Electrical. Problem

[fever28]

I will be calling electrician!
But. What's you opinion on this,
Fairly large house , the main fuse box keeps tripping, no individual fuse goes,
But I have to turn all off. Reset then back up one at a time. More often that not it will go again while doing this, but it's not always the same individual fuse that makes it go again.

Wait an hour, and they all flip up. And we have it all working.

We do have lots of extensions, so the two plug sockets in living room have 6 devices plugged in etc.

[fever28]

Hi, water boiler was replaced last year.
Big stuff, oven, boilers, dishwasher etc all work fine, never an issue to turn trip back on.
Have gone through all the plugged in appliances and they all work fine, down stairs but some trip. Upstairs

[fever28]

update
electrcian was here all day, cause not found.
old RCD was moved so the two main circuits that trip are on there own RCD
still flips for everything else though.
ie can turn on things like shower and oven, but when you turn them to high/hot it then trips.
a light. can trip it, but go unplugs a few things and i can turn on the last device that triped it.

is there any thing i can check or do my self to locate fault? electricain was good an worked hard but his hourley rate is quite high for just taking sockets off and tightning screws etc.