(206) 949-5683, Top Rated Plumber, Seattle
Page 1 of 4 1234 LastLast
Results 1 to 15 of 58

Thread: Does my water heater have a bad thermostat?

  1. #1
    DIY Member cdwz's Avatar
    Join Date
    Jul 2008
    Location
    Arlington, Virginia
    Posts
    33

    Default Does my water heater have a bad thermostat?

    We have a fairly new water heater (around 6 years old) that keeps shutting itself off. Around once a day I have to press the reset button on the high limit switch, and we have all noticed a significant increase in water temperature coming out of the taps.

    I've used a multimeter to test the thermostats and the elements, and both seem to pass the test, but maybe that doesn't mean anything. If I change the temp setting on the upper thermostat at all, the limit switch trips the second I move the dial.

    I'm pretty sure this is a bad thermostat, but I want to make sure there isn't something else that might be bad that I'm overlooking.

    Any advice is appreciated.

  2. #2
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007
    Location
    Connecticut
    Posts
    7,463

    Default

    Your problem could be caused by a bad thermostat or, elements.

    This is a safety related problem that should be addressed by a plumber ASAP!

    See this thread...
    http://www.terrylove.com/forums/showthread.php?t=22751

  3. #3
    Master Plumber nhmaster's Avatar
    Join Date
    Jul 2008
    Location
    S. Maine
    Posts
    2,039

    Default

    YES. or a bad Element. Or both.

  4. #4
    DIY Member cdwz's Avatar
    Join Date
    Jul 2008
    Location
    Arlington, Virginia
    Posts
    33

    Default

    Well I tested the elements using a multimeter, and they have no resistance when tested through them (one tester lead on each screw of the element) and infinite resistance when tested to the mounting bolt. I know the latter of those two is correct, but it seems like they should have at least some resistance.

  5. #5
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007
    Location
    Connecticut
    Posts
    7,463

    Default

    Your meter may not be accurate enough to dicern the resistance.
    Depending on the wattage of the element it may be around 12 -13 ohms.

  6. #6
    DIY Member cdwz's Avatar
    Join Date
    Jul 2008
    Location
    Arlington, Virginia
    Posts
    33

    Default

    Quote Originally Posted by Redwood View Post
    Your meter may not be accurate enough to dicern the resistance.
    Depending on the wattage of the element it may be around 12 -13 ohms.
    Ahh, good point. It's a cheap, 15-buck analog meter.

    I'll replace the upper thermostat since that's the most likely culprit. When I press the reset button on the upper t-stat, it's always blazing hot, and this element is not even supposed to kick in very often.

    Thanks for the help.

  7. #7
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007
    Location
    Connecticut
    Posts
    7,463

    Default

    Did you check the link to the other thread I provided above.
    As I stated this is a safety related problem and at this moment you are relying on the reset and the T&P to prevent the same thing from happening at your house.

    I would highly recommend calling a plumber to diagnose and correct this problem.

  8. #8
    TROJAN WORLDWIDE SALES RP MACPLUMB 777's Avatar
    Join Date
    Aug 2007
    Location
    Houston, Texas, United States
    Posts
    631
    Blog Entries
    1

    Default Water Heater Explosion ! ! Update ! !

    No Just A Bad Plumber Who Doe's Not Know What To Check For ! !


    That Said One Of Your Elements Has A Small Bad Spot, Like A Piece Of Fruit,

    One Side Always Has 110 V. To It
    The Other Side Is The Switch Leg, With A Bad Spot On Element It Goes To Ground Against The Inside Of The Tank Which Means It Is Constant Low Heating
    During Periods Of Not Using Hot Water It Trips The Overheat Limit
    Switch Thats Why You Get Extra Hot Water Out The Faucets

    MACPLUMB 777

    E-MAIL
    JERRYMAC@TROJANWORLDWIDE.COM


    35 YEAR MASTER PLUMBER, HEATING, ELECTRIC, DRAINS, FIRE SPRINKLERS, WATER HEATER
    AND BOILERS SINCE JAN, 1989

    281-706-1631 7 DYS A WEEK SALES AND TECH. SUPPORT
    Trojan Worldwide Web Site


     



  9. #9
    TROJAN WORLDWIDE SALES RP MACPLUMB 777's Avatar
    Join Date
    Aug 2007
    Location
    Houston, Texas, United States
    Posts
    631
    Blog Entries
    1

    Default Water Heater Explosion ! ! Update ! !

