Alde Inline Circulation Pump 12 V The 12 V inline circulation pump has five selectable speeds, noise-reducing composite construction and integral overheat protection, with a Vortex motor. Effectively replaces the 2928-420 12 V, 2750-405 230 V and 3010-508 12 V pumps. All previous pumps. It runs off the 12 V supply from the vehicle/leisure battery or inverter, drawing 0.2–1.9 A. It can also be used with underfloor heating or large, complex heating circuits, and is suitable for all year round use.