Economy 7 Storage Heater not working

Discussion in 'Electricians' Talk' started by glasgow225, Aug 6, 2013.

  1. glasgow225

    glasgow225 New Member

    Guys recently qualified Electrician and with research and bit of common sense I have found myself taking calls and subsequent work from clients on areas where I have little experience . My knowledge of Economy 7 is limited but would appreciate if anybody could support me with the diagnostic checks in priority order ? Committed to be with client at. 9.00 am tomorrow so any bullit point guidance would be fantastic . Thanks in advance
  2. seneca

    seneca Screwfix Select

    As the power will be off when you get there, (do check to make sure though!) you will need to do continuity tests on the elements and thermostat. Check for burnt/arcing connections too.
  3. Bazza-spark

    Bazza-spark Active Member

    Hi Glasgow

    Most storage heaters are fitted with thermal links that "blow" if they overheat.  They usually look like a piece of solder between 2 terminals.  If the fibreglass insulation starts to break down or gets damp and emits too much heat then the solder melts and prevents the elements from taking a charge.  If the link has gone then it's worth checking the age of the heaters as they insulation may be failing.

    Hope that helps.

    Kind regards

    BS
  4. Lectrician

    Lectrician Screwfix Select

    Most ones from the last 10 yrs or so have resettable thermal links, not one shot "solder" types.  If the thermostat fails, the overheat will operate.
  5. Bazza-spark

    Bazza-spark Active Member

    Hi Lec

    Good point, but I wasn't sure of the age of the units he is talking about.  Same principle though, if the insulation is shot you can be resetting every couple of days.

    Kind regards

    BS
  6. Lokkars Daisy

    Lokkars Daisy New Member

    What fibreglass insulation, where, ....??    if the heater gets hotter than required then the thermostat switches it off,,,,, if the thermostat fails then the bi-metal or thermal fuse switches it off
  7. Sean_ork

    Sean_ork Screwfix Select

    probably too late now but - the first thing to check is for a resettable thermal trip, resettable simply by clicking it back across

    most older style Dimplex models have them - and there's an amount of disassembly to be done to get at the switch, it's just adjacent to the main stat

    tripping is usually caused by folks covering the heater with wet washing
  8. unphased

    unphased Screwfix Select

    Usually its the stat. Just get the part no. and replace it. Regards
  9. Lokkars Daisy

    Lokkars Daisy New Member

    Often it is a failure with the wall mounted isolating switch, particulary if the heater is the largest size
  10. glasgow225

    glasgow225 New Member

  11. glasgow225

    glasgow225 New Member

  12. glasgow225

    glasgow225 New Member

    Guys did draft reply and then  lost it . Two preceding photos re elements and control panel . Firstly checked power to unit was live . Tested both elements 66ohms reading so not element . Control panel quite delicate but checked connections and any evidence of arcing but all good . Need a steer on photo 2 of where to place probes for continuity . Hard to explain but placed probes on either end of black cable and reading was 0.11ohms . Couldn't find any open circuits so put bloody bricks back in and when I turned input dial to 3 heard the thermostat click noise which wasn't happening before ? Assuming within next 24 /  48 hours will now be giving off heat and job done but still unconvinced about my accuracy of checking stat . On photo 2 where would I place probes if easy to explain and what reading should be expected ??? Sorry for long post guys and really appreciate positive supportive comments .
  13. glasgow225

    glasgow225 New Member

    Guys did draft reply and then  lost it . Two preceding photos re elements and control panel . Firstly checked power to unit was live . Tested both elements 66ohms reading so not element . Control panel quite delicate but checked connections and any evidence of arcing but all good . Need a steer on photo 2 of where to place probes for continuity . Hard to explain but placed probes on either end of black cable and reading was 0.11ohms . Couldn't find any open circuits so put bloody bricks back in and when I turned input dial to 3 heard the thermostat click noise which wasn't happening before ? Assuming within next 24 /  48 hours will now be giving off heat and job done but still unconvinced about my accuracy of checking stat . On photo 2 where would I place probes if easy to explain and what reading should be expected ??? Sorry for long post guys and really appreciate positive supportive comments .
  14. Lectrician

    Lectrician Screwfix Select

    Why did you take the bricks out!?!  No need!

    I would test across the incoming terminals at the bottom of the heater, looking for the elements resistance as you switch the stat up and down.  If open circuit, track around the circuit.

    The overheat is the browny/red block, in the pick, looking at the bottom of it.  The 'button' to press would be on top.  Test across that, the stat, and the stat to the right.

    It looks like it has been replaced at some point.
  15. wally

    wally Screwfix Select

    agree with lec about no need to take bricks out (unless an element needs replacing).     A simple way to check all elements, count how many elements, 1 = 66 ohm  2= 33 ohm  3 = 23 ohm   4 = 17 ohm or thereabouts & assuming stats & cutout are closed this could be checked without any disasembly by checking at switch or even the consumer unit if you know which circuit its on.
  16. Mr. Handyandy

    Mr. Handyandy Screwfix Select

    How did you "check power to unit was live" (assuming you didn't arrive during the 7 hours E7 time) ?

    Booster power ?

    Mr. HandyAndy - Really
  17. unphased

    unphased Screwfix Select

    Just replace the input stat like I said. Its the only likely cause.
  18. retiredsparks

    retiredsparks Member

    With all due respects unphased, the heater is dead and there are a myriad of reasons to cause this.(depending upon type and model and age.
    Time switch faulty.
    DP connection unit burnt out.
    mcb/fuse blown
    cable fault
    Off peak consumer unit main terminals burnt out.
    All elements gone.
    thermal link blown.
    overheat cutout open.
    comfort stat u/s
    ...and yes the charge stat faulty.
    I would not encourage an inexperienced sparks to fault find by replacement.
    He should take a logical approach and use test meters to confirm and locate the actual fault.
    Also, he should not be taking on work, alone,  which appears to be beyond his experience.(even tho heaters are just series resistive loads and a couple of switches)
    RS
  19. unphased

    unphased Screwfix Select

    With all due respect I said it is the only likely cause. Experience leads you to know where to start looking. The most likely cause is the input stat.

    Start with the stat and then look elsewhere. Storage heater faults are nearly always input stat. This is always accompanied by the thermal link blowing because the stat fails, elements overheat and the thermal link blows. All the other stuff on your list is highly unlikely.

    :)
  20. Lokkars Daisy

    Lokkars Daisy New Member

    the 20A switch  or  Sw Fcu is quite likely

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