The printed circuit board or ( pcb ) is the boilers central control. It oversees every process that occurs via the sensors, thermostats and switches. 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 essentially the brains of the appliance, ensuring everything is running correctly and safely The printed circuit board or ( pcb ) is the boilers central control. It oversees every process that occurs via the sensors, thermostats and switches. 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 essentially the brains of the appliance, ensuring everything is running correctly and safely This part is present in 3 different boilers in the Glowworm range Please see description for list All new parts come with a 12 month warranty Always ensure a qualified engineer maintains your gas appliances, Manufacturer: Glow Worm