Depends on what flue system you have and if your boiler is a THermeco Condensing models
Regulations state that flues from Class D fueled (Gas Oil) appliances MUST be at least 2-0Meters from ground level if your flue is less than 2-o metres then No youcannot use Gas Oil and must keep with class C2 Kerosene.
Why do you want to burn Gas Oil anyway, your boiler will perform much better on Kerosene Believe me I spend my life trying to convince customers to convert to Kero from Gas oil and by the way starting at the end of the year Gas oil will contain 7% Biofuel (FAME) which will require upgrading fo oil pump seals and flexible fuel hoses so yet another reason to keep with Kero!!
www.elanar.co.uk
October 2010