You will have to Bleed the oil supply and oil pump, this is best carried out by an OFTEC registered Engineer, don'y be tempted to fiddle with it as it easy to inadvertantly adjust the fuel pressure setting which will result in Trouble with a Capital "T"
There may be an Engineers sticker on the boiler alternatively go to www.oftec.org to find a competent Engineer near you.
www.elanar.co.uk, May 2009