by htg engineer »
Fri Jun 27, 2008 9:20 am
No, most combi's work by a plate heat exchanger transferring the heat from the sealed heating water to the Domestic Hot Water.
Alot of people think the DHW is heated directly by the flames, this is not the case with most combi's anyway, there are some exceptions (not sure about your boiler).
If the system and boiler are empty, if you open a hot tap the boiler shouldn't fire up. But I have seen some that still do. This can cause extensive damage to the boiler.
If it's going to take a couple of days for you to carry out the work, you could l eave one radiator in place, and re-pressurise system - then you can use HW as normal.
htg
