Sump pump replacement in Chantilly.
Sump pump replacement in Chantilly is $697, set in the pit you have now. A new or deeper pit, a battery backup, outside piping or a new circuit costs extra.
- Cast iron pump, quiet check valve
- Extras priced in writing first
- Dedicated plumbing team
Book your sump pump replacement
Slow red ground over shallow rock, and two rules on where the water goes.
The Census doesn’t count basements, so nobody can honestly say how many Chantilly houses have one. Fairfax County’s soil guide does explain what a basement here is up against: the county’s west end, along the Loudoun line, sits on the red sandstone, siltstone and shale of the Triassic Basin, where the soil over the rock is often shallow, 2 to 10 feet to bedrock, and large flat areas drain slowly and poorly.
The county even maps a soil named Chantilly: dark red ground mixed, graded and compacted as the subdivisions went in, and slow to let water through. On one natural soil of the basin’s level uplands, the guide puts a seasonal water table perched on the bedrock 18 to 30 inches down, and says foundation drains and waterproofing are often needed to keep basements dry. Those drains usually empty into the pit.
In 20151 the typical owner’s house went up in 1987, and about 1 in 4 homes is a townhouse. The county’s soil and water district says Virginia groundwater tends to run highest in February and March, after snowmelt and rain. That’s when a worn pump meets its hardest weeks, so a dry day in January is the time to find out it’s tired.
Both sides of Chantilly send the water the same way: out, never into the sewer. Fairfax County calls an unpermitted sump pump tied into the sanitary sewer illegal, since that water can overload the system and push raw sewage into streets, streams and basements. In South Riding, where the typical owner’s house dates from 2006 and nearly half the homes are townhouses, Loudoun Water says sump pumps shouldn’t connect to its sewer lines and wants the water out on the yard, far enough from the foundation that it can’t soak back into the drains. With a narrow townhouse yard and a neighbor close by, that takes planning.
Sump pumps across Chantilly, place by place.
Census figures for the owner-occupied homes in each place, and what to check on a sump pump in houses that age.
| Place | Median home built | Most homes are | Heated with | What to check |
|---|---|---|---|---|
| South Riding | 2006 | single-family houses, about 5 in 10 | gas, about 8 in 10 | Newer basements: the pump may still be the builder’s. |
| Chantilly | 1987 | single-family houses, about 6 in 10 | gas, about 5 in 10 | 1980s and 90s basements: an original pump is long overdue. |
Chantilly houses, by the numbers
From the Census Bureau’s 2020 to 2024 survey, owner-occupied homes unless it says otherwise.
20151, the Fairfax County side
- Median home built1987 Census
- Built before 1980about 2 in 10 Census
- Built since 2000about 2 in 10 Census
- Most homes aresingle-family houses, about 6 in 10 Census
- Heated withgas, about 5 in 10 Census
- Rentedabout 2 in 10 Census
- A basement from the 1980s or 90s is several pumps in by now, or overdue for its next one.
20152, the South Riding side
- Median home built2006 Census
- Built before 1980hardly any Census
- Built since 2000about 8 in 10 Census
- Most homes aresingle-family houses, about 5 in 10 Census
- Heated withgas, about 8 in 10 Census
- Rentedabout 2 in 10 Census
- In a house built since 2000, the pump in the pit may still be the original, and an original is due.
What sump pump replacement costs in Chantilly.
The same price as our sump pump replacement page: one flat number for a new pump in a pit that’s still sound, with what costs extra named right beside it.
- Sump pump replacement, installed in your existing pit$697
- Sump pump and battery backup, installed together$3,200
- A new or deeper pit, discharge line work outside, or a dedicated circuitPriced in writing before we start
$697 covers a new cast iron pump, a quiet check valve, new PVC up to your existing discharge line, a battery water alarm by the pit, the old pump hauled away and a bucket test before we leave.
A battery backup keeps pumping through a power outage, and the outage usually comes with the storm. With a new pump, the pair is $3,200 installed. The sump pump estimator helps you decide whether you need one.
When a sump pump in Chantilly needs replacing.
It can’t keep up in a wet March
In ground this slow, foundation drains can keep feeding the pit for days after heavy rain, right when groundwater runs highest. A pump that used to keep the water well below the rim and now lets it climb while running flat out has usually lost strength. That’s a new pump, not a repair.
You’re in Fairfax County and want a backup
The county’s Flood Mitigation Assistance Program pays back half of a battery backup, up to its cap, after the work is done and paid for. Not the pump itself, and not homes in the Town of Vienna, the Town of Herndon or the City of Fairfax.
It’s past seven years old
Zoeller, who make a lot of the pumps around here, puts a sump pump’s life at seven to ten years. Past seven, replace it on your schedule instead of the storm’s.