    You Should Look At The Post 5-4-3-2-1- Lift Off Before Risking You, Your Family, And Home On D I Y Type Repairs As Opposed To Calling A Lic. Plumbing Contractor To Do The Work ! ! !


    If As You Posted You Have Open Legs Across Both Sides Of Element Then It's Is Burnt Out, In Which Case You Would Not Have Any Hot Water ! ! !

    MACPLUMB 777

    E-MAIL
    JERRYMAC@TROJANWORLDWIDE.COM


    35 YEAR MASTER PLUMBER, HEATING, ELECTRIC, DRAINS, FIRE SPRINKLERS, WATER HEATER
    AND BOILERS SINCE JAN, 1989

    281-706-1631 7 DYS A WEEK SALES AND TECH. SUPPORT
    Trojan Worldwide Web Site


     



  10. #10
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007
    Location
    Connecticut
    Posts
    7,463

    Default

    Quote Originally Posted by MACPLUMB 777 View Post
    You Should Look At The Post 5-4-3-2-1- Lift Off Before Risking You, Your Family, And Home On D I Y Type Repairs As Opposed To Calling A Lic. Plumbing Contractor To Do The Work ! ! !
    Um Jerry that is the thread I linked.

    Man that house looked like it sneezed!

  11. #11
    DIY Member cdwz's Avatar
    Join Date
    Jul 2008
    Location
    Arlington, Virginia
    Posts
    33

    Default

    I don't think I have to worry about an electric water heater exploding. A gas one maybe. Thanks for the link though.

    The breaker's off for what it's worth. We can live without hot water until I get the problem fixed. The showers are luke warm without it because it's 140 degrees plus in the crawlspace where the pipes go. Just gotta shut off the tap during suds up as not to run out of the crawlspace-heated stuff.

    The one in the story is electric, and there are other video's done in a farm field with an electric heater also. It's very easy to rig an electric water heater to rocket up and through a structure like a house. Terry
    Last edited by Terry; 08-19-2008 at 11:07 PM.

  12. #12
    Master Plumber Redwood's Avatar
    Join Date
    Dec 2007
    Location
    Connecticut
    Posts
    7,463

    Default

    It doesn't matter how it heats up...
    The end result is the same...
    All that is betweem you and boom, is that red reset button and a t&P valve.
    The effects of thermal expansion and steam pressure do not dicern the method of heating.

  13. #13
    Moderator & Master Plumber hj's Avatar
    Join Date
    Aug 2004
    Location
    Cave Creek, Arizona
    Posts
    25,659

    Default heater

    I do not measure resistance of the element. I test if it should, or should not, be heating and then if it is. The reset button is independent of the thermostat setting, so if your description is correct it could be a bad thermostat.

  14. #14
    Plunger/TurdPuncher kingsotall's Avatar
    Join Date
    Aug 2008
    Location
    Flagstaff, AZ Sitting on an upside down 5 gallon bucket next to the GO 68HD
    Posts
    1,260

    Default

    Quote Originally Posted by cdwz View Post
    I don't think I have to worry about an electric water heater exploding. A gas one maybe. Thanks for the link though.


    Sounds like no matter what he doesn't need a plumber. Remember, these folks try to lead you in the right direction. If it's DIY do-able then they say so. If they recommend a pro, I'd listen to 'em.

  15. #15
    Licensed Grump GrumpyPlumber's Avatar
    Join Date
    Jun 2007
    Location
    Licensed Grump
    Posts
    1,404

    Default

    No insult intended to the homeowner here, but in lieu of the incident in Phoenix I wouldn't advise anyone to so much as adjust the temperature on an electric water heater.
    On a 6 yr old water heater, if that T&P isn't functioning properly and the breaker is already tripping on the heater, I'd strongly suggest he get a pro.
    "The biggest regrets we have in life are the chances we never took."

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •