Navien Premix Blower Fan Assembly 30017201A

The Navien Premix Blower Fan Assembly is the combustion air fan unit used on Navien NCB-CE ERP condensing boilers. It supplies the premix burner with a controlled flow of air, working alongside the gas valve and PCB to maintain correct combustion across the modulation range. The assembly is supplied as a complete fan unit with part number 30017201A.

• Boiler locks out or fails to ignite, with a fan or air pressure related fault code logged
• Fan noisy in operation — bearing rumble, scraping or intermittent squealing
• Fan does not spin up at the start of an ignition sequence, or runs at a fixed speed regardless of demand
• Repeated flame failure or unstable combustion after the fan and venturi have been checked
• Visible damage, contamination or stiffness when the impeller is turned by hand

• Confirm the boiler model and ERP variant against the fitment list above
• Check the fault code and verify the fan is the failed component rather than the air pressure switch, venturi or wiring
• Inspect the fan mounting, gasket and electrical plug for damage that may also need attention
• Have the boiler isolated and, where required, the gas supply turned off before fitting