many thanks Angus not sure if i am technically minded enough to strip it but i shall have a look,dont wish to bombard you with questions but i also have a sebo bs 36 the height adjuster seems ok and ive replaced the brush strip,it is an absolute pain trying to vacuum on any carpet that has a deeper pile but ok on flat carpets,really hard work pushing on the thinker ones?maybe i need to send both units in for a service,