I have an old fashioned one and it also works the central heating using gas. Dealing with Waterford Stanley was a nightmare whenever I had a problem. They seem to be shopkeepers only. They just refer you to an agent for servicing/parts etc. The agent is not the best. He can give it a bit of a clean but after watching him do it, it is nothing that I really couldn't attempt myself. There was an agent who was very good but I believe he has retired now or just services main boilers.
I really dread to think what will happen if there is a problem with the central heating end of things or if I need to get parts.
If I was start off again I would get another model and separate boiler.