How to Maintain Your Dehumidifier for Longevity
A well-maintained dehumidifier can serve your home for a decade or more. Neglected units, however, often fail within just a few years and consume far more energy than necessary. This guide covers everything you need to know about keeping your dehumidifier in peak condition.
Why Maintenance Matters
Dehumidifiers work continuously in challenging conditions, processing litres of moisture-laden air every hour. Dust, dirt, and biological growth can quickly compromise their efficiency. A dirty filter forces the fan motor to work harder, increasing energy consumption by up to 30%. Blocked coils reduce moisture extraction, meaning the unit runs longer to achieve the same result. Stagnant water in the collection tank becomes a breeding ground for bacteria and mould, potentially spreading these contaminants through your home.
Regular maintenance not only extends your unit's lifespan but also ensures it operates at peak efficiency, saving you money on electricity bills while effectively controlling your home's humidity levels.
The Golden Rule
Clean your dehumidifier's air filter every two weeks during active use. This single habit will prevent most performance issues and is the most important maintenance task you can perform.
Weekly Maintenance Tasks
Empty and Clean the Water Tank
Even if your dehumidifier hasn't filled its tank, you should empty and rinse it at least weekly during regular use. Stagnant water develops bacteria within 24-48 hours, and the warm, moist environment inside the tank is ideal for microbial growth. Use warm water and a mild dish soap to wash the tank, rinse thoroughly, and allow it to dry before replacing it.
Pay particular attention to the corners and any small crevices where residue can accumulate. If you notice any pink or dark discolouration, this indicates bacterial or mould growth that requires more thorough cleaning with a diluted white vinegar solution.
Check the Water Level Sensor
Most dehumidifiers have a float mechanism or sensor that triggers automatic shutoff when the tank is full. Debris or mineral deposits can interfere with this sensor, causing the unit to either shut off prematurely or overflow. When cleaning the tank, gently wipe around the sensor area with a soft cloth.
Fortnightly Maintenance Tasks
Clean or Replace the Air Filter
The air filter is your dehumidifier's first line of defence against dust, pet hair, and airborne particles. A clogged filter restricts airflow, reducing efficiency and straining the motor. Most residential dehumidifiers use washable mesh or foam filters that should be cleaned every two weeks during heavy use.
Filter Cleaning Steps
- Remove the filter according to your unit's manual
- Vacuum loose dust using a brush attachment
- Wash in lukewarm water with mild soap
- Rinse thoroughly until water runs clear
- Allow to dry completely before reinstalling (at least 24 hours)
- Never run your dehumidifier without the filter in place
Some premium models use HEPA or activated carbon filters that cannot be washed. These require periodic replacement according to the manufacturer's schedule, typically every 6-12 months depending on usage and air quality.
Monthly Maintenance Tasks
Inspect and Clean the Exterior
Dust and debris accumulate on the external grilles and vents, restricting airflow even before air reaches the filter. Use a vacuum with a brush attachment to clean the intake and exhaust grilles. Wipe down the exterior casing with a damp cloth to remove accumulated dust. Never use harsh chemicals or abrasive cleaners, as these can damage the plastic housing.
Check the Continuous Drain Hose
If you use the continuous drainage feature, inspect the hose monthly for kinks, blockages, or algae growth inside. Disconnect the hose and flush it with a solution of water and white vinegar to prevent biological buildup. Ensure the hose maintains a continuous downward slope to the drain point, as any upward loops can cause water to back up into the unit.
Seasonal Maintenance Tasks
Deep Clean the Coils (Every 3-6 Months)
The evaporator and condenser coils are where the magic happens, and they need periodic attention. First, unplug the unit and allow it to sit for at least an hour. Using a soft brush or vacuum with a brush attachment, carefully remove dust from the coils. Be gentle, as bent fins reduce efficiency. For stubborn buildup, use a coil cleaning spray designed for HVAC equipment, following the product instructions carefully.
Safety First
Always unplug your dehumidifier before performing any maintenance beyond emptying the water tank. The compressor can hold residual electrical charge, and the coils may be cold enough to cause injury. Allow the unit to sit unplugged for at least an hour before accessing internal components.
Prepare for Off-Season Storage
If you won't be using your dehumidifier for an extended period, proper storage is essential:
- Run the fan-only mode (if available) for several hours to dry internal components
- Empty, clean, and thoroughly dry the water tank
- Clean the filter and all accessible components
- Wrap the power cord loosely to prevent kinking
- Store upright in a clean, dry location
- Cover with a breathable cloth to prevent dust accumulation
Troubleshooting Common Problems
Unit Runs But Doesn't Collect Water
First, check that room temperature is within the unit's operating range; compressor dehumidifiers struggle below 15°C. Inspect the filter for blockages and check that the coils aren't iced over. If frost is visible, the unit may need defrosting or there may be a refrigerant issue requiring professional service.
Unusual Noises
A rattling sound often indicates loose components or debris caught in the fan. A high-pitched whine may suggest a failing compressor or fan motor bearing. Gurgling sounds are normal and indicate refrigerant moving through the system. However, loud or persistent unusual noises warrant professional inspection.
Unit Cycles On and Off Frequently
This typically indicates the humidistat is working correctly and the target humidity has been reached. However, if it's cycling every few minutes, check that the unit isn't too close to walls or furniture restricting airflow. Ensure the target humidity isn't set unrealistically low for your conditions.
Error Codes or Lights
Modern dehumidifiers display error codes for various faults. Consult your user manual for specific meanings. Common codes indicate full tanks, filter cleaning reminders, or temperature issues. Some faults can be resolved by unplugging the unit for 10 minutes and restarting.
Maintenance Schedule Summary
- Weekly: Empty and clean water tank
- Fortnightly: Clean or check air filter
- Monthly: Clean exterior and check drainage
- Every 3-6 months: Deep clean coils
- Annually: Professional service for high-use units
When to Call a Professional
While most maintenance can be performed at home, some issues require professional attention. Contact a qualified technician if you notice refrigerant leaks (oily residue around the unit), the compressor fails to start, there's electrical burning smell, the unit trips circuit breakers, or performance doesn't improve after thorough cleaning.
For commercial or high-capacity units running continuously, consider annual professional servicing to maintain warranty coverage and ensure optimal performance. The cost of preventive maintenance is far less than emergency repairs or premature replacement.