Asko Dryer E4 Error: Exhaust temp fault
Asko dryer E4 error is a common issue reported by Asko appliance owners. What Asko Dryer Error Code E4 Means Error code E4 on Asko dryers indicates an issue with exhaust air temperature — either the thermistor monitoring exhaust temperature has failed, or the exhaust air temperature has exceeded the safe limit due to restricted […]
Sometimes
DIY Fixable
From $150
Typical Repair Cost
45-90 min
Pro Repair Time
Quick Assessment
Answer to continue safely
Is it safe to keep using?
No. An exhaust temperature fault indicates hot air is being trapped inside the machine. Running the dryer in this state risks further overheating, lint ignition, and fire. Resolve the cause before using again.
Can I reset the code?
Yes. Allow the machine to cool fully (30 minutes) before resetting at mains. E4 will recur if the exhaust blockage or thermostat fault is not addressed.
When to stop immediately?
Stop if you notice: Any smoke from the exhaust vent or rear of the machine — power off immediately., E4 trips within 10 minutes of restart after a confirmed clear exhaust path..
Symptoms You May Notice
Exhaust duct or rear panel unusually hot to the touch
The metal exhaust connection at the back of the machine or the rear panel near the heater housing feels much hotter than during a normal cycle, suggesting air is not flowing freely through the exhaust path.
Dryer shuts down partway through cycle, restarts after cooling
The machine stops mid-cycle and displays E4, then restarts normally after a 20-minute rest — the pattern of thermal trip-cool-restart-trip-again is characteristic of an exhaust restriction fault.
Laundry takes much longer to dry than usual before fault appears
Drying times have been gradually increasing over several weeks before E4 appeared — a sign that exhaust restriction or condenser blockage has been building up progressively.
Condensation appearing on walls or ceiling near dryer in condenser models
On condenser models, a blocked condenser causes warm moist air to escape through door and panel gaps rather than being condensed internally, creating moisture on nearby surfaces.
Possible Causes
Restricted or kinked exhaust duct (vented models)
The exhaust hose has been kinked, partially crushed, or has accumulated a lint blockage along its length, trapping hot air inside the machine.
DIY PossibleBlocked condenser fins (condenser/heat-pump models)
The condenser heat exchanger on Asko T608 and DC7 models is blocked with lint and debris, preventing the heat-exchange process and causing exhaust temperature to rise.
DIY PossibleFailed exhaust temperature thermistor
The thermistor in the exhaust duct has drifted out of specification or failed, causing the control board to receive an incorrect temperature signal and trigger E4 even when airflow is normal.
Requires ProfessionalSafe Checks You Can Do
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1
Check and clear the exhaust duct (vented models)
Pull the dryer away from the wall. Disconnect the exhaust hose from the rear of the machine. Inspect the full length of the hose for kinks, crushing, or lint blockages. On rigid duct installations, use a dryer duct cleaning brush to clear the entire run from machine to exterior vent.
The exterior wall vent flap should open freely when the dryer runs — check it opens properly. Birds sometimes nest in exterior vent hoods, completely blocking the outlet.
Tools required -
2
Clean the condenser (condenser and heat-pump models)
Open the condenser access panel on the lower front of the Asko dryer. Remove the condenser unit by releasing its clips. Rinse under a running tap — water running clear through the fins indicates the condenser is clean. Allow to dry fully before refitting.
A condenser that has never been cleaned on a 3-year-old machine can be almost completely blocked. Hold it up to the light — you should be able to see through the fins when clean.
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3
Reset and run a full cotton cycle, monitoring exhaust airflow
After clearing the exhaust path, restore power and run a full cotton cycle. Hold your hand 5–10 cm from the exhaust outlet — airflow should feel strong and steady throughout. If airflow is weak, there is a remaining blockage in the duct run.
On heat-pump Asko dryers the exhaust is internal — check that the lower base tray (water collection tank) is not overflowing, as this can restrict airflow in some models.
When to Call a Professional
Contact a qualified technician if:
- E4 recurs consistently with a clean condenser and clear exhaust duct — exhaust thermistor replacement required.
- Thermistor resistance is outside specification — replacement starts from $95 on Asko T-series dryers.
- Exhaust duct run exceeds 3 metres or has more than two 90-degree bends — requires professional rerouting to meet Asko installation guidelines.
Need Professional Help?
Find qualified technicians in your area for proper diagnostics and repair.
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