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Sump & Seal

Guides: sizing, installing and diagnosing, with the part named

Every troubleshooting page here ends where the lead-generation sites stop — at the component that failed and what replaces it.

This is the part of the site people arrive at in a hurry. Something is making a noise, or has stopped making a noise, or there is water where water has never been. The guides below are organized by what you are seeing rather than by what the manual calls it, because at 11pm on a Tuesday nobody is searching for "intermittent switch actuation failure".

A note on how these are written. While researching this site we read a great many troubleshooting pages that describe a symptom in detail, correctly identify the cause, and then end with a call-to-action for a service quote. That is a business model, not an oversight. These pages do the opposite: the component is named, the failure mode is explained, and the replacement part is linked — because you can hold most of them in one hand.

Hand tools laid out beside a sump pump installation

In this section

Start with what you are actually seeing

What is happeningMost likely causeStart here
Runs constantly, or restarts seconds after stoppingFailed check valve, or a float stuck downSump pump keeps running
Will not start at allSwitch, power, or a seized impellerSump pump not working
Runs but no water leaves the pitClogged intake, airlock, or blocked dischargeSump pump clogged
Loud bang when it stopsCheck valve slam — the normal kind, or the failing kindWhy is my sump pump so loud
Trips the breaker or GFCIMoisture in the circuit, or a failing motorSump pump tripping breaker
Nothing wrong yetYou are ahead. Do the annual serviceMaintenance checklist
Symptom to likely cause

If this is an emergency right now

  1. Do not step into standing water in a basement that has live electrical outlets or equipment in it. Kill the circuit from the panel first, or stay out.
  2. If you can safely reach it, confirm the pump is plugged in and that the outlet has power — a tripped GFCI is a genuinely common cause of a dead pump.
  3. If the pit is overflowing and the pump is dead, a wet/dry vacuum buys time. So does a garden hose siphon if the ground falls away from the house.
  4. Once the immediate water is handled, work through basement flooded: what to do in order.
Basic hand tools on a workbench
Most of the repairs in this section need a screwdriver, a bucket and a hacksaw.

The three jobs worth doing before you need them

Test the pump quarterly. Pour five gallons into the pit, watch the float rise, confirm the pump starts, and confirm that it stops. The stopping half is the part people forget to check and the part that floods basements.

Walk the discharge line once a year. Outside, check that the outlet is clear, not buried by a flowerbed, and discharging at least ten feet from the foundation. In winter, check it is not iced over — see sump pump freezing in winter.

Know how old the pump is. Most residential sump pumps last seven to ten years. If yours is past that, it is not a question of whether it will fail but of whether it fails on a dry Tuesday or during the storm that would have needed it. Replacing a working eleven-year-old pump is a rational thing to do.

Questions people ask

How often should a sump pump run?

There is no universal normal. A few cycles a day in wet weather and almost nothing in dry weather is typical. What matters is the change: a pump that suddenly cycles every few minutes in dry weather is telling you something, usually that the check valve has failed or the float is stuck.

Can I replace a sump pump myself?

For a straightforward like-for-like swap in an accessible pit, it is a realistic job for a competent DIYer with a hacksaw and a couple of hours. If it involves new electrical work, a new pit, or any doubt about the circuit, that is the point to bring in an electrician or plumber.

How long do sump pumps last?

Seven to ten years is the usual range for a residential pump, with cast-iron pumps in well-sized pits reaching the top of that range and beyond, and cheap thermoplastic pumps in hard-working pits falling short of it.

Why is my sump pump beeping?

A beep almost always comes from a backup system or an alarm rather than the pump itself: low battery, a failed charger, a backup pump that has had to run, or a high-water float that has tripped. Identify which device is beeping before you silence anything.