Thanks for the replies, i've taken some photos to see if it helps.
Downstairs switch
This was originally a double switch but one of the switches did nothing so I thought i would change to single switch.
Correction from first post - the Red wire that wasn't connected was the one from...
I have just been replacing some light switches - nice simple task I thought until it came to replacing the two way light switch for the landing.
In the original switch, the red from the lighting circuit was not connected to anything and a separate piece of red wire was connecting two of the...