If you don't have a manual ring SIME direct Tel. 0870 9911114 - Fax 0870 9911115
www.sime.ltd.uk - e-mail: enquiries@sime.ltd.uk and speak to Technical Support who may be able to help or you could email them at this address and they can at least email you the manual which if you haven't already got it, which will help your plumber to mend the boiler! Hope this helps. They were very helpful to me when i rang this morning.
Jane
April 2008