Fixing Runtime Decrease in Coway AP-1520

When the Coway AP‑1520 air purifier starts to shut down earlier than expected, it can be frustrating. A drop in runtime is often a sign of an underlying problem that can usually be fixed with a few simple steps. The following guide explains why runtime may decrease, how to diagnose the issue, and the best practices to restore your unit to its full performance.

Understanding the Coway AP‑1520 Runtime

The AP‑1520 is engineered to run continuously for 24 hours on a single cycle in its standard mode. Runtime is controlled by two main factors: the air flow system (fans, filter path) and the electronic control board. If either component begins to draw more power or lose efficiency, the unit will cycle off sooner to protect its internal circuitry.

Key points to keep in mind:

• Filter status: When filters become clogged, airflow drops and the motor works harder, triggering early shutdown.
• Sensor feedback: The device monitors indoor air quality, temperature, and humidity. Inaccurate sensor readings can cause the unit to think it is in a low‑quality environment and stop prematurely.
• Electrical load: Power fluctuations or a faulty internal relay can limit available voltage, reducing runtime.
• Software updates: Firmware issues sometimes manifest as runtime anomalies. A quick reboot or update may resolve them.

Step‑by‑Step Troubleshooting

1. Check the Filter Condition

A clean filter is essential for optimal performance. Over time, HEPA and activated carbon layers accumulate particles, making the airflow harder for the motor to push.

• Inspect the HEPA filter: Remove the top panel and look for a darkened or thickened layer. If the filter appears dirty, it’s time for a replacement.
• Inspect the activated carbon filter: This layer is usually light grey or beige. If it feels damp or smells musty, it is saturated and should be replaced.
• Replace filters: Turn the unit off, unplug it, and follow the manufacturer’s instructions for removal and installation. Most Coway units use a “click‑and‑lock” system that allows for a quick swap.
• Reset the filter indicator: After installing fresh filters, press the filter‑reset button (usually a small recessed button) until the indicator light turns green or a new cycle starts.

After the filters are fresh, monitor the runtime for a few days. A clean filter can restore a 24‑hour cycle.

2. Verify Power Supply Stability

The AP‑1520 requires a stable 120‑volt outlet. Voltage drops can trigger the built‑in protection to cut power.

• Use a dedicated outlet: Avoid multi‑purpose power strips that may have insufficient current rating.
• Check the outlet: Plug a small appliance into the same outlet to verify it’s providing steady voltage. A voltage tester can confirm 120 volts.
• Inspect the power cord: Look for fraying, kinks, or exposed wires. A damaged cord should be replaced immediately to prevent electrical faults.

If the outlet is unstable, consider moving the purifier to a different location or using a surge protector that also offers voltage regulation.

3. Examine the Fan and Motor

A fan that is beginning to wear out can consume more power than usual, leading to a reduced runtime.

• Listen for unusual noises: A rattling or grinding sound may indicate worn bearings or debris in the fan.
• Check fan speed: Most units allow you to manually set the fan speed. Try a lower setting to see if runtime improves. If the fan runs at high speed for an extended period, the motor may be overworking.
• Clean the fan blades: Unplug the unit, remove any dust buildup with a soft brush or vacuum. Dust on the blades can obstruct airflow.

If the fan remains noisy or the motor feels hot after normal operation, it may need professional servicing or replacement.

4. Inspect the Sensors

The Coway AP‑1520 uses built‑in sensors to assess air quality and adjust performance accordingly. Faulty sensor readings can trigger premature shutdowns.

• Air quality sensor: If the sensor is covered in dust, it may misinterpret particle concentration. Gently wipe it with a dry microfiber cloth.
• Humidity sensor: Ensure that humidity levels are within the normal range (30‑50 %). Extremely low or high humidity can influence the control board.
• Temperature sensor: A blocked temperature sensor may cause the unit to misjudge ambient conditions. Clean the sensor housing if needed.

Because these sensors are sealed inside the unit, if cleaning does not resolve the issue, you may need to have the unit serviced by a qualified technician.

