1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Crazy RCD tripping

Discussion in 'Electrics UK' started by Toddzbox, 28 Nov 2019.

  1. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Here's my problem: I hope I've isolated the appliance that causes the right hand side of our consumer unit RCD to trip.
    If we leave the dishwasher on alone we can come home to find the CU has tripped. I flip off the offending circuit (washing machine, tumble dryer, heating boiler, dishwasher) and can the the rest back on.
    To me, that's the easy bit! What I can't understand that after a freezing cold evening and night I can get up early next morning and can then, and only then flip the offending circuit back on, the heating comes on and all's well again?
    I do take all the plugs out of the appropriate sockets when this happens, the boiler man has serviced and come back to check the boiler.
    It has been about 9 days since the last time it happened - another reason I can't work out what to do next.
    Any suggestions on how to proceed? Obviously call out a domestic electrician but we're oldish and poor and this seems to be one of those expensive to find problems.
     
  2. Sponsored Links
  3. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    43,130
    Thanks Received:
    2,744
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Welcome to the forum.

    Are you saying that if you don't switch off that circuit, you cannot (immediately) re-set the RCD? If so, what happens if you unplug the dishwasher - can you then re-sent the RCD?

    Well, if the cause of the fault is intermittent (e.g. water getting into the electrics of your dishwasher), then that problem would probably eventually go away (e.g. due to the water ingress 'drying out').

    As you have surmised, finding the cause of this sort of problem can sometimes be difficult/tedious, not the least because of its intermittent nature. If you have good reason to suspect the dishwasher, one think you could do (if you're prepared to do without the DW, and get your Marigolds out!) would be to leave the dishwasher unplugged for a good while and see if any further RCD trips occur.

    Kind Regards, John
     
  4. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    That's food for thank you. Not being keen on marigolds we have been using the dishwasher via an extension lead. This generally works - certainly better than plugged into the behind the kitchen unit near the kitchen sink socket! I shall have good think and root around.
     
  5. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    43,130
    Thanks Received:
    2,744
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    If you are successfully using it (without trips) (and continue to be able to use it without trips) by running it via an extension lead from another RCD-protected circuit, then that would obviously let the dishwasher off the hook as being the culprit.

    Kind Regards, John
     
  6. AndyPRK

    AndyPRK

    Joined:
    4 Jan 2009
    Messages:
    4,752
    Thanks Received:
    431
    Location:
    Herefordshire
    Country:
    United Kingdom
    is the boiler on the same circuit/mcb as the boiler ?
     
  7. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Well it's gone twice using the lead, but I take your point, and check my facts.
    The only thing running when we left today was the dishwasher. But you're right.
     
  8. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    If you meant to say Dishwasher Andy, yes. As a non electrician we haven't ever had the tumble drier, dishwasher, washing machine and heating on at the same time cos it seems too much power for one circuit to me.
     
  9. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    43,130
    Thanks Received:
    2,744
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Even if it were, that would, of course, not be a reason for an RCD to trip.

    The 'heating' (if you mean boiler + pump etc.) will use little electricity. As for the rest, it's by no means unknown for people to have tumbler dryer, dishwasher and washing machine all running from the same circuit simultaneously, without a problem. In fact, the average consumption of that lot is less than you would probably think. Depending upon the type, the dryer might draw high current continuously, but the DW and WM will only represent a high load whilst heating water - that's only for a relatively short period of time, and often not even simultaneously for the two machines.

    Kind Regards, John
     
  10. Sponsored Links
  11. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    43,130
    Thanks Received:
    2,744
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Was it plugged into a circuit (via the extension lead) which was protected by the same RCD as it was previously tripping (i.e. it was the same RCD that tripped). If so, would it be possible for you to plug the extension into a circuit protected by the 'other' RCD (presuming, that is, that you have two RCDs!)?

    Kind Regards, John
     
  12. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    The consumer unit has two sides both populated by what I would have called in the old days fuses. The part of the unit to the right is the one causing the RCD to trip.
    When using the dishwasher on a lead, it's on a different circuit with another RCD which doesn't trip.
    Sorry if I confused you.
     
  13. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    43,130
    Thanks Received:
    2,744
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    I'm afraid that I am still a bit confused :)

    When you say "...another RCD which doesn't trip" do you mean "...another RCD which usually doesn't trip"? (i.e. which previously was not tripping) - and, if so, when you wrote that "...it's gone twice using the lead...", did you mean that the RCD which doesn't usually trip did trip (twice) when you plugged the DW (using an extension) into a circuit that was protected by it?

    If that is what you meant, then that would surely more-or-less prove that the dishwasher was the guilty party, and therefore needed to be repaired or replaced, wouldn't it?

    Kind Regards, John
     
  14. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    To save confusing you again, your previous answer stands in that it can't be the dishwasher.
    So I've now unplugged everything I can, except the boiler which is wired into a fused plate.
     
  15. JohnW2

    JohnW2

    Joined:
    28 Jan 2011
    Messages:
    43,130
    Thanks Received:
    2,744
    Location:
    Buckinghamshire
    Country:
    United Kingdom
    Well, as you might imagine, I'm still a bit confused. However ...
    Fair enough.

    If you still get trips, they obviously would have to be due to something you couldn't unplug (like boiler etc.), or even the wiring (including things like 'water in a junction box') - in which case you would probably need professional assistance.

    If you get no trips with everything else turned off, then you'll just have to start plugging things back in, one at a time, in the hope that that will identify the culprit.

    Kind Regards, John
     
  16. Toddzbox

    Toddzbox

    Joined:
    28 Nov 2019
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks for all your help John you've helped me move away from one culprit and given me a few more ideas to chase up. Stephen OK
     
  17. DIYnot Local

    DIYnot Local

    Joined:
    3 Sep 2019
    Country:
    United Kingdom

    If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

    Select the supplier or trade you require, enter your location to begin your search.


    Are you a trade or supplier? You can create your listing free at DIYnot Local

     
Sponsored Links
Loading...

Share This Page