check your upper element first if it has 220 volts, you need to wait for the top half of you heater to get warm for the thermostat to shut the power to your top element and send it to your bottom element, then check the bottom element. You will never have power to both elements at the same time.

Answer 3

If you had to ask this question, you probably aren't qualified to do what is necessary to find out the anwer.

Also I think you will find there is only one thermostat but two heating elements.

You can use current draw or contact opening and closing to determine if the thermostat is the problem.

Most likely, it is one of the elements and not the thermostat.

Answer 4

with a volt meter, check the current at each element should show 220 volts across each screw, be careful,