Submersible Pump Preventive Maintenance Checklist

⚠️ Disclaimer: These tasks are guidelines only. They do not include lockout/tagout (LOTO), energy isolation, or other safety requirements. Review and verify suitability for your specific equipment and application. Add all required safety procedures per your company's policies and regulatory requirements before use. You are responsible for the safe and appropriate execution of all maintenance activities.

Submersible pumps fail from the outside in. The cable goes first, then the seals, then the motor — and most of it happens underwater where nobody is looking. By the time there's a symptom you can hear or see, the damage is already done.

This checklist covers preventive maintenance tasks for submersible pumps used in wet wells, sumps, and similar applications. It is written for both field technicians executing the PM and maintenance managers building or auditing the program.

For a broader look at pump PM strategy, start with the pump PM fundamentals your program needs.

How to Use This Checklist

Record findings with specificity — not checkboxes. "Cable insulation intact" tells you nothing a year from now. "Cable shows minor abrasion at conduit entry, no insulation breach, flagged for monitoring" tells you everything. The difference between a finding and a checkbox answer is whether someone could read it six months later and know what you actually saw.

Trend your measurements over time. A single megohmmeter reading means almost nothing. The same reading compared against three prior measurements means a great deal. If insulation resistance is dropping — even if it is still above 1 MΩ — that trajectory is the finding.

The field checklist covers the highest-consequence tasks for technicians executing the PM. The reference checklist is the full task library for managers building, auditing, or expanding the program.

Field Checklist — Critical Tasks

Visual Inspection Tasks

Mechanical Inspection Tasks

Operational Checks

Electrical Inspection Tasks

Reference Checklist — Full Task Library

Visual Inspection Tasks

Mechanical Inspection Tasks

Operational Checks

Electrical Inspection Tasks

Failure Modes This Checklist Targets

Cable insulation failure. The power cable runs through wet, abrasive environments. Cuts, kinking, and degraded insulation create ground faults that take out the motor without warning. The cable inspection and megohmmeter tasks catch this while there is still time to act.

Motor winding failure from moisture ingress. When cable entry seals fail or the pump motor casing is compromised, moisture reaches the windings. Insulation resistance trending is the only way to catch this failure mode before it becomes a rewind or a replacement.

Impeller wear and clogging. Rags, solids, and debris erode impellers and reduce flow. A pump that is moving less fluid than it should may still be running — it is just failing slowly. Performance verification and strainer inspection are the check.

Float and sensor fouling. In dirty sump environments, float switches get tangled, coated, and stuck. A pump that can't respond to its level sensor will either run dry or let the wet well overflow. Float inspection every PM is non-negotiable.

Check valve failure and backflow. A check valve that doesn't seat properly lets the discharge column reverse on shutoff. That means water hammer, impeller stress, and a pump that has to fight its own backflow every time it starts. Quarterly valve inspection catches this before it shortens bearing and seal life.

High-level alarm failure. The alarm exists for one reason — to tell someone the pump isn't keeping up before the sump overflows. If the alarm float is fouled or the setpoint has drifted, you don't have a backup. You have a false sense of security.

Related Checklists

• Centrifugal pump PM tasks for above-grade installations
• Sump and sewage pump PM tasks built for similar wet-well applications