The RCCB triping could be down to a few reasons:
*Faulty appliance (including attached flex and plug)
*Loose connections of installation
*Damaged/worn insilation of cables
*Faulty RCCB
*Moisture ingress
At the moment it is a process of elimination, so by unplugging the items that are on at night (when the trip occurs), could start to narrow the fault down to appliance, circuit and/or accessory.
Although you say your heating is not on at night I guess your boiler is still electrically connected.
The problem is to narrow down the reason behind the tripping, is that the appliances require both poles to be removed from the circuit (to prevent earth leakage via the neutral), so simply switching off at plug, light switch or some isolators does not mean you have disconnected both poles. So unplug the items that can be unplugged to start with.
The outside light which is attached to lighting circuit would require disconnecting, unless it is connected via a double pole switch(for reasons above)
Unplug/disconnect one or two items each night, then introduce them and unplug a differing one or two items and see how it goes, don't rule out the RCCB being faulty, but that will require special testing and can be considered if unplugging appliances have not resolved the issue.
*Faulty appliance (including attached flex and plug)
*Loose connections of installation
*Damaged/worn insilation of cables
*Faulty RCCB
*Moisture ingress
At the moment it is a process of elimination, so by unplugging the items that are on at night (when the trip occurs), could start to narrow the fault down to appliance, circuit and/or accessory.
Although you say your heating is not on at night I guess your boiler is still electrically connected.
The problem is to narrow down the reason behind the tripping, is that the appliances require both poles to be removed from the circuit (to prevent earth leakage via the neutral), so simply switching off at plug, light switch or some isolators does not mean you have disconnected both poles. So unplug the items that can be unplugged to start with.
The outside light which is attached to lighting circuit would require disconnecting, unless it is connected via a double pole switch(for reasons above)
Unplug/disconnect one or two items each night, then introduce them and unplug a differing one or two items and see how it goes, don't rule out the RCCB being faulty, but that will require special testing and can be considered if unplugging appliances have not resolved the issue.
