Truma Cooler
The Truma Cooler is a range of portable compressor-based cool boxes designed for cooling and freezing food in caravans and motorhomes. It can be powered via 100-240 V AC, 12/24 V DC, or an auxiliary battery, and supports Bluetooth smartphone control via the Truma Cooler App.
View official manual on manufacturer's site ↗Technical Specifications
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
E0 | Temperature sensor (NTC) defective | — | Contact Truma Service. | Professional Intervention Required |
E1 | Low voltage / Battery discharge prevention has been triggered | — | Check power supply, ensure proper cable cross-section (min 1.5 mm² up to 2m, min 2.5 mm² over 2m), or reduce battery discharge prevention setting (e.g., ME or LO). | DIY Safe |
E2 | Fan problem | — | The fan has failed and needs replacing by an expert. | Professional Intervention Required |
E2 (2 x blinking) | Fan problem | — | The fan has failed and needs replacing by a specialist. | Professional Intervention Required |
E3 | Compressor starting problem | — | Unplug the cool box, leave it for 10 minutes and check the power supply. If the compressor has failed, have an expert replace it. | DIY Check / Tech Fallback |
E3 (3 x blinking) | Compressor starting problem | — | Disconnect the cooler, leave it to rest for 10 minutes, then check the power supply. If that doesn't fix it, the compressor has failed and a specialist must replace it. | DIY Check / Tech Fallback |
E4 | Low fan speed | — | Put fewer items in, move it somewhere cooler, clear the air vents so it can breathe, or replace the fan if it has failed. | DIY Check / Tech Fallback |
E4 (4 x blinking) | Low fan speed | — | Take some items out, move the cooler somewhere cooler, clear the vents so it's properly ventilated, or have a specialist replace the fan. | DIY Check / Tech Fallback |
E5 | Portable fridge/freezer overheated | — | Move it somewhere cooler, clear the air vents so there's enough ventilation, or replace the fan if it has failed. | DIY Check / Tech Fallback |
E0 | Defective temperature sensor (NTC) | — | Contact the Truma service center. | Professional Intervention Required |
E1 | Undervoltage / Battery discharge protection triggered | — | Check power supply, ensure proper cable cross-section (min. 1.5 mm² or 2.5 mm² for distances over 2m), or reduce battery protection level (ME or LO). | DIY Safe |
E3 | Compressor startup problem | — | Disconnect the device, let it rest for 10 minutes, check power supply, or have the compressor replaced by a specialist if defective. | DIY Check / Tech Fallback |
E5 | Device overheated | — | Move device to a cooler location, clean ventilation openings, ensure compressor is adequately ventilated, or replace defective fan. | DIY Safe |
E1 (1 x blinking) | Low voltage / Battery discharge protection activated | — | Check power supply (try another power source/outlet). Ensure cable between battery and cooler is at least 1.5 mm² (or 2.5 mm² if distance is greater than 2 m). Lower battery discharge protection setting (e.g., ME or LO). | DIY Safe |
E5 (5 x blinking) | Cooler overheated | — | Relocate the cooler to a cooler place, clean ventilation openings/ensure adequate ventilation, or have the fan replaced by a specialist. | DIY Check / Tech Fallback |
Frequently Asked Questions
Q: How do I switch on the Truma Cooler?
Connect it to its power supply. If it doesn't start straight away, press the On/Off button.
Q: What should I do if the display or electronic control fails?
You can set the emergency override switch on the front side to EMERGENCY OVERRIDE so the cool box runs in emergency mode with full cooling power.
Q: Can I connect multiple cool boxes together?
No - don't link portable fridge/freezers to each other electrically. Each one needs its own separate power supply.
Q: How do I turn on Emergency Override mode?
If there are issues with the display or electronic control unit, set the emergency switch on the connection panel to 'EMERGENCY OVERRIDE' to operate the device continuously at full cooling capacity.
Q: What should I do to prevent children from becoming trapped in the cooler before disposal?
When you get rid of it, take off the lid(s) and put the wire baskets in, so a child can't climb in and get shut inside.
Q: What power sources can be used to run the Truma Cooler?
The cooler can be powered by a 100 - 240 V AC mains supply, a 12/24 V DC vehicle power grid, or a 12/24 V supply battery.
Q: How do I reverse or remove the lid on compatible models?
Swing the lid open to its stop, then push it beyond the stop and lift it off. To refit it, hold it upright over the stainless steel pins either side and press down until both hinges click into place.