How To Drain A Swimming Pool With The Pool Pump
Utilizing your existing filtration equipment to pump out water is a cost-effective alternative to renting a submersible trash pump, provided your filtration system features a multiports valve with a waste setting. This comprehensive guide covers the technical prerequisites, step-by-step execution, and critical safety thresholds required to empty your vessel safely without damaging your pump motor or shifting the pool shell.
Pre-Operation & Equipment Checklist
Draining water using your filtration system requires careful preparation to prevent equipment burnout, environmental contamination, and structural damage to the pool basin. Before initiating any extraction, evaluate the hydrostatic pressure of your local water table, check municipal regulations regarding wastewater disposal, and assemble all necessary monitoring tools.
- Essential Equipment & Materials: A heavy-duty discharge hose or backwash hose long enough to reach a legal runoff point, hose clamps, a garden hose for pressure rinsing, a submersible utility pump as a backup, and a hydrostatic relief valve test kit.
- Prerequisite Knowledge & Standards: Familiarity with your filtration system architecture, understanding of local municipal storm drain versus sanitary sewer codes, and awareness of the specific structural type of your pool (vinyl-liner, fiberglass, or concrete/gunite).
- Budget & Time Benchmarks: Minimal financial investment if you already own a discharge hose, with total execution time ranging from 4 to 12 hours depending on vessel volume and system flow rate.
Step-by-Step Drainage Execution Workflow
Step 1: Inspect the Plumbing and Select a Proper Discharge Zone
Locate the waste line or backwash port on your multiport valve and secure a heavy-duty discharge hose using a metal hose clamp to prevent high-pressure blowouts. Route the hose toward a designated sanitary sewer cleanout, a sloped lawn area capable of absorbing massive runoff without eroding neighbor properties, or a street storm drain only if permitted by local environmental ordinances.
Warning: Never pump chlorinated or chemically treated pool water directly into natural waterways, lakes, or streams, as high chemical concentrations can devastate local aquatic ecosystems and trigger heavy municipal fines.
Step 2: Turn Off the Power Supply at the Breaker
Navigate to your main electrical service panel or the dedicated pool equipment sub-panel and flip the circuit breaker powering the filtration pump into the off position. Working on or adjusting a pressurized multiport valve while live electricity feeds the motor risks severe electrical shock and mechanical damage to internal diverter gaskets.
Step 3: Configure the Multiport Valve to the Waste Position
Push down firmly on the multiport valve handle, rotate it clockwise until the indicator pointer locks securely into the Waste or Drain position, and release the handle. In this configuration, incoming water pulled from the main drains or skimmers bypasses the filter media entirely and shoots straight out of the waste port, preventing debris from clogging your sand, DE, or cartridge elements.
Step 4: Prime and Restart the Pump
Turn the circuit breaker back on to activate the pump motor, keeping a close eye on the pump basket to verify that it primes correctly and pulls water smoothly. If the water level drops below the skimmer throats during the process, immediately plug the skimmer holes using winterizing gizzmo plugs or plastic plates to prevent the pump from drawing dry air and burning out the shaft seal.
Step 5: Monitor Flow Rates and Bottom Sediment
Supervise the operation continuously to ensure the discharge hose remains unkinked and water exits at a steady rate. As the water level approaches the final few inches of the shallow end, use a pool brush to sweep remaining debris and dirty sludge toward the main drain or the suction line to prevent sediment accumulation against the walls.
| Valve Setting | Bypass Filtration? | Primary Operational Purpose | Recommended Use Case |
|---|---|---|---|
| Filter | No | Normal water circulation and debris capture | Daily sanitation and routine filtration cycles |
| Backwash | Yes | Reverses internal water flow to clean filter media | Clearing sand or DE filter beds of trapped particulate |
| Waste | Yes | Directs water straight out of the system | Lowering water levels, removing heavy algae blooms, or draining |
| Recirculate | No | Bypasses filter to circulate water rapidly | Distributing chemicals quickly with a damaged filter |
How To Drain Above Ground Pool With Main Drain at Nathaniel Ackerman blog
Common Site Failures and Field Fixes
- Root Cause: The pump loses its prime and begins making a high-pitched whining noise as water levels drop below the skimmer line.
- Actionable Fix: Immediately turn off the system at the breaker, fill the pump pot manually with a garden hose to re-establish the prime, and use a dedicated pool skimmer plate to block air intake from the skimmer while drawing exclusively from the main drain.
- Root Cause: The vinyl liner begins pulling away from the coping tracks or wrinkles form on the floor as hydrostatic pressure forces the liner upward.
- Actionable Fix: Stop the drainage process immediately; if you are emptying a vinyl liner pool completely, you must leave at least one foot of water in the shallow end to maintain structural wall tension.
- Root Cause: The multiport valve spider gasket slips out of alignment, causing water to leak simultaneously out of the waste line during normal filtration.
- Actionable Fix: Depress and turn the valve handle only in a clockwise direction while the pump is powered completely off, and replace the internal rubber spider gasket if it shows signs of cracking or degradation.
Frequently Asked Questions
Can I drain my pool completely using just the pool pump?
No, standard centrifugal pool pumps cannot lift water once the suction source drops below the level of the pump intake or skimmers. Furthermore, once water levels drop below the foot-well or main drain, the pump will run dry, destroying the impeller shaft seal and motor bearings.
How long does it take to empty a pool using the waste setting?
The duration depends directly on your pump's horsepower, flow rate (measured in gallons per minute), and the total volume of your pool. A standard residential pump rated at 1.5 horsepower typically moves between 40 to 60 gallons per minute, requiring anywhere from 4 to 10 hours for a standard 15,000-gallon pool.
Is it safe to empty a concrete pool entirely during the rainy season?
Completely emptying concrete or gunite pools in areas with high water tables is extremely risky because the surrounding saturated soil can exert massive upward hydrostatic pressure, cracking the shell or causing the entire pool structure to pop out of the ground like a boat hull. Always consult a local pool professional if you need to perform a full structural evacuation.
Where should I direct the discharged water?
The safest and most legally compliant destination is your property's sanitary sewer cleanout, which routes wastewater to a municipal treatment plant. Alternatively, you can discharge dechlorinated water over a wide, well-vegetated lawn area where it can infiltrate slowly without causing surface erosion or flooding neighboring lots.
Ready to tackle your seasonal pool maintenance with total confidence? Partner with our team of water treatment experts to find heavy-duty replacement parts, professional-grade discharge hoses, and customized seasonal drainage plans tailored to your exact vessel specifications.
