Which kind of Boiler/which make?

[FairLadyRantALot]

Well, we have, at the moment, the most crappiest combi boiler that is just rubbish and doesn't dpo a great job , especially if asked to heat the house and give warm/hot water....
we live in a 4 bed semi detached property...not huge but not tiny neither...i.e. 2 single 2 double bedrooms, one bathroom and one downstairs bathroom (just to give you a rough idea of our environment).

Any recommendations....cheap and good would be brilliant

We had an excellent Vaillant combi, again make sure that you get a large enough size as I think combis can struggle with larger houses.
Would suggest you get some solid recommendations for local gas engineers and ask them for advice and to quote.