Symptoms
- Cycles take noticeably longer than a standard vented dryer
- Clothes come out only lukewarm, which is normal but confusing
- Drying performance has gotten worse over recent months
- Error messages related to filters or the heat exchanger
Likely causes
- CommonNormal heat pump operation, which runs cooler and longer by designHeat pump dryers use lower temperatures and longer cycles to be more energy efficient, which is expected behavior, not a fault.
- CommonDirty lint filters (often two-stage on heat pump models)Heat pump dryers often have multiple filters that need more frequent cleaning than standard dryers.
- CommonDirty heat exchanger/condenser coilDust and lint on the heat exchanger fins reduce the heat pump's efficiency significantly.
- PossibleOverloading the drumHeat pump dryers are more sensitive to overloading than vented dryers due to lower drying power.
- Less commonRefrigerant circuit fault in the heat pump systemA failing compressor or refrigerant leak in the heat pump unit reduces heating capacity.
What to do
- Confirm whether long cycle times are simply normal for your specific heat pump model by checking the manual's expected cycle length.
- Clean all lint filters as specified, which is often more frequent than on vented dryers, sometimes after every load.
- Locate and clean the heat exchanger/condenser coil per your manual, usually accessible behind a lower panel.
- Reduce load size somewhat compared to what you'd put in a vented dryer.
- Ensure the room the dryer is in isn't excessively cold, since heat pump efficiency drops in cold spaces.
- Run a cycle after cleaning the filters and heat exchanger to see if drying time improves.
- If performance stays poor after thorough cleaning, have a technician check the refrigerant circuit and compressor.
Tools and parts
- Vacuum or soft brush
Heat pump dryer condenser filterSearch: “heat pump dryer condenser filter”
When to call a pro
If cleaning filters and the heat exchanger doesn't improve performance, a technician trained in heat pump appliances should check the refrigerant circuit.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.