The Ideal part is located within the printed circuit board section. The printed circuit board is the control centre of the appliance. It controls and monitors every process that occurs via the sensors, switches and thermostats. It also enforces the safety parameters, making sure that the boiler ceases to function if any of the internal readings point to a fault in the operation. The printed circuit board is effectively the brain of the boiler. It is programmed to ensure everything is running as it should.