@stuartambient If the V2 kit pieces worked for you, the V3 will fit your device as well.Hadn't been in these parts in a while so just noticed the V3 release. Congrats! The former kits have worked so well for me. How do I know if I have the correct heater cover? The 7thHeaven site is a bit confusing and from what see there doesn't list an 18mm one. Maybe I'm wrong.
Where do I measure and what is the wrong one, if you don't mind telling me?
The heater cover that isn't compatible is the spherical one.