Sorry, can't help with camping shop - unless Roy's of Wroxham have one! If they cannot get a new filter, they can still use the pump if they take out the old one, remove the white filter part and screw back the cap. Water won't be filtered but the pump will still work.
Try Jeckells Chandlers in Wroxham - the filters may also be used in boats.
Failing that it's Drayton Caravans, Heigham St, Norwich or Norwich Camping in Blofield.
A day of all things motorhome and campervan. The show is held both in the main indoor arena and across the grounds. Catering, hot drinks and food options are available. Easy access to the site and free parking included. Win one of five pairs of day tickets