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Common Heat Pump Dryer Problems and How to Fix Them

Diagnose and solve the most frequent issues with heat pump dryers before calling a technician.

Even the best appliances occasionally develop issues. The good news is that many common heat pump dryer problems can be diagnosed and resolved at home without an expensive service call. This guide covers the most frequent issues we encounter, their likely causes, and step-by-step solutions you can try yourself.

Before You Start

Always disconnect the dryer from power before performing any troubleshooting that involves opening panels or checking internal components. Safety first.

Problem 1: Clothes Taking Too Long to Dry

Extended drying times are the most common complaint with heat pump dryers. While these machines naturally take longer than vented dryers, a significant increase in cycle time indicates a problem.

Possible Causes and Solutions

Clogged Lint Filter

The most common culprit is a dirty lint filter restricting airflow. Remove the filter and clean it thoroughly. If you use fabric softener, wash the filter with warm soapy water to remove any residue that may be invisible but blocking airflow.

Dirty Condenser

The heat exchanger needs regular cleaning to function efficiently. Remove the condenser (following your manual's instructions) and rinse under running water until the water runs clear. Allow it to dry completely before reinstalling.

Overloaded Drum

If clothes can't tumble freely, they won't dry evenly or efficiently. Remove some items and run a smaller load. Generally, the drum should be no more than 80% full.

High Moisture Content

If clothes are excessively wet entering the dryer, drying will take longer. Ensure your washing machine's spin cycle is completing properly and consider using a higher spin speed for items that can handle it.

Quick Check

If your dryer has an efficiency indicator or average cycle time display, compare current performance to when the machine was new. A 30% or greater increase in cycle time usually indicates maintenance is needed.

Problem 2: Clothes Come Out Still Damp

When clothes finish a cycle but remain damp, the issue could be with the dryer settings, sensors, or a maintenance problem.

Possible Causes and Solutions

Wrong Dryness Setting

Check that you're using the correct dryness level for your needs. "Iron Dry" leaves clothes slightly damp for easier ironing. Switch to "Cupboard Dry" or "Extra Dry" for items going straight to storage.

Sensor Issues

Moisture sensors can be affected by residue from fabric softeners. Locate the sensor bars (usually metal strips inside the drum near the door) and wipe them with a cloth dampened with white vinegar or rubbing alcohol.

Mixed Fabric Types

Drying heavy towels with lightweight synthetics confuses the sensors. Sort laundry by fabric weight and type for more consistent results.

Full Water Tank

If the water collection tank is full, the dryer may stop before clothes are dry. Empty the tank and restart the cycle, or connect to a continuous drain to avoid this issue.

Problem 3: Dryer Won't Start

When your dryer fails to start at all, work through these checks before assuming a major fault.

Possible Causes and Solutions

Power Supply

Check that the dryer is properly plugged in and the outlet is working. Test the outlet with another device. Check your home's circuit breaker or fuse box for tripped breakers.

Door Not Closed Properly

Most dryers won't start unless the door is fully latched. Push the door firmly until you hear it click. Check for obstructions like clothing caught in the seal.

Child Lock Activated

If the child lock is engaged, the dryer won't respond to commands. Check for a lock indicator light and consult your manual for the unlock procedure (usually holding a specific button for 3 seconds).

Delayed Start Active

The dryer may be waiting for a delayed start time. Check the display for a countdown timer and cancel if this wasn't intended.

Problem 4: Unusual Noises

Heat pump dryers make some operational noise, but new or loud sounds often indicate an issue.

Types of Noises and Their Causes

Thumping or Banging

Usually caused by an uneven load or items with heavy components (like jeans buttons) hitting the drum. Redistribute the load or remove problem items. Also check that the dryer is level—an unbalanced machine can thump during operation.

Squealing or Squeaking

May indicate worn drum bearings or a slipping belt. If the noise is new and persistent, it's best to have a technician investigate before the problem worsens.

Clicking or Rattling

Check for foreign objects in the drum or pockets that weren't emptied. Coins, keys, and other items can create significant noise. Also inspect the condenser compartment for debris.

Humming or Buzzing

Some humming is normal from the compressor. However, a loud or new buzzing sound may indicate a failing component. Monitor the sound—if it gets louder or the dryer starts malfunctioning, seek professional help.

Problem 5: Dryer Stops Mid-Cycle

A dryer that stops unexpectedly before completing its cycle requires investigation.

Possible Causes and Solutions

Full Water Tank

The most common cause. When the tank is full, the dryer stops to prevent overflow. Empty the tank and the cycle should resume or restart.

Overheating Protection

Heat pump dryers have safety systems that shut down operation if internal temperatures get too high. This usually indicates a maintenance issue—check the lint filter and condenser. Also ensure the dryer has adequate ventilation around it.

Power Interruption

A brief power fluctuation can stop the cycle. Some dryers resume automatically; others need to be restarted manually.

Repeated Shutdowns

If your dryer repeatedly stops mid-cycle after you've checked the basics, it may have a faulty component. Continuing to force operation could cause further damage. Contact a technician.

Problem 6: Error Codes

Modern heat pump dryers display error codes when they detect problems. While specific codes vary by brand, here are common categories:

Common Error Code Categories

Water Tank Errors

Indicates the tank is full or not properly inserted. Empty and reseat the tank securely.

Filter Errors

The filter is missing, not installed correctly, or needs cleaning. Remove, clean, and reinsert the filter properly.

Ventilation/Airflow Errors

Restricted airflow detected. Clean the filter, condenser, and check that nothing is blocking the machine's ventilation.

Temperature/Sensor Errors

May indicate a faulty sensor or component. Try resetting the dryer by unplugging for 5 minutes. If the error persists, professional service is needed.

Always consult your user manual for specific error code meanings for your model. Many manufacturers also offer online error code lookups.

Problem 7: Musty Smell

A musty or mildew odour from your dryer indicates moisture is lingering where it shouldn't.

Possible Causes and Solutions

  • Stale water in tank: Empty the tank after each use, especially in humid weather
  • Mould in door seal: Wipe the rubber gasket with a diluted bleach solution or vinegar
  • Damp lint in filter housing: Clean the entire filter compartment, not just the filter itself
  • Internal moisture buildup: Leave the door ajar between uses to allow air circulation

When to Call a Professional

While many issues are DIY-fixable, some problems require professional attention:

  • Electrical problems or burning smells
  • Refrigerant or compressor issues
  • Persistent error codes after basic troubleshooting
  • Mechanical failures (broken belts, bearings)
  • Any issue covered under warranty

When in doubt, it's better to call a qualified technician. Attempting complex repairs yourself could void your warranty or cause further damage. Keep your purchase documentation and warranty information accessible for reference.

JT

Written by James Thompson

James is a qualified appliance technician who has serviced thousands of dryers across Sydney. He provides technical insights and maintenance expertise for Heat Pump Dryer Australia.