Any tips for cleaning the feed filter inside the water tank of our Model 607, it’s probably stuck in place to reluctant to try unscrewing it, any chemical solutions that would do the job?

Filled filter pocket with hot Fernox DS 3 solution in the end and left it in for about 12 hours, it cleaned the filter pretty thoroughly. Removing most of the deposits in the pocket opened a tiny drip in one of the soldered seams too, expect this will eventually bung up with feed treat deposit.

Good stuff that DS 3, great for cleaning boilers of lime scale.