Help! My house is tripping.

This help sheet applies to more modern consumer units (fuse boxes) . If you have an older fuse box with rewireable uses please contact an electrician. In a domestic setting your consumer unit will most likely consist of RCD’s and MCB’s OR it will consist of RCBO’s. By following this process you will hopefully narrow the fault down to one specific circuit and hopefully even find out that it’s just a faulty appliance. If it’s not a faulty appliance at least you will have helped narrow the fault down, restored power to some of the property and potentially save some money on labour costs when an electrician does arrive.

Main Switch


  • Turn every RCD, MCB or RCBO off (which ever is applicable, see above images)
  • If you have an RCD (you may have 2) turn these back on.
  • if the RCD trips off instantly, contact your local electrician.
  • if the RCD stays on, start working your way through the MCB’s turning them on one at a time. Eventually you should get to one which trips back off. This is your faulty circuit.
  • Turn every circuit back on apart from the faulty one.
  • Go around the house checking what is working and what isn’t.
  • Refer to the section below once you have determined whether its the socket, lighting or another circuit.



    Start by going round and unplugging everything you can find that is on faulty the circuit. Be sure to check for items like your boiler or electric fire places as these can commonly be on socket circuits. Once done, try and turn the faulty circuit back on. If it trips back off, contact an electrician. If it stays on, plug everything back in one at a time until you find the faulty appliance which is tripping the circuit.


    Turn every light switch on the faulty circuit to what you think is the off position. Be sure to check for any outside lights. Once you are confident you have done this, try to turn the circuit back on. Once again, if it trips, contact an electrician. If it stays on, go round putting each light on one at a time until you find the faulty light. Once you find the faulty light you can contact an electrician to come out and have a look at it.


    Most other circuits will require an electrician to attend as these are “fixed appliances” e.g. cookers/electric showers/heating. However it will still be handy to take a note of what the circuit controls to pass on to the electrician once he arrives.