Why Does My Robot Mower Keep Stopping?

On this page4 sections

1. Read the reason first
2. The usual causes
3. Fix it in order
4. When it is the mower, not the lawn

What is going wrong

• 1Long or wet grassA deck working through more than it is rated for stalls, backs off and stops, and does it in the thickest parts first.
• 2Signal edgesRepeated stops at the same boundary are a signal problem rather than a traction one.

Read the reason first

Unlike a stuck vacuum, a mower that stops normally tells you why, on its screen or in the app. Start there; the fixes below map to the common messages.

The usual causes

• Wet or very tall grass. Wet clippings clog the deck and bog the blade; grass above the cutting range stalls the motor. Mow when dry, and drop the height for a first pass on long grass.
• Slope near the limit. Most consumer mowers handle roughly 20 to 30 percent grade. Near that limit, wet or loose turf makes the wheels slip and the mower stops.
• Lift or tilt. Safety sensors stop the blade the instant the mower is lifted or tips past a set angle. Uneven ground, molehills, or a wheel dropping into a hole can trip this.
• Blocked wheels or blade disc. Packed grass and mud around a wheel or the blade disc make the mower think it is stuck.
• Lost boundary or satellite signal. Wire mowers stop when the perimeter loop breaks; wire-free RTK mowers stop when they lose the satellite fix under trees or beside buildings.

Fix it in order

1. 1

   Deck cleared

   Clear and clean.

   Power off, clear packed grass from the wheels, deck, and blade disc, and check the blades turn freely.

2. 2

   Dry lawn

   Mow dry, in stages on long grass.

   Reschedule around watering and rain; on overgrown lawns cut from a higher setting down over several passes.

3. 3

   Hollow filled

   Smooth the trouble spots.

   Fill holes and level molehills where the tilt sensor trips, and set a no-go zone around a slope it cannot hold.

4. 4

   Wire break

   Check the boundary or signal.

   For wire mowers, look for a break in the loop (usually shown as a signal error). For RTK mowers, note whether stops cluster under tree canopy or beside the house, where the sky view is poor.