Yes, the grey cartridge is universal... the pink cartridge is indeed designed for the combi boiler but the 609 is standard with a universal grey cartridge! So yes you have the correct cartridge, either can be used. Hope that helps, just make sure you put a flow restrictor onto the HOT inlet if your using the grey cartridge as you need need to slow the flow of water down going through the combi boiler. The pink cartridge does not need a regulator as it is inbuilt to the cartridge (actually the holes on the bio-metallic coil are small for the hot water thus producing the same effect!!!)
Gav T
February 2010