Thetford Hatch Locking Door 3, 4 & 5 Service KitTechnical Specifications Features This Thetford service kit lets you repair the access door 3, 4 & 5. No instructions with this service kit, so take care when disassembling to ensure you remember the position of components e. g. springs. This parts kit includes many components of the locking latching mechanism used in the service doors but it does not include the locking barrel or push button itself. Make and Model: Thetford Service Kit for Door 3, 4