I am about to install a Hot Water Towel Rail supplied by a Pressurised GCH System (I Think - there is no DHW Cylander or F&E Tank and its in a first floor flat) Central Heating System heated by a Combi Boiler.
Firstly is it ok to drain this system once the boiler has been switched off electrically to commence work?
And if so, will I just top it up using the metal braid hose below the boiler (having added an inhibitor into one of the radiators) to take it back up to it's original pressure (approx 1 - 1.5 bar)?
Do I need to flush the whole system once I have fitted the Towel Rail or could I get away with this if I use Compression Fittings below the floorboard to connnect the Flow and Return so it looks better and I wont then have any Flux etc in the system from soldering capillary fittings.
I am a bit worried about potential swarf inside the towel rail from the manufacture process contaminating the existing CH System. Or is this an old wifes tale?