United States Stove 86620 Agitator Drive Shaft for Pellet and Multi-Fuel Stoves -- NBK Parts 20263

Stop Clinkers, Restore Reliable Combustion

The agitator drive shaft is the mechanical link between your stove's feed motor and the agitator bar that stirs fuel inside the burn pot. Without it working correctly, pellets or multi-fuel media can bridge, pack, or clinker -- starving the fire and triggering fault shutdowns. Replacing a worn or broken shaft is one of the simplest repairs you can make to get your stove back to full output.

Part number 86620 (also catalogued under NBK Parts as 20263) is built to the same spec as the original factory component. At just 0.05 lbs it ships light, but order it before heating season so you have it on hand when you need it.

What the Agitator Drive Shaft Does

Pellet and multi-fuel stoves feed solid fuel into a burn pot where it is ignited and combusted. Over time, ash, clinkers, and compacted fuel can build up and prevent new fuel from burning cleanly. The agitator -- a small rotating bar or paddle inside the burn pot -- is driven by a dedicated motor to continuously stir the fuel bed. The drive shaft is the coupling between that motor and the agitator bar.

A cracked, bent, or stripped drive shaft will cause the motor to spin freely while the agitator bar stays still. Symptoms include:

• Stove shuts down shortly after ignition (fuel not burning evenly)
• Visible clinker buildup in the burn pot during inspection
• Motor running but no audible movement from the agitator
• Error or fault codes related to combustion or low heat output

Compatible Stove Models

Verify your model number on the data plate (typically located on the back or underside of the stove) before ordering.

• US Stove models: 6039, 6039HF, 6039T, 6100, 6220, 6500, 8500
• King models: Multi-Fuel 8500

Installation Overview

This is a mechanical replacement part. General steps for most affected models:

• Allow the stove to cool completely before beginning any service work
• Disconnect power to the unit
• Access the burn pot area and agitator motor assembly per your model's service layout
• Remove the retaining fastener or clip securing the old drive shaft to the motor output and agitator bar
• Install the new 86620 shaft, confirm it seats fully on both ends
• Restore power and run a short test cycle to confirm agitator movement before relying on the stove for heat

Part Identification

Physical Specifications

Compatible Models -- US Stove

Compatible Models -- King

Function Reference