Thank you, crank39! I would not bother with a warranty for an adjustment, but in the even of a failed unit or something...Years ago yes once the company goes bust you are on your own but I think from memory April 2002 installers had to supply insurance backed guarantees, they supply the warranty company with their copy of the warranty whilst still trading and in the event they cease trading the warranty company pick it up from there and mirror the warranty for the rest of the duration of the policy
L.L.