A flue in poor condition, combined with a boiler that's not working properly, could put you and your family in danger from carbon monoxide poisoning this can cause death or serious injury. What's the cost of replacing your boiler? We are serious about our reputation for great customer service. We could provide you with a fixed-price quote to give you an idea of the type of boiler that could be suitable for your home*** try our free quote tool today, it could take just seconds! If.