Vesta.DS premium condensing tankless water heaters are UEF (0.95), Energy Star rated, low NOx compliant and lead free. The VRP model includes a built-in Grundfos recirculation pump and SSTL 1/2-gal. buffer tank, premium-grade SSTL heat exchangers and a whisper-quiet fan design, the company states. Vesta’s VRP and VRS models are designed for residential and commercial cascade applications. Indoor installations may use 2” SCH 40 PVC venting up to 60’ or 3” up to 150’.