Boat bilge pump not working

Symptoms

• Bilge pump doesn't run when water is present or when tested manually
• Pump runs continuously even with no water
• Pump runs but doesn't move water effectively

Likely causes

• CommonBlown fuse or tripped breaker on the bilge circuitA dedicated fuse can blow, especially if the pump has been struggling or partially clogged.
• CommonFloat switch stuck or fouled with debrisDebris in the bilge can jam the float switch in the down (off) or up (on) position.
• PossibleWorn-out or failed pump motorPumps have a service life and can simply wear out, especially if run dry frequently.
• PossibleClogged intake screen reducing or stopping flowDebris blocking the pump's intake can prevent it from moving water even if the motor runs.

What to do

1. Check the fuse or breaker dedicated to the bilge pump circuit and replace/reset if needed.
2. Test the pump manually using the boat's manual bilge switch (if equipped) to see if it runs at all when bypassing the automatic float switch.
3. If the manual switch runs the pump but it doesn't come on automatically with water present, inspect and clean the float switch of any debris or fouling.
4. If the pump doesn't run even with the manual switch, check wiring connections and battery power reaching the pump.
5. Clean the pump's intake screen of any debris that could be blocking water flow even with a working motor.
6. If wiring and switches all check out but the pump still won't run or move water effectively, replace the pump, since this is a critical safety item not worth leaving unreliable.

Tools and parts

• Multimeter
• Basic hand tools

When to call a pro

If you're not comfortable with the boat's electrical wiring, have a marine electrician or mechanic diagnose and repair the bilge system.

Safety