I have a 4 bed house with 2 bathrooms. Its a property that has been let to tennants. Its time for me to replace the boiler. At present I have a Potterton floor standing boiler (in kitchen ground floor) and an ariston cylinder (in bathroom 1st floor). The system is 7 years old. Recently had problem with water discharging into tundish. When I got plumber to check they said it is repairable, maybe valve change and check/correct pressure. But overall, and I agree with him, the state of the bathroom (recently had leak by the sink) and vinyl floor etc etc, suggested that I renew the whole set up. Its time to refurbish. So, new boiler also in the bathroom with cylinder. complete overhaul of the bathroom and remove make good the kitchen (where the current boiler is). What would be the best boiler? Would a combi boiler suffice without the tank?