look in your installation book , why are you doing this it sounds like you do not know what you are doing ! who is going to connect the gas and electric, how are you going to register the boiler with building control ? Do you know that if anything happens that your house insurance is void ! why risk it ?? get a gas engineer to install it for you
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.