Hi all - this isn't a question - it's an answer. However it answers so many questions here I thought it would be best to put it in like this. Hopefully that doesnt cause any problems!
If you need a user manual for your sime boiler go to:
www.sime.ltd.uk
There are downloadable PDFs of manuals for almost everything there. Takes a bit of hunting to find the right one (mine is a Friendly Format 80 boiler but I had to go to the Format C boiler manual to find how to work it!)
But hey - it works!! Happy reading for those that need it.
Thanks to your info i saved a good 50 quid or more from an engineer!. Downloaded the relevant pdf, and my boiler was back up to pressure and a could have a nice hot bath!.
Appreciate your help, Chris