We moved into our house 7 months ago. It has a gloworm back boiler at the moment (it's old but not sure how old). Having a new central heating system and all new rads and pipework. It's a fairly large detached house, 2 double bedrooms and 1 large double bedroom, 1 bathroom and a downstairs wc. We have 10 rads at the moment but will need 11. The immersion and water tank are in the bathroom but if we keep them we would create more room in the bathroom and move the immersion to one of the bedrooms and the water tank to the loft. I've spent ages on the internet looking at different boilers and systems but cannot decide. We've had quotes for combi's, unvented cylinders and heat only boilers, the quotes being from £2500 to £6000 from various plumbers, the combi being the cheapest. We've decided which plumber we are having (has a very good reputation). Would like advice on what people think would be best system and which boiler to have.