my milwaukee m18 drill just stopped working and feels really hot, is that bad?

Diagnosis

This is a classic case of thermal overload triggering the internal safety circuitry of the 2801-20. Inside the housing, the motor and trigger assembly generate significant heat during high-torque applications—such as driving large lag bolts or drilling through dense hardwoods. When the internal thermistor detects that the motor windings or the electronic control board have exceeded a safe operating threshold, it cuts power to the switch to prevent the copper windings from melting or the plastic housing from warping. You can confirm this is a thermal shutdown if the tool stopped abruptly during a heavy load, the casing feels hot to the touch (particularly near the rear of the motor housing), and the tool refuses to engage even when you pull the trigger fully. If you are using a High Output battery, the battery's own internal Battery Management System (BMS) may also have tripped a thermal lockout, which communicates with the tool to kill power to protect the lithium cells from permanent degradation or venting.

How to Fix It

To reset the thermal protection and return the drill to service, follow these precise steps:

1. Immediately remove the M18 battery pack from the base of the drill. This is critical because the battery continues to provide a small amount of current to the tool's electronics, which can slow the cooling process.
2. Place the drill and the battery on a non-conductive, cool surface (like a wooden workbench). Do not place them on a hot metal surface or in direct sunlight.
3. Allow the tool to sit undisturbed for at least 20 to 30 minutes. The internal components have high thermal mass and take longer to cool than the outer plastic shell.
4. While waiting, check the drill bit or driver bit for dullness. A dull bit increases friction and forces the motor to draw more current (amps), which accelerates heat buildup. Replace any worn bits.
5. Once the tool casing feels cool to the touch, slide the M18 battery back into the rails until it clicks firmly.
6. Test the trigger with a light load to ensure the electronic lockout has reset.

If That Didn't Work

• Check the Battery State: If the drill is cool but still won't start, the battery may be in a "deep sleep" or thermal lockout mode. Place the battery on an M18 charger. If the charger flashes a red light, the battery is too hot or too cold to charge. Leave it on the charger; the charger will automatically begin the charging cycle once the battery reaches the required temperature window (32°F to 104°F).
• Inspect the Carbon Brushes: While the 2801-20 is built for durability, excessive heat can cause carbon brushes to wear unevenly or spark. If the tool smells like ozone or burnt plastic, the brushes may have fused or worn down to the limit. This requires a teardown to inspect the motor armature.
• Clear the Vents: Check the motor vents at the rear of the tool. If they are clogged with sawdust, drywall dust, or grease, the internal fan cannot evacuate heat. Use compressed air to blow out the housing from the rear vents toward the front to clear obstructions.
• Test with a Different Battery: Swap the current battery for a known-working M18 pack. If the tool works immediately with a different battery, the original battery's internal cells are likely damaged or the BMS is failing, requiring a battery replacement.

Heads Up

• Avoid "Trigger Hammering": Rapidly pulsing the trigger under heavy load creates massive current spikes that generate heat faster than the internal fan can remove it. Maintain a steady, firm squeeze.
• Match the Battery to the Job: For high-torque applications, use a higher capacity battery (5.0Ah or higher). Smaller batteries (2.0Ah) have higher internal resistance and will heat up significantly faster under load.
• Temperature Storage: Never store your M18 tools in a vehicle during summer or winter. Extreme temperatures can permanently reduce the capacity of the lithium-ion cells and cause the tool's electronics to malfunction.
• Listen for the Load: If you hear the motor "bogging down" or the RPMs dropping significantly, stop immediately. This is the primary warning sign that you are exceeding the tool's thermal capacity.