Uponor (Wirsbo) A3030524 – Two-Wire Thermal Actuator For Stainless-Steel Manifold – The new two-wire Thermal Actuator for Stainless-steel Manifolds (A3030524) completes Uponor’s actuator offering for radiant heating and cooling manifolds. Features: Two-wire, slow-opening, 24VAC Mounts directly to Uponor’s Stainless-steel Manifolds Provides individual loop flow control on a multi-zoned manifold (manifold serving more than one zone)