The case of the mysterious Immersion heaters....

Discussion in 'Electricians' Talk' started by sparky Si-Fi, Jan 30, 2004.

  1. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Evenin'!

    Just got back from a call out about two IH elements in a tank suspected of 'Gone' by the owner,due to being on and no hot water coming through

    Supply to tank,both ok,tested elements both ok,fuse/cb's ok

    Last but not least,got him to open the meter box while I put both IH elements ON.............

    Meter did what I suspected,belted around when ON virtually stopped when switched off,have not heard any more tonight from Him.............

    Whats the collectives verdict?
     
  2. Damocles

    Damocles New Member

    tank was hot? maybe he's absent minded or has a burglar using all the hot water. plumbing problem? Is there a thermostatic valve which mixes cold water with the hot to limit the tap temperature, and its failed?
     
  3. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    tank was hot? maybe he's absent minded or has a
    burglar using all the hot water. plumbing problem? Is
    there a thermostatic valve which mixes cold water
    with the hot to limit the tap temperature, and its
    failed?

    I aint no plumber dam.but all I can say is what I found,there's obviously a demand when the IH's are ON,so waters heating up,either that or he is heating next doors water...LOL
     
  4. Damocles

    Damocles New Member

    Magical self-resetting breaker? is that technically possible if it blew up somehow and was tripping out?
     
  5. Damocles

    Damocles New Member

    As I said, was the tank hot? if so, then the water heater works and its plumbing. if not, then either its electric or someone has sneaked in and added a pipe to next door. Would need to wait a while to see if it did get hot. Like I just said, could a faulty breaker get hot after 10 minutes or so, not trip out properly and then reset when it cooled? Theyre designed to fail safe, but everything goes wrong sometime.
     
  6. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Sorry mate,did not know if tank was getting hot,but could hear elements warming up inside,hung about for 10 mins or so and meter still belting round, so as you say reckon it might be a plumbing prob,or else someone is having a crafty shower just at the time I switch on the IH's.........he aint phoned back though so might be ok.
     
  7. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    sorry just to add,unknown also about the mysterious breaker getting hot,but both DP switch with neons were on all the time whilst IH's energized,so could dismiss that.
     
  8. bilco

    bilco New Member

    Hi sifi

    He clealy wanted someone younger or something :eek:
     
  9. Damocles

    Damocles New Member

    wasn't a candid camera scam? It was working while you were there, so could only be something which would take longer than 10 minutes to show. Very unlikely elements or switches as there's two, intermittent thermal fault on cable connection or that breaker again.
     
  10. The Trician

    The Trician New Member

    Interesting one this:)
    Don't know if the meter was reading the heaters or another load? If the water was not getting hot, then its a case of checking the stat(s) for correct operation, or you may have a Neutral burnt off somewhere? What did you get when you checked the heater terminals with your trusty multimeter? Continuity from the incoming L to N thru' the heater via the stat? What about continuity of the Neutral back to the supply? Were the heaters wired in series? Just a few things to check:)
    Let us know how you get on.
     
  11. ban-all-sheds

    ban-all-sheds New Member

    And even if there isn't a hidden camera, don't **** into the CU....
     
  12. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Interesting one this:)
    Don't know if the meter was reading the heaters or
    another load? If the water was not getting hot, then
    its a case of checking the stat(s) for correct
    operation, or you may have a Neutral burnt off
    somewhere? What did you get when you checked the
    heater terminals with your trusty multimeter?
    Continuity from the incoming L to N thru' the heater
    via the stat? What about continuity of the Neutral
    back to the supply? Were the heaters wired in series?
    Just a few things to check:)
    Let us know how you get on.


    Hello again trician,

    meter definitely reading IH's,no other loads on,cont test on both elements 'Beep' or very low (even stuck an insulation test on them both 'bout .15megs each),both IH elements wired in parrelel with separate breakers back at the board,still, no word since from him?
     
  13. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    oh yes forgot to add,neutral back to the cu fine and supplly thru stat.running out of ideas now....

    answers/other suggestions on a postcard please.....:)
     
  14. The Trician

    The Trician New Member

    If you don't hear from him again, you've cracked it!
    The job's a good'un! If the phone does ring again, try dropping a clip-on ammeter on the supply L+N just to see if the things are actually dragging any current. Worth a shot:)
     
  15. BRIGHTSPARK

    BRIGHTSPARK Guest

    WAS THERE ANY WATER IN THE CYLINDER?
     
  16. Sam Dingle

    Sam Dingle New Member

    What about if the element was fured up so bad that heat was being directly transfered to the stat and so it cuts out after a period of time but isn't on long enough to heat the water.
     
  17. The Trician

    The Trician New Member

    Not an unreasonable assumption this. Not sure if it's a tank with a lid, or a copper cylinder, but if it's a tank, you should be able to see the heater elements.
    Worth a look...
     
  18. bilco

    bilco New Member

    The heat insulating qualities of the scale would prob ballance out that effect...usual thing is the element breaking and continuing to heat the water at a lower rate while conducting thro the water. But not on 2 at the same time.

    I remember one time a woman asked me to climb through her bedroom window and open the door, because it was stuck from the inside...I got in there (no not that) and the door was totally free?!?

    Still think he wanted a young un ;)
     
  19. leeds spark

    leeds spark New Member

    i have come accross this scenario before,and the cause was a split element,again,meter spun,but this was electric running through the water and back to earth,the resistance of the water stopping the breaker tripping by passing roughly the same current as a normal heater.This also makes the hydrogen/oxygen in the water separate which also sounds like normal i/h operation.Oh,btw,a split element will also warm the water very slightly,and so may not show up for a day or so.Try feeding element directly eg no thermostat)through an rcd for a few seconds,if it trips,you've got a split element.
     
  20. try using an insultion tester. it will reveal if the element has split as you will get a low reading to earth.
     

Share This Page