Why do new houses

[Tibbot]

what if there is no hot water in the tank will the boiler also heat the water on demand?

if we was to replace the boiler would it just be a simple boiler swap with the rest of the system staying the same?

This is why I wrote that.

Firstly you ask if a boiler can heat water on demand through a STORED water cylinder full of cold water.

Then ask if you can change from a combi system to a traditional system (which would require a HW store) with just a boiler swap.

 

[Tibbot]

Sorry, I see your new house doesn't have a combi, so I take that bit back.