I was posting this reply to a post about reversed L&N from Damocles, when the topic seemed to disappear......... in case it never comes back here's my reply. To whichever person removed it I'll just say that's not conducive to running a good forum if posts get deleted during times whan people are most likely to be using the reply. Please Post a warning that you may be doing this and give it a decent span of time before you do.
The answer;
I'll tell you what from now on I'll hang about all day just incase you happen by. I may give up work just in case
No seriously different folks will be on at different times. And it's a propper answer you need rather than the quickest.
The reversed L-N can be fatal, it's one of those no if's and buts situations. The reason why is because when you switch off the appliance at the switch it will remain live even though the circuit will of corse not be completed. If there is a fault, or a casing got damaged etc then there could be a full 230v waiting to whack someone. Also if you switch off the TV or appliance at the socket at night, it could sit there with the power back-feeding into the TV all the while.
As for what you should do. Call the installer/builder and ask to see the test results. If there are none ask why. If your contract with them said they'd do the electrical installation as part of the build, and it's faulty/potentially lethal, then you have the same come-back as you would with any other purchase of a service or product which is unsuitable for the purpose. Find out how much of the build cost was for the electrical installation, then pursue it with the Consumers Association or your Local Trading Standards people.
The solution is cheap enough in that extentions can be crimped to the existing short wires (done properly not with those dodgy squishers you see sold. Although this is a simple fix, they could have killed you and that's the bit that should worry you most.