The Navien NPE-2 series condensing tankless water heaters feature a turndown ratio up to 15:1 and multi-line control with built-in software. They also offer increased 2-inch PVC venting length up to 75 feet, a vent installation detector, expanded cascade capability, and expanded common venting capability. Like the heaters in the NPE series, these heaters have dual stainless steel heat exchangers and 1/2‑inch gas-pipe capability up to 24 feet. The NPE-2 series is available in four standard models (NPE-S2) and three advanced models (NPE-A2). Contact a distributor for pricing information.