The Rinnai M6J-1-3 Water Heater By-Pass Servo Assembly 403V regulates water flow through the designated bypass circuit in a compatible water heater. This assembly uses an electrically operated servo mechanism to adjust the bypass valve according to commands from the heater’s control system. Its operation supports proper water flow management and contributes to the unit’s intended temp... https://www.hnkparts.com/m6j-1-3-rennai-by-pass-servo-assembly-403-v