5. Perform a Software Reset

Sometimes the electronic control board can encounter a glitch that reduces runtime.

• Power cycle: Turn the unit off, unplug it for at least 30 seconds, then plug it back in and turn it on. This can clear temporary software bugs.
• Factory reset: Many Coway models allow a reset via a button combination. Check the user manual for exact instructions.
• Firmware update: Visit the official Coway website or use the Coway app to check for any firmware updates. Download and install any available updates to fix known bugs.

After a reset or update, observe the runtime again. A fresh software state often restores normal operation.

6. Monitor Indoor Air Quality

If the AP‑1520 consistently cycles off due to high particle or CO₂ levels, the runtime will naturally reduce.

• Keep windows and doors closed: During operation, limit open windows to reduce particulate influx.
• Use a separate HEPA filter: In very dusty environments, consider an extra HEPA filter to reduce load on the purifier.
• Ventilate the area: When cooking or using chemical cleaners, open windows for a brief period to allow fresh air in before turning on the purifier.

By maintaining a cleaner indoor environment, you reduce the burden on the purifier, allowing it to run longer.

7. Check the Air Flow Path

Dust or debris in the air intake or return can restrict airflow, causing the motor to work harder.

• Inspect the intake grill: Clean any visible dust or lint with a vacuum or compressed air.
• Inspect the return vents: Make sure there is no blockage by furniture or rugs that could impede airflow.

Clear vents and grills promote smoother operation and can improve runtime.

8. Ensure Proper Placement

Placement influences airflow and overall efficiency.

• Center of the room: Place the purifier roughly in the middle of the room to maximize air intake and output.
• Clearance: Leave at least 18 inches of space around the unit to avoid air recirculation issues.
• Avoid corners: Corners can trap stagnant air; a more open position is preferable.

Optimal placement reduces the load on the motor, allowing the unit to maintain full runtime.

9. Examine the Electrical Components Internally

If the above steps do not resolve runtime issues, you might need to inspect internal components.

• Open the case: Only do this if you are comfortable with electronics and after disconnecting power. Look for corroded connections or visible wear on the PCB.
• Check the capacitors: Swollen or leaking capacitors can cause early shutdowns. Replacing them requires soldering skills.
• Look for burned markings: Heat‑damaged components often indicate electrical stress.

If you detect any abnormal conditions, it is safest to contact Coway support or a certified repair service.

10. Contact Coway Customer Support

When all troubleshooting steps fail, reaching out to Coway’s customer service is the best course of action.

• Provide a detailed description: Mention runtime, any error lights, and what steps you have already taken.
• Share your serial number: You can find it on the base of the unit or in the user manual.
• Ask about warranty coverage: If your unit is still under warranty, many repairs or replacements are covered.
• Request a service appointment: A technician can perform an in‑depth diagnostic and repair.

Coway’s support team often provides quick solutions, especially for firmware updates or known hardware faults.

Preventive Maintenance Tips

Keeping the AP‑1520 in top shape reduces runtime problems and extends its life.

• Replace filters every 6–12 months: The exact interval depends on usage and environment. Coway provides a filter‑change calendar to help you schedule replacements.
• Clean the unit monthly: Wipe the exterior and intake with a damp cloth. Never submerge the unit in water.
• Run the unit on a schedule: Set a consistent operating cycle that aligns with your household’s schedule. This helps the unit stay in a steady state.
• Keep firmware up to date: Regularly check for updates to keep the control board running smoothly.
• Avoid extreme temperatures: Operate the unit within 60–80 °F. Extreme heat or cold can affect electronics.

Adhering to these practices will help maintain a 24‑hour runtime and reduce the likelihood of future issues.

Summary

Runtime decrease in the Coway AP‑1520 can stem from a variety of causes—clogged filters, electrical instability, faulty sensors, or simple software glitches. By systematically checking each of these areas, you can usually restore full runtime without professional help. If the problem persists, contacting Coway support ensures you receive the right service. With regular maintenance and mindful placement, the AP‑1520 will continue to provide clean air for years to come.