Fridge
E4
The E4 error code on an AEG fridge signals a fault with the fridge compartment temperature sensor, meaning the appliance cannot accurately monitor internal temperature. It’s a moderately serious fault — your food may not be kept at a safe temperature until it’s resolved.
What does this error mean?
The E4 code indicates that the NTC (negative temperature coefficient) sensor in the fridge compartment has failed, is reading out of range, or has a broken electrical connection. The fridge’s control board relies on this sensor to regulate cooling — without a valid signal, it cannot maintain the correct temperature. In some AEG models, E4 can also appear after a prolonged power cut or a significant temperature spike inside the cabinet.
Est. repair cost
£10–£25 DIY sensor replacement; £80–£150 professional sensor repair; £150–£250 if control board replacement is needed
🔍 Likely causes
🛠️ Step-by-step fix
Reset the fridge: switch it off at the wall, wait 10 minutes, then power it back on. If E4 clears and doesn’t return within 24 hours, a temporary glitch caused it — monitor closely.
Check for ice build-up: if the back wall inside the fridge is heavily iced over, the sensor may be frozen. Defrost the fridge fully by switching it off and leaving the door open for 6–8 hours, then restart.
Locate the NTC sensor: it’s usually a small probe clipped to the back wall or evaporator cover inside the fridge compartment. Consult your AEG model’s manual or look up your model number on AEG’s UK support site (aeg.co.uk) to confirm its exact position.
Inspect the sensor wiring: look for any visible damage, kinks, or a connector that has worked loose. Press any connectors firmly back into place. Do not open any sealed electrical panels — stop here if you cannot access the connector without tools.
Test or replace the NTC sensor: replacement AEG-compatible NTC sensors typically cost £10–£25 from UK parts suppliers such as eSpares or 4ourhouse. The sensor usually unclips and plugs in without specialist tools. Replace like-for-like, matching your model number.
After any repair, run the fridge for 2–3 hours and confirm the error has gone and the compartment reaches 3–5°C before returning food to it.
📞 When to call a professional
If the error returns after a reset, defrost, and sensor replacement, the fault is likely on the main control board — this requires a qualified appliance engineer to diagnose and replace safely. Call a professional if you are uncomfortable working near the appliance’s internal wiring or if the fridge is still under AEG’s warranty (repairing it yourself may void the warranty). Tell the engineer: ‘My AEG fridge is displaying error code E4 — I believe it’s the fridge compartment NTC temperature sensor or the control board.’
⚖️ Repair or replace?
A professional repair for an E4 fault typically costs £80–£150 for a sensor replacement, or £150–£250 if the control board needs replacing. If your AEG fridge is under 8 years old and was a mid-to-high-end model (£600+), repair is almost always worthwhile. For fridges over 10 years old or budget models, replacing with a new appliance is likely better value.