Mark, if you 'just want central heating' then find a gsr, well liked local installer and trust them. If you want to do some research and form an opinion
then ask away. If price is an over riding issue beware the cheapest boilers and installers can be problematic. Tell us
type of house, age, no of rooms, no of bathrooms, oil, nat gas,lpg, solar electric, no of people in house or flat, lifestyle of the building, future extensions. This is what an installer will consider unless you opt for a package.
Rob Foster aka centralheatking