Checking Electric Water Heater Parts

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by white tiger, Dec 23, 2006.

  1. white tiger

    white tiger New Member

    Merry Christmas everyone! How do you use a VOM meter to check a heating element or a thermostat to tell if it is bad? What scale to use and what reading is an indication of failure? Any help would be greatly appreciated. Thanks love the forum.:confused: :)
  2. Cass

    Cass Plumber

    Elements may be checked by setting the meter for ohm's. Then take the probes and place one on each element connection. It should read between 11 -16 if the element is O.K.. Then go from each element connection to the element housing and there should be nothing between them. If you wish you can also extract the element and do a physical exam of it. You can also check with an amp meter while it is under power.

    The thermostats can be checked best with an amp meter also. There is no easy way to check with an ohm meter, unless hj can tell me one. You would need to trip the stat with a heat source applied to the back of it and then check it.
  3. Save time and aggravation

    I know that this may sound stupid,
    ok.. wasteful too, and possibly lazy

    I stopped trying to check out t-stats

    becasue it took too much time to heat the

    statt up on a light bulb to see if it tripped

    the circuit correctly.. ...then you chased ghosts

    trying to figure out wether the elements

    were still good or not too...

    Then you also need to make an x-special electrical tool
    to see if the elements are "gronded " or not..

    with any ohm meter they can still give a good reading and trick you...
    they can read good but still be grounded out....

    I finally threw in the towel and now just change everything out
    in one trip and completely eliminate return trips to peopels homes...

    If it is economically feasable for you

    just go to LOWES and buy an new upper
    and lower t stats and elements .. allfor about 40- 50 bucks.
    Last edited: Dec 24, 2006
  4. Cass

    Cass Plumber

    While I can check them I tend to just replace them, like MPM, also based on their age when I work on them. Everything has an expected working life and if the heater has any age on it I will just change out the elements and stats and tell the custome that based on it age I did that. It then gives the customer a very reasonable expectation that the problem is solved and an old element or stats, in the near future, can't just go bad because of age and normal use.
  5. customer satisfaction

    If I dont change everything out, I am

    almonst 90% sure I will be makeing another trip

    ---35 miles round trip ---back out there within two weeks....

    and of course they expect it for free,
    and they sort of wonder
    why in the hell did you did not just change it out on the
    first trip...

    of course they have had a cold shower or two
    and usually are not in a good mood about it all..
    if they have had to wait on me for a day or two..
  6. Randyj

    Randyj Master Plumber

    1st... use volt meter. Be sure your AC Volts are higher than the appliance. One probe to tank or other good ground. Place the other probe on "hot" wires to thermostat....on a 220v heater you should get about 110 volts on each side...(if not then you possibly have a breaker tripped on only 1 side). You should have about 220-240 volts across both wires. Then check the elements... 1st. check power to elements.. ground one probe then other probe to one terminal of the element...then other side... should get a good voltage reading... then check for continuity... turn off power to heater and make sure there is no power using volt meter.. remove one of the wires from the element..then turn meter to ohm position to check for continuity (this can also be done with lightbulb, battery and piece of wire)... any kind of continuity checker... one probe on one terminal and other probe on other terminal... if you get a zero reading then the element is broken... to check for ground, one probe to tank, one to the terminal(s) of the element. You can also just remove both "hot" wires to the thermostat and use probe to tank and other to each terminal the hot wires were on... there should be ZERO OHMS....
    How to check thermostat... not really sure...but with water hot it should shut off power to the elements. Makes sense to me.
  7. Terry

    Terry Administrator Staff Member

    Bothell, Washington
    It's like replacing your tail lamps.
    Sure you can save money and replace one light, and then wait a few weeks to be stopped and told the other tail light is out, and the warning or ticket to go with it.
    Or you just replace things in pairs.
  8. TNPlumber

    TNPlumber Plumbing Contractor

    East Tennessee
    I'm with MPM

    I do the same thing Mark. I used to take the time and check them thoughly, but now I just make sure the tank has power coming in on both wires, replace both elements and thermostats, and barring a dip tube failure, that will solve the problem.

  9. Randyj

    Randyj Master Plumber

    I check it out, give them my opinion. If they want me to stop there I will, if they just want new parts, thats what they get. If they want a cure for the problem and a warranty they get a new water heater. They call the shots, I take the money. Thus far I've yet to come across a bad thermostat on a heater that didn't have water leaking on it from somewhere...rarely do I replace thermostats, usually I replace the whole thing due to leaking water heater.
    Last edited: Dec 25, 2006
  10. hj

    hj Moderator & Master Plumber Staff Member

    Cave Creek, Arizona

    I check the parts and replace what is bad. The upper element operates so infrequently, in most cases, that it seldom fails unless teh bottom one has already gone bad some time ago and the heater has been operating on the upper one. Thermostats are the same way, they can fail and a shorted out element can fuse the terminals, but it is fairly rare. If they are working while you are there, they will probably continue to work.
  11. HJ --probably --dont cut it for me anymore

    if they were working before,
    they will probably still work.... ok..

    I just cant afford the gas and trip time to find out....

    I wont even fool with someone that wants to haggle with
    me over just changeing out their bottom element...only....

    I tell the customer that I am going to completely
    clean and "refurbish" their water heater from top
    to bottom with SS heavy duty elements and new
    lower and upper t stats...... that seems to sell
    the job...

    I usually leave a bucket of LIME, sedimant
    and burnt out parts behind

    depending on how far away they are it runs
    225 to 285 and they are satisfied without any return trips

    no complaints so far
  12. Randyj

    Randyj Master Plumber

    Mark... thanks for your post. I might just offer that as an option for customers.. otherwise they will be warned/told that I'll charge the same for my time to make additional trips if there are other/more malfunctions.
Similar Threads: Checking Electric
Forum Title Date
Plumbing Forum, Professional & DIY Advice Checking my plumbing - single sink to double sink Aug 8, 2014
Plumbing Forum, Professional & DIY Advice Checking on plumbing from bad contractor Aug 21, 2013
Plumbing Forum, Professional & DIY Advice Newbie from Chicago checking in Sep 10, 2009
Plumbing Forum, Professional & DIY Advice brand new electric hot water tank water only getting luke warm Feb 1, 2014
Plumbing Forum, Professional & DIY Advice Electric water heater questions Nov 25, 2013

Share This Page