4.5 year old Raver has been misbehaving for a while... Last year's servicing Corgi mumbled about further works but never came back to test / swap components....
On Summer setting, turn on DHW and fan kicks in immediately. Can take 10second to 2 minutes for gas to fire. Gas will often cut...
get some gash pipe. chamfer then smooth the outside circumference of the pipe, then cut off ~12mm of pipe.
Push your short length of pipe into fitting, over the insert, using spare pipe to push it home over insert and thru O-ring
Withdraw spare pipe, compress collet, grasp protruding end...