Keep replacing top thermostat. Works for a day. Wiring right?

Discussion in 'Water Heater Forum, Tanks' started by Greg Wmson, Jan 23, 2012.

  1. Greg Wmson

    Greg Wmson New Member

    Messages:
    2
    Location:
    St. Petersburg, Florida
    I'm looking at this..

    Water-heater-wiring photbucket.jpg
    And mine is wired like this.
    photo shot.jpg

    It appears my T2 and T4 are reversed. Would this cause my thermostat to stop working?

    Have I damaged my thermostat or will reversing the wires fix my problems?

    Was concerned because this new thermostat was not exactly like the original Rudd one and had my neighbor an electrician came and help me and he wired it like this. I woke up this morning, had no hot water, put a voltmeter on it and it was pretty much dead,
    Replaced it this afternoon myself just as he had it, and we had hot water.. tonight.. same thing, no hot water. I have replaced all the elements and both thermostats, wifes gonna wake up angry when she takes cold shower in am.. any help is really appreciate. Thank you.
    Last edited: Jan 23, 2012
  2. Terry

    Terry Administrator Staff Member

    Messages:
    15,423
    Location:
    Bothell, Washington
    I would wire it according to the diagram if they supplied one for you.

  3. Hackney plumbing

    Hackney plumbing Homeowner

    Messages:
    1,174
    Location:
    Alabama
    Make sure your thermostats fit tight against the tank after you corrrect the wiring.
  4. kevink1955

    kevink1955 Member

    Messages:
    33
    Location:
    L.I. New York
    Using the photo you provided the heater would have run first on the lower element then once the upper thermostat reached temp it would have switched to the upper elememt but the only control on the upper would be the manual reset high limit.

    Rewire it the way the diagram shows then push the red reset button on the upper stat, I do not think you could blow anything electrical the way you have it wired but it will trip the manual reset high limit.

    The way it should work is when you first power it up cold the upper stat powers the upper element.
    Once the top of the tank comes up to temp the upper stat switches the upper element off and powers up the wires to the lower stat.
    The lower element then heats till the lower stat reaches temp and turns off the lower element.

    Once the heater shuts off, drawing a few galons of water will cause only the lower element to cycle. If you draw a large amount of water the top thermostat will switch removing power from the lower stat and applying power to the upper element.

    From a cold tank you should always have the top element on first so the tank can provide hot water faster.
  5. Greg Wmson

    Greg Wmson New Member

    Messages:
    2
    Location:
    St. Petersburg, Florida
    Just wanted to follow up and say, Thanks everyone so much, I did just that and its working fine now.
    I checked my voltages off and on throughout the day and the explanation you gave, my voltmeter and the scalding hot water told me everything was working perfectly now..
    Again, Thank you very much.
  6. kevink1955

    kevink1955 Member

    Messages:
    33
    Location:
    L.I. New York
    Glad it worked out now back both stats down to 120 so it's not scalding. Unless you have a tempering valve 120 is the max you should set a residental heater to.
  7. Jerome2877

    Jerome2877 In the Trades

    Messages:
    397
    Location:
    BC
    No

    A 1996 report titled, "Risk Factors for Domestic Acquisition of Legionnaires Disease," concluded from case studies in 15 hospitals that "a portion of sporadic cases of Legionnaires' Disease may be residentially acquired and are associated with domestic potable water." This study agreed with previous reports that found 6% of the homes studied had Legionella pneumophilla. The Legionella exist in the biofilm on the inside of pipes. A report issued in June of 2000 by the State of Maryland supports this position and investigated the presence of Legionella in the hot water distribution systems in hospitals and institutions. The report hypothesized that the source of Legionella was the public/municipal water system. Legionella grows rapidly between 77 degrees F and 108 degrees F. The solution for preventing the Legionella is heating the water to 140 degrees F.
  8. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,334
    Location:
    New England
    Feel free to have your TANK temp whatever, but the OUTLET should be tempered for safety purposes. Where I live, they require a tempering valve...but, you can set it to what you want. It is a rare house that needs 140-degree water at a fixture.
  9. DonL

    DonL Jack of all trades Master of one

    Messages:
    4,517
    Location:
    Houston, TX

    What don't kill You makes You stronger...

    125°F is recommended, as safe. For the tank too.
  10. kevink1955

    kevink1955 Member

    Messages:
    33
    Location:
    L.I. New York
    Thanks for the info on Legionnaires' Disease, I run my heater around 150 but temper it outside the heater.

    When I replace my 50 gal with 75 or 80 I am going to run it cooler as I feel it stresses the tank runing it so hot, only reason it's so hot right now is my jetted tub needs it that high to allow the undersized heater to fill it with bath temprature water.

    Around here almost no one has tempering valves on their heaters and most are set at 120 to 130 to prevent scalding
  11. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,272
    Location:
    Cave Creek, Arizona
    Please be aware, that when you replace an upper thermostat that you follow the wiring diagram that comes with it, because there are thermostats with T2 and T4 reversed. If you install one of these the way the original one was, you will have the same problem this person did.
    Last edited by a moderator: Jan 27, 2012
  12. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    The most dangerous thing in that water heater was driving to the hardware store. As long as you are not a leggionaire, 120' is a acceptable risk in life.

    A ride on a packed subway is likely the greatest risk to life. You can taste the virus's in your mouth when you come off the mountain after a few months.
  13. rap

    rap New Member

    Messages:
    63
    Location:
    california
    Anyone know of any instances where a residential water system was caused with Legionnaires disease?
    If there are such cases, then is there any info. ref. the w/h temp?
  14. rap

    rap New Member

    Messages:
    63
    Location:
    california
    In the above thread i meant, of course, "has caused Legionnaires."

    As a matter of interest, perhaps, warm water sitting in rarely used, or abandoned without being capped off, supplies for furnace humudifier's or coolers ( mentioned in the post above about thermostats ) could also, potentially, create Legionnaires conditions?
  15. Hackney plumbing

    Hackney plumbing Homeowner

    Messages:
    1,174
    Location:
    Alabama
    In Las Vegas the new Aria Hotel and casino was hit with an outbreak of legionaires disease and found evidence of it coming from the hot water distribution system.

    I believe it was in 2010 or 2011
  16. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    http://www.arialasvegas.com/facts/
  17. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    diseases and bankruptcy from casino's is a simple proof of natural selection at work.
Similar Threads: Keep replacing
Forum Title Date
Water Heater Forum, Tanks Di electric union keeps corroding Dec 15, 2014
Water Heater Forum, Tanks Tagaki TK2 keeps tripping the GFCI, help Sep 1, 2014
Water Heater Forum, Tanks Upgrading Propane Water Heater to Electric, can I keep propane as backup? Mar 17, 2013
Water Heater Forum, Tanks how to remove keep turning Watts connecting hose? Sep 1, 2012
Water Heater Forum, Tanks AO Smith FPS 50 Powervent Water Heater: Burner won't stay lit, blower keeps running Nov 26, 2011

Share This Page