Electic water heater doesn't work

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Mad Plumber, Jun 6, 2007.

  1. Mad Plumber

    Mad Plumber Mad Skills

    Messages:
    222
    I am trying to help my nephew get his electric hot water heater to work. We do not know why it will not work. I have tried testing it to see if it is getting the correct voltage, but do not know how to test it properly or where. I have a multi-meter, but also know that it has only two contact points. When testing for 220 where do you touch the common or negative (black) wire too? I have been told that to test the circuit breaker one touches both contacts to the two. screws and should get a reading of 220V. In checking your web site yesterday I read where test points are noted as Line1-Load1 or Line2-Load2. Where are these and how does one recognize them? It also stated that when the water is hot and the thermostat turns off the voltage will all be OV, escept for Line1-Line2 Where do I find these and how do I know where they are? The two contacts on the heating elements, are these Line1-Load1, say at the top and the bottom ones are the 2's?
    It the circuit breaker reads 220 but I don't get 220 where I test for the
    Line1-Load1 what would be the next step?

    Thank you for your help, it is greatly appreciated. Gramp
    gramp1863@comcast.net

  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,183
    Location:
    New England
    Electric water heaters are fairly simple. Power in should always be the 220vac. It goes to a thermostat, then to the heating elements. Have you tried to find the manufacturer's instructions on their website. It should have some troubleshooting, a parts listing and some pictures. Three things commonly replaced: heating elements, thermostats, and leaking T&P valves. Once in awhile, people will think to replace the anode rod before it is totally toast, and if they do, the thing might last longer. The thermostats typically only activate one heating element at a time.

    Assuming the more common wiring, they used a cable with black, white, and ground. There is no neutral on a common domestic WH, so between the black and white, you'll have 220vac. If you don't at the WH, you've got a problem. If the CB is on, and you don't have it at the WH, either the breaker is bad, or the wire is open.

    You could have a bad thermostat(s) or burned out elements. Turn the power off, remove one lead from the heating element and check the resistance (Ohms) between the two leads of the element...it should read very close to zero. If it is open, the element is burned out.
    Last edited: Jun 6, 2007
  3. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    Unless this is a new water heater if you replace both elements and the upper and lower thermostats you will save your self a lot of time for about $50.00-$60.00 and shouldn't have any problems for the rest of the water heaters life.

    Do you know how old it is.
  4. Cass

    Cass Plumber

    Messages:
    5,980
    Location:
    Ohio
    checking for voltage at the element screws won't help you. You need to check the resistance of the elements and see what amperage they are drawing if any.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,874
    Location:
    Cave Creek, Arizona
    water heater

    Checking voltage tells you if the element should be heating, testing the amperage tells you if it actually is. Ohms is a redundant test and cannot be made with power on to the heater.
  6. At the top of the WH there is plate under which the wiring from the panel connects to the WH. Both the black and white wires should be hot (110v each) and connected to the WH wires with wire nuts, and with the bare wire going to the green ground screw. Usually, WH wiring is 10/2-with-ground from a 30 amp double circuit breaker. Make sure that the wires from the panel have full voltage, and with the breaker OFF, double-check the wire nut connections.
    If the voltage is O.K. from the panel and the connections are tight, and they're getting no hot water at all, then the problem most likely is in the tstat(s). Sketch a drawing of the tstats screw layout and number of screws, and go to the store and get two (upper and lower) new tstats just like them (they do not have to be the same brand).
    With the breaker OFF of course, exchange each wire ONE AT A TIME from the old tstats screws to the new. Can't go wrong. If that doesn't resolve the problem, check the elements as suggested, or just replace them. If you need a step-by-step for that, just come back and ask. We'll be glad to help you.
    If that WH is getting long of tooth, I'd just replace IT, however.
    Good Luck!
    Mike
    Last edited: Jun 10, 2007
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,874
    Location:
    Cave Creek, Arizona
    heater

    If the voltage is O.K. from the panel and the connections are tight, and they're getting no hot water at all, then the problem most likely is in the tstat(s). Sketch a drawing of the tstats screw layout and number of screws, and go to the store and get two (upper and lower) new tstats just like them (they do not have to be the same brand).

    That is like a car not starting so you get a new starter, battery, ignition switch, and coil. Then replace everything. Why not find out WHAT is wrong and change that. It could just be a tripped ECO red button, and that could be caused by a "one time" anomaly or it could be a symptom of some other problem.
    Last edited: Jun 10, 2007
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