In this paper we prove that for (ru)-complete semiprime f-algebras with weak order units, A is a Banach lattice if and only if \(Orth(A)=Stab(A)=Z(A)\) . This answers a natural question posed by Wickstead in [Wójtowicz, M., Wisniewska, H.: The problem of central orthomorphisms in a class of F-lattices. Indag. Math. New Ser. 26(2), 393–403 (2015)]. The inspiration for this characterization arises from a rigorous study of finite elements in Archimedean vector lattices. Furthermore, by introducing a new class of orthomorphisms, termed pseudo-center, we affirmatively solve its related Wickstead problem.