Rinnai 1500i Sensor Wiring Harness The Rinnai 1500i Sensor Wiring Harness is a genuine, made-to-last replacement part specifically designed for the Rinnai HDC1500i (plus the HDC1600i models it's compatible with) commercial continuous flow water heaters. This is the wiring harness you need to make sure your system gets accurate temperature readings from its sensors and the main control board - all of which is vital if you want the thing to run smoothly, efficiently and safely. Over time, wiring harnesses wear out, they get hot, and the connections can become worn. Replacing the harness with a genuine Rinnai one puts an end to signal loss and helps ensure the combustion and temperature control in your system stays spot on. Quality-checked to Rinnai's own exacting standards, this replacement harness fits like a glove and will last the distance i