Viessmann 7870539 Radial Fan iNR77 with Gas Valve Genuine Viessmann radial fan assembly with integrated gas valve, suitable for selected Viessmann residential boilers. Condition: Used – fully working, tested, and supplied in the original Viessmann box and packaging. This unit was replaced by Viessmann during a warranty fault-finding investigation. The issue was later confirmed to be due to a miscalibrated measuring instrument, not a fault with this component. The fan and gas valve are in excellent working order and were not defective. Ideal replacement part for heating engineers or boiler repairs where a genuine Viessmann component is required.
