Would my combi boiler heat water if I drained heating system?

I have a Vaillant Turbo Max Combi Boiler and a sealed heating system. I want to add a radiator and renew a couple of others which are not very efficient any more. For this I need to drain the heating system to work on the plumbing of additional radiator and exchange of others. But in the meantime I need the combi to continue to supply hot water. Will my boiler continue to work?
Noni.