LG 2820 Sump Pump Not Working? Try This First [2026]

Quick Fix Summary

Most LG sump pump Model 2820 failures come down to a stuck float switch, an airlocked discharge, or a clogged intake. Unplug the pump, free the float so it moves smoothly, add or clear a 1/8 inch weep hole above the pump to break airlock, and remove debris from the intake and impeller. These quick actions restore flow for the majority of homeowners.

Step-by-Step Troubleshooting

Use the steps below to safely diagnose and fix your LG sump pump Model 2820. Read each step fully before proceeding. If water is rising rapidly, prioritize safety and call a professional.

1. Kill power and assess safety. Unplug the pump from the GFCI outlet and switch off the circuit breaker if needed. Water and electricity are a dangerous mix, so wear rubber-soled shoes and avoid standing water. Test the outlet with a small lamp or receptacle tester to confirm power. If the GFCI keeps tripping, do not bypass it; moisture intrusion or a damaged cord may be present.
2. Verify float switch movement and switching. The LG 2820 typically uses a vertical float switch. Clear any sediment, zip ties, or pit cover obstructions so the float moves freely from bottom to top. Manually lift the float and listen for a click that indicates the switch is actuating. If you have a multimeter, unplug the pump and check float switch continuity; it should read closed when the float is up and open when down. Replace or adjust the float if it binds or fails continuity.
3. Break airlock in the discharge. Air trapped in the vertical discharge can prevent water flow even though the motor runs. Many sump installations require a small 1/8 inch weep hole drilled in the discharge pipe, just above the pump outlet and below the check valve. Inspect and clear this hole; if missing, add one and deburr it. Cycle the pump while observing for a steady stream at the weep hole and rising discharge output.
4. Inspect the check valve and discharge line. Confirm the check valve arrow points away from the pump toward the house drain or outflow. A reversed valve will block flow. Shake the valve lightly to hear the flapper move; a stuck or swollen flapper can restrict water. Open unions, clear debris, and ensure the discharge is not frozen, kinked, or crushed. Use a rubber coupling to reduce vibration and add a cleanout access if the line is prone to silt.
5. Clean the pump intake and impeller. Disconnect the pump, lift it from the pit, and rinse it with clean water. Remove the intake screen or volute cover as the design allows. Clear pebbles, iron bacteria slime, and stringy debris from the impeller blades and volute. Spin the impeller by hand; it should rotate smoothly without binding. Reassemble with intact gaskets or O-rings to prevent leaks back into the pit.
6. Test electrical health and motor protection. With the pump unplugged, inspect the cord for nicks and the strain relief for cracks. If the motor hums but will not start, the start or run capacitor (common on PSC motors) may be weak. Many units include thermal overload protection; if the pump shut down after prolonged running, allow 30 minutes to cool and try again. A qualified technician can measure capacitance and winding resistance and compare to nameplate values; replace components as needed.
7. Check head height against pump capacity. Excess vertical lift reduces flow. Measure from the pump outlet to the point where the pipe discharges horizontally; this is your static head. Compare to the LG 2820 nameplate and performance curve. If you have more than roughly 10 to 15 ft of lift plus long horizontal runs, expect reduced gallons per hour. Undersized pumps will run long cycles and may overheat. Consider upsizing or reducing friction with larger diameter pipe if the head is near the pump's limit.
8. Eliminate noise, vibration, and short cycling. Loud rattling often points to cavitation, rigid piping without isolation, or a chattering check valve. Add a rubber pad under the pump, use a rubber coupler on the discharge, and secure vertical pipe with a bracket. Short rapid cycles indicate a float set too low or an undersized pit; adjust the float tether/stop so the pump runs for several inches of water height and off cycles leave water below the inlet.

Technical specifications (typical for LG sump pump Model 2820)

Always confirm on the pump's nameplate, but many submersible sump pumps in this class share these specs:

• Power: commonly 1/3 to 1/2 HP, PSC motor, 120 VAC, 60 Hz
• Amps: often in the 6 to 9 A running range
• Discharge size: typically 1-1/2 inch NPT vertical outlet
• Max head: around 20 to 30 ft; flow decreases as head increases
• Flow rate: roughly 3,000 to 4,500 GPH at 10 ft of lift
• Switch: integrated vertical float or piggyback float switch
• Housing: thermoplastic or cast iron with stainless fasteners
• Thermal protection: auto reset overload is common
• Recommended pit: minimum 18 inch diameter, 22 inch depth

If your nameplate differs, use your actual values when evaluating capacity and runtime.

Common issues and symptoms

• Pump runs but no water moves: airlock, blocked intake, reversed or stuck check valve, collapsed discharge
• Hums and trips GFCI: seized impeller, weak capacitor, moisture in motor or cord damage
• Short cycling: float too low, pit too small, check valve leakback causing rapid re-trigger
• Continuous running: stuck float, very high inflow, discharge restriction increasing run time
• Excessive noise: cavitation from low water at intake, rigid piping vibration, check valve chatter

Preventive maintenance tips

• Test the pump and float monthly by adding water until the float lifts.
• Flush the pit quarterly; remove sludge that can jam the impeller.
• Verify the weep hole stays open; clear mineral buildup with a small bit.
• Inspect the check valve annually; replace if the flapper sticks or leaks back.
• Keep a backup pump and battery or water-powered backup if flooding risk is high.

Replacement Parts

When components wear or fail, targeted replacements can restore performance without buying a whole new pump. Use the exact model number and nameplate specs when ordering. Many of these parts are readily available online. Shop verified parts at https://www.amazon.com/s?k=LG+sump+pump+Model+2820&tag=manuallogic-20.

• Float switch assembly: Replaces failed or sticky float switches that cause short cycling or no-start conditions. Choose integrated or piggyback style to match your pump.
• Check valve (1-1/2 inch NPT): Prevents water from flowing back into the pit and minimizes rapid re-triggers. Look for a quiet, spring or flapper type rated for sump duty.
• Impeller and volute gasket kit: Restores pumping efficiency after wear or damage from debris. Replace O-rings or gaskets to stop internal bypass leaks.
• Run/start capacitor (PSC motor): Fixes humming or hard-starting motors. Match microfarad rating and voltage to your original component.
• Power cord and strain relief: Eliminates nuisance GFCI trips caused by cracked insulation or compromised seals. Ensure watertight cord grommets.
• Discharge pipe, unions, and rubber couplers: Reduces vibration and simplifies maintenance. Use schedule 40 PVC with a union near the pump for quick removal.
• Pit cover and grommets: Keeps debris out and supports clean float travel, reducing jams and odors.
• Anti-siphon weep hole fitting: A small insert that keeps the 1/8 inch vent open and properly sized to prevent airlock.

After installing any replacement part, retest by filling the pit. Confirm proper float travel, startup, steady flow, and shutoff. Record runtime and water level so you notice changes early. With correct setup, intact venting, and clean intake, the LG sump pump Model 2820 should cycle reliably and keep your basement dry.