the powerhead on my marin won't spin the brushroll, the green light is on but the roller is just dead

Diagnosis

The Miele Complete C3 Marin utilizes the SEB 228 electrobrush powerhead. When the green indicator light is illuminated but the brushroll remains stationary, it confirms that the electrical circuit from the canister to the head is intact, but the mechanical transfer of energy to the bristles has failed. This is almost always caused by one of two things: a snapped drive belt or a tripped thermal overload protector. Because the SEB 228 is designed for high-pile carpets, it is prone to "brushroll jam." If the roller encounters a stubborn object—like a stray sock or a clump of thick yarn—the motor continues to push against the resistance. This creates friction that either snaps the rubber drive belt or causes the motor to overheat rapidly. The green light stays on because it is powered by the 120V line, but the internal thermal fuse will cut power to the motor itself to prevent a total burnout, leaving the head "electrically live" but mechanically dead.

How to Fix It

To resolve this, you must perform a mechanical inspection of the drive system. Ensure the vacuum is unplugged from the wall outlet before proceeding.

1. Flip the SEB 228 powerhead over to expose the underside. Locate the brushroll and check for any visible obstructions, such as long hairs wrapped tightly around the ends of the roller.
2. Use a pair of scissors to carefully cut away any hair or string wrapped around the brushroll. If the hair is wound tightly around the bearings, the roller cannot spin even if the belt is intact.
3. Remove the brushroll from the housing. Depending on your specific production run, you may need to remove the end caps or unscrew the retaining clips. Slide the roller assembly out of the chassis.
4. Inspect the rubber drive belt. If the belt is snapped, stretched (showing a gap between the pulley and the belt), or has slipped off the motor spindle, it must be replaced.
5. If replacing the belt, loop the new belt around the small motor drive pulley first, then stretch it over the larger brushroll pulley. Ensure it is seated deeply in the grooves to prevent future slippage.
6. Reinstall the brushroll, ensuring it clicks firmly into the side bearings.
7. Plug the unit back in and test on a medium-pile carpet. If the motor was thermally tripped, it may take 30 to 60 minutes of being unplugged to reset the internal fuse.

If That Didn't Work

• Test the Connection Pins: Inspect the gold-plated contact pins where the powerhead connects to the wand. If these pins are bent or coated in dust/debris, the motor may receive enough voltage to light the LED but not enough amperage to actually spin the motor. Clean them with a dry microfiber cloth.
• Check the Motor Carbon Brushes: If the belt is intact and the unit has cooled down but still won't spin, the carbon brushes inside the SEB 228 motor may be worn down to the nubs. This requires a full teardown of the motor housing to replace the brushes, though in most cases, replacing the entire motor assembly is more cost-effective.
• Verify the Height Adjustment: Ensure the height adjustment dial is not set to the "Hard Floor" or lowest setting while on deep carpet. If the head is pressed too hard into a thick rug, the friction can trigger the thermal cutoff immediately upon startup.
• Inspect the Canister Power Settings: Ensure the main canister dial is set to the "Carpet" (brush icon) setting. While the green light suggests power is flowing, some C3 models have intermittent contact in the selector switch that can cause erratic power delivery to the head.

Heads Up

• Avoid "Over-Brushing": Do not leave the powerhead running in one spot for more than 10 seconds. This creates localized heat that can melt the drive belt or trip the thermal protector.
• Hair Maintenance: Check the ends of the brushroll every 30 days. Hair buildup around the bearings creates drag, which puts immense strain on the belt and shortens the motor's lifespan.
• Surface Matching: Never use the SEB 228 powerhead on delicate area rugs or high-pile shag without checking the height adjustment; the aggressive agitation can damage the rug and overheat the motor simultaneously.