The Toyotomi Main Circuit Board, part number 20476912, is a replacement electronic control board designed for the Toyotomi OM-128HH water heater. The main circuit board manages core operating functions, including ignition control, system monitoring, and coordinated heater operation.
What’s included: one replacement main circuit board.
Installation limits: the circuit board must be installed according to the manufacturer’s service instructions. Electrical power must be disconnected before servicing, and proper handling is required to prevent static or electrical damage.
Compatibility: Compatible with the Toyotomi OM-128HH water heater model.