Apologies if you have done this suject to death but I've done the search and cannot find any previous posts. My son has just bought a large three bed semi which requires gutting. The existing CH boiler is an old back boiler which will need replacing in order to fit the kitchen. We are planning to install a wall mounted boiler concealed within a kitchen cupboard -gas connections and commisioning to be done by qualified engineer. The question is whether to go for a combi or open vent boiler. Existing cold storage tanks, cylinder and immersion heater are all in good nick. As I've yet to come across an electric shower that is anywhere near as good as my gravity fed unit, I'm leaning towards a new open vent system. Am I missing anything obvious? Thanks!