A lamp connector assembly for an ultraviolet (UV) water treatment vessel includes a sealing collar configured to connect to a headplate of the UV treatment vessel. The sealing collar includes a first lamp collar interlock feature. A lamp collar is configured to releasably connect to the sealing collar. A release member is moveably connected to the lamp collar. The release member has a locked configuration that engages the first lamp interlock feature to prevent movement of the lamp collar relative to the sealing collar and an unlocked configuration that disengages the first lamp interlock feature to allow movement of the lamp collar relative to the sealing collar.