If your home in Ajax, Whitby, Pickering or Oshawa has a finished basement, your sump pump is one of the hardest-working parts of your plumbing system. Most of the year it sits quietly in its pit. Then a spring thaw, a heavy rainstorm or a sudden melt arrives, and it may have to run every few minutes for hours on end.
When a sump pump fails at the wrong moment, the result is a flooded basement, ruined flooring and drywall, and an insurance claim nobody wants. The good news: most failures give warning signs, and a few minutes of maintenance each season prevents the majority of them.
Here is the checklist our licensed plumbers at New Well Plumbing & Heating use, written for Durham Region homeowners.
Why Sump Pumps Matter So Much in Durham Region
Many neighbourhoods across Durham Region sit on clay-heavy soil that drains slowly, and a lot of homes have basements below the water table for part of the year. Add Lake Ontario weather, fast snowmelt in March and April, and intense summer downpours, and groundwater can build up around your foundation quickly.
Your sump pump collects that water from the weeping tile around your foundation and pumps it away from the house before it can seep through the floor or walls. If the pump stops, the water has nowhere to go but in.
Your Seasonal Sump Pump Maintenance Checklist
Do these checks at least twice a year: once in late fall before the freeze, and again in early spring before the thaw.
1. Test the pump with a bucket of water
Slowly pour a bucket of water into the sump pit. The float should rise, the pump should switch on within a few seconds, empty the pit and then shut off on its own. If it hums but doesn't pump, runs without stopping, or doesn't start at all, it needs attention.
2. Check the power supply
Make sure the pump is plugged directly into a working GFCI outlet, not an extension cord, and that the breaker hasn't tripped. A pump that has quietly lost power is one of the most common causes of basement flooding we see.
3. Clean the pit and the inlet screen
Turn off the power, then remove gravel, silt and debris from the pit. Clean the intake screen so water flows freely. Debris is the number one reason floats jam and motors burn out.
4. Make sure the float moves freely
The float switch tells the pump when to turn on. If it's tangled in the power cord or rubbing against the side of the pit, the pump may never start. Adjust the pump so the float has plenty of room.
5. Inspect the discharge line outside
Follow the discharge pipe to where it exits the house. It should be clear, pointing away from the foundation, and draining at least a couple of metres from the house. In winter, check that the outlet isn't frozen or buried under snow, because a blocked line can push water straight back into the pit.
6. Listen to the check valve
The check valve stops pumped water from flowing back into the pit. A loud thud when the pump shuts off is normal; water rushing back down the pipe is not. A failing check valve makes the pump work twice as hard.
7. Test your backup
Storms that knock out power are often the same storms that flood basements. If you have a battery backup pump, test it by unplugging the main pump and pouring in water. Batteries usually need replacing every three to five years.
Warning Signs Your Sump Pump Needs Repair or Replacement
- The pump is more than 7–10 years old and has never been serviced
- It runs constantly, even when it hasn't rained
- It cycles on and off every few seconds
- You hear grinding, rattling or loud vibration
- Visible rust, corrosion or a burning smell from the motor
- Damp spots, musty smells or water stains near the pit or floor drains
If you notice any of these, don't wait for the next big storm. Our team handles sump pump repair and installation across the region and can tell you whether a repair or a replacement makes more sense.
Extra Protection Worth Considering
A sump pump deals with groundwater. It doesn't stop sewage from backing up through your floor drain when municipal sewers are overwhelmed. For full basement protection, many homeowners combine a reliable sump pump with:
- A battery backup or water-powered backup pump, so you're covered during power outages
- A high-water alarm that alerts you before the pit overflows
- A backwater valve on the main sewer line to help stop sewer backups. Installation usually needs a permit, so ask a licensed plumber
- Regular drain inspections, because cracked or root-damaged lines are a common cause of backups (see our drain repair service)
For independent, practical advice on lowering your home's flood risk, the Intact Centre on Climate Adaptation publishes free home flood-protection guides for Canadian homeowners. Your municipality and the Region of Durham are the places to check for local sewer, water and permit information.
What to Do If Your Basement Is Already Flooding
- Stay safe: don't walk through standing water if outlets or appliances may be under water. Shut off power at the panel only if you can reach it safely.
- Check whether the pump has power and whether the float is stuck.
- Move valuables and electronics off the floor.
- Take photos for your insurance company.
- Call a licensed plumber. A slow leak you can't trace may also need a water leak investigation.
Our 24/7 emergency plumbing team responds day and night across Ajax, Whitby, Pickering, Oshawa and the east GTA. If you want to know what happens once we arrive, read what happens during a drain backup emergency job.
Sump Pump FAQs
How often should a sump pump be serviced?
Test it yourself every season and have a plumber inspect it about once a year, ideally in the fall before freeze-up or early spring before the thaw.
How long does a sump pump last?
Most residential sump pumps last around 7 to 10 years. Pumps that run often, or that sit in a pit full of debris, tend to wear out sooner.
Can I install a sump pump myself?
Swapping a like-for-like pump is possible for handy homeowners, but new pits, discharge lines and backwater valves involve drainage work and often a permit. A licensed plumber makes sure it's sized, wired and discharged correctly.
Is a sump pump the same as a backwater valve?
No. A sump pump removes groundwater from around your foundation; a backwater valve stops sewage from flowing back into your home from the municipal sewer. Many homes benefit from both.
Book a Sump Pump Check With a Local Plumber
Whether you need a quick inspection, a new pump or a battery backup, New Well Plumbing & Heating is here to help. We serve homeowners as plumbers in Ajax, plumbers in Whitby, plumbers in Pickering and plumbers in Oshawa, with licensed, insured technicians and upfront pricing.
Contact us today to book your sump pump inspection before the next storm, and read our guide to what causes plumbing emergencies and how to prevent them.
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