Diagnosis
No, this is not normal behavior. The combustion fan on the Daniel Boone Prime Plus is designed to operate only during the startup phase (to ignite pellets) and intermittently during the cook cycle to regulate temperature. If the fan is spinning while the unit is powered off or completely cold, you are experiencing a mechanical failure of the relay on the main control board. The relay is an electromagnetic switch that opens and closes to send 120V power to the fan motor. Over time, the internal contacts of the relay can "weld" together due to electrical arcing or heat stress, causing the circuit to remain closed. This means the fan is receiving a constant stream of electricity regardless of what the microprocessor is commanding. You can confirm this by unplugging the grill from the wall; if the fan stops immediately and restarts the moment you plug it back in (without even powering the grill "on"), the relay is definitively stuck in the closed position.
How to Fix It
Because the relay is soldered directly onto the proprietary circuit board, the entire controller assembly must be replaced to restore proper functionality.
- Power Down: Completely disconnect the power cord from the 120V AC outlet. Do not attempt to service the board while the unit is plugged in, as the fan circuit carries live current.
- Remove the Faceplate: Locate the two Phillips-head screws on the underside of the controller housing. Remove these screws and gently pull the control panel forward to expose the internal wiring.
- Document Wiring: Before disconnecting anything, take a clear photo of the wiring harness. There are multiple multi-pin connectors for the RTD (temperature probe), the fan, and the auger motor.
- Disconnect Harnesses: Press the plastic release tabs on each connector and pull them straight out. Be careful not to tug on the wires themselves, as the insulation can become brittle from heat.
- Swap the Board: Remove the mounting screws securing the controller board to the chassis. Lift the failed board out and install the replacement assembly (ensure you have the Prime Plus specific board, as the standard Daniel Boone board has different voltage regulators).
- Reassemble: Plug the harnesses back into their respective slots until you hear a distinct click. Secure the board and screw the faceplate back into position.
- Test: Plug the unit in. The fan should remain silent until you hit the "Power" button and initiate a startup sequence.
If That Didn't Work
- Check for Shorted Wiring: Inspect the wiring loom running from the controller down to the fan motor. If the insulation has melted or been chewed by rodents, the hot wire may be touching the fan's power lead, bypassing the relay entirely. Look for blackened wires or exposed copper near the hopper base.
- Inspect the Fan Motor: While rare, a catastrophic short within the fan motor's internal windings can occasionally cause erratic behavior. If a new board doesn't fix it, replace the combustion fan motor (ensure the RPM rating matches the Prime Plus specifications to avoid overheating the new board).
- Verify Power Source: If you are using a surge protector or a smart plug, bypass it and plug the grill directly into a GFCI wall outlet. In rare cases, electrical noise or "dirty" power can cause the microprocessor to glitch and trigger the relay, though this usually doesn't happen when the unit is powered off.
Heads Up
- Avoid Power Strips: Always plug your Daniel Boone Prime Plus directly into a wall outlet. The initial draw of the auger and fan can trip cheap surge protectors, which sometimes causes voltage spikes that weld the relay closed.
- Clean the Fan Vent: Every 6 months, use compressed air to blow out the fan housing. Dust and pellet fines buildup can cause the fan to work harder, increasing the heat load on the relay and shortening the board's lifespan.
- Temperature Probe Care: When replacing the board, check your RTD probe for kinks. A faulty probe can cause the board to "panic" and run the fan at 100% to prevent a perceived overheat, which can mimic a stuck relay.