After a storm in Chantilly, check the sump pump.
Six checks you can make yourself once the rain lets up, none of them with your hands in the pit. Then call us and we’ll check it all.
Does the pump kick on?
Watch the pit during the rain or right after. The pump should start as the water rises, empty the pit and shut off. A full pit, or a pump that hums and moves nothing, isn’t keeping up.
Is there water where it shouldn’t be?
Walk the basement: the corners, the walls, the floor by the pit, under the water heater and the furnace. Photograph any wet spot before you mop, so we can see where it came in.
Is the discharge line clear?
Outside, find where the pump’s pipe ends. It should be open, not crushed, buried or full of leaves, and aimed away from the house so the water doesn’t run back to the foundation.
Does the check valve hold?
Listen when the pump shuts off. Water rushing back into the pit means the check valve isn’t closing, and the pump has to move that water again.
Did the power go out?
The pump stops when the power does, often at the height of the storm. If the basement took water during an outage, that’s the job a battery backup does.
Water near an outlet? Stay out.
If water is standing near the pit, an outlet or anything plugged in, don’t wade in to check. Call us, and only switch the power off at the panel from somewhere dry.
Not sure what you saw? Call us after a storm and we’ll check it all: the pump, the float, the check valve, the discharge line and where the water came in. If the pump can’t keep up, a new one is $697 installed in your existing pit; a new or deeper pit, a battery backup, discharge line work outside and a dedicated circuit are extra, priced in writing before we start.
How to pick the best plumber for a sump pump in Chantilly.
Questions to ask anybody who quotes you, us included.
Is the price for the whole job?
Ask what the number covers: the pump, the check valve, the pipe, hauling the old one off, a test before they leave. Then ask what costs extra, and get it in writing.
What’s the new pump made of?
Cast iron, ideally. Plastic pumps cost less and are usually the ones that quit early. Ask before the old one comes out.
Do they look at where the water goes?
A discharge line that’s cracked, buried or frozen shut every January leaves the new pump pushing against a closed pipe. Whoever replaces it should check the outside end too.
What our customers say.
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Sump pump questions from Chantilly.
Is there a battery backup rebate in South Riding?
Not from the county. Loudoun County’s flood grant covers a single subdivision, and South Riding isn’t it, so on the 20152 side a backup is yours to pay for in full. The county program shown on this page is for the 20151 side. Installed with a new pump, the pair is $3,200.
Why does my Chantilly pump run when it hasn’t rained?
Usually it isn’t today’s rain. In slow, compacted ground over shallow rock, water that soaked in days ago keeps reaching the foundation drains, and in late winter the groundwater itself is up. Steady running in February is normal. Short bursts every few minutes in a dry August usually point at the check valve or the float switch.
Is it only spring, or do summer storms flood Chantilly too?
Summer too. The Weather Service’s storm records for 20151 include Walney Road closed by flash flooding on Flatlick Branch in October 2011, a water rescue on Old Lee Road at Stonecroft Boulevard in April 2014, and in 2025 water flowing across Lees Corner Road near Route 50 on June 15 and six to eight inches deep across Route 28 south of Westfields Boulevard on July 12. On this slow red ground, a cloudburst like those can keep the foundation drains running for a day or more, so once it passes, watch the pump empty the pit. If it can’t keep up, call us and we’ll check the pump, the float, the check valve and where the line comes out.
How much does sump pump replacement cost in Chantilly?
$697 installed in your existing pit: a new cast iron pump, a quiet check valve, new PVC to your discharge line, a battery water alarm, the old pump hauled away and a bucket test. A new or deeper pit, discharge line work outside, a battery backup and a dedicated circuit are extra, priced in writing before we start. A new pump and a battery backup installed together are $3,200.
Can I check my sump pump myself?
Yes. Pour five gallons of water into the pit. The float should rise, the pump should start within a few seconds, and it should shut off clean once the water’s down. If you hear water rushing back into the pit after it stops, that’s the check valve.
More from SwiftPro in Chantilly.
More from SwiftPro in Chantilly
A new pump before the next storm.
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SwiftPro Heating, Cooling & Plumbing is a licensed, BBB Accredited (A rating), independently owned heating, cooling and plumbing company in Chantilly, serving Chantilly and the rest of Northern Virginia. Virginia contractor license #2705192276. 5.0 stars across 884 Google reviews. SwiftPro maintains a dedicated HVAC team and a dedicated plumbing team.
SwiftPro Heating, Cooling & Plumbing, 4230 Lafayette Center Dr, Suite N, Chantilly, VA 20151, (703) 997-9757. Book online, read our reviews, or see every town we serve.