Navien introduces the new Ready-Link manifold system for NPE tankless water heaters. This accessory makes manifold mounting onto the Ready-Link rack or directly to a wall simple for new multiunit installations or emergency same-day replacements, Navien explains. The kits are available in configurations of two, three and four units side-by-side, and two and four units back-to-back. Multiple Ready-Link manifold systems can be combined to support up to 16 cascading units in 30 different arrangements.