I have just switched each individual switch off and the off switch has now stayed on. 
 

Sockets Downstairs 

Sockets Upstairs 

Lights Downstairs 

Lights Upstairs 

I turned each one back on individually. It is the socket downstairs switch that is tripping. So I have the other three working now. 

Is there a way to find out which socket downstairs could be causing the electricity to trip?

 Thanks 

I assume that you have made absolutely sure that nothing is still plugged into a downstair socket?
ie, checked any sockets in cupboards, under the stairs etc. Unplugged the fridge/freezer, microwave etc.
(Personally I’d also unplug everything upstairs too, particularly any sockets near the stairs themselves. It’s possible that one or more is actually on the downstairs circuit).

If every socket in the house is empty and it’s still tripping then there is a wiring fault somewhere on the installation and you will need a qualified electrician to trace and repair it.
They have tools/meters that are made for the job of tracing faults.

Sudden trips are usually caused by an appliance fault. (Christmas lights in particular at this time of year).
Sudden wiring installation faults are much more unusual but do happen, something could have come loose in a socket or junction box and shorted, water could have leaked behind the walls and be causing a short, even rodents chewing through wiring insulation and causing a short is known to happen.

Suggest you do this but your safety is important at all times so the advice is to call a qualified electrician. I think it is more likey to be something that is plugged in rather than the ring final circuit itself.

If you are sure of your safety, for each socket that has something plugged in switch off that socket and try and reset the downstairs sockets breaker. That should identify the equipment at fault. Unplug that equipment and either dispose of it or get it tested / repaired by a qualified person.

If you have switched off all the sockets and the breaker still won't reset then it is likely to be a fault in the downstairs ring final wiring and it must be tested.

AGAIN, only do this if you are sure of your safety at all times and preferably with someone else monitoring what you are doing. Please stay safe.

Peter

Just thought I’d mention that you’re totally welcome here too. The OVO Forum is open to everyone regardless of supplier - the only snag is that if you’re not with OVO then we can’t pull off certain OVO-Specific magic tricks but otherwise you’re good. :)