The Worcester Bosch tail piece for the CBi Series, Si/C1 Series, CDi Series, SBi Series, High flow, i Junior Series, and RD Series boiler air pressure switches. A vital safety device, an air pressure switch, ensures the boiler fan is working correctly and prevents a build up of toxic gases with no means of venting them in case of a fan failure. The unit's printed circuit board (PCB) closely monitors the air pressure switch to ensure it is fully functional before firing the system up, keeping the

Brand Name	Worcester Bosch