Applies to: automatic machines (E6, E8, ENA, S8, J8, Z10, GIGA).
How to fix Error 4
- Unplug and let the machine cool for an hour.
- Run a full descale following Jura's manual. A technician source says scale on the thermoblock changes how quickly the sensor sees heat.
- If it returns, a qualified technician would inspect the sensor cable and contacts and replace the sensor. If it overheats again with a new sensor, the power board is the next suspect. Do not open the machine yourself.
When to stop and call a repairer
A heater that will not switch off is a fire risk. Do not leave the machine powered unattended while this code is active.
What it costs
| Parts | Part prices are not published by the manufacturer. Ask a parts supplier or service centre for a current price. |
|---|---|
| Service | Service prices are not published by the manufacturer. Ask an authorised service centre, and an independent espresso repairer, for a quote. |
| Worth repairing? | Get a quote first, especially if the power board is implicated. |
Beyond the fix
Tips and tricks
- Unplug the machine for a few minutes, then restart, as a UK dealer advises for thermoblock codes. If it was stored somewhere cold, let it reach room temperature first, as the German table suggests.repair guide
- Keep up with descaling prompts. A parts seller lists a scaled steam thermoblock among causes on this code.repair guide
- If it returns, a technician checks the sensor, the thermal fuse and the power board. A UK dealer says a faulty power board will blow replacement fuses again.repair guide
Common mistakes
- Replacing the fuse cords without finding why they blew. The UK dealer says a faulty power board will blow them again.
- Reading a cold-room Error 4 as a hard fault. The German table lists too cold as a possible cause.
Easily confused with
- Error 3 is the steam thermoblock too low; Error 2 is the coffee-side high reading in the same table.
Further reading
Questions
What does Error 4 mean on the Jura?
Steam thermoblock overheating or a defective sensor. The steam thermoblock got hotter than the board expected, according to third-party technician tables (Jura's manuals do not define this code). Technician sources point to a sensor that under-reads (scale insulation, corroded contacts) or a power board that did not cut the heater.
Can I fix Error 4 myself?
DIY difficulty: hard. Unplug and let the machine cool for an hour. Run a full descale following Jura's manual. A technician source says scale on the thermoblock changes how quickly the sensor sees heat.
How much does it cost to fix Error 4?
Part prices are not published by the manufacturer. Ask a parts supplier or service centre for a current price. Service prices are not published by the manufacturer. Ask an authorised service centre, and an independent espresso repairer, for a quote.
Is it worth repairing?
Get a quote first, especially if the power board is implicated.
When does Error 4 typically show up?
Juras report Error 4 any. That timing is a useful clue when narrowing the cause.
Can I keep using the machine with Error 4 showing?
Treat it as a stop-using signal: Error 4 marks a fault that can damage the machine (or worse) if you keep running it. Do the safe first steps below, then stop.
Will Error 4 clear on its own?
Rarely. A reset or power cycle is worth one try, but Error 4 with a "hard" difficulty rating almost always means a failed component that has to be replaced.
How long does the repair take?
This one is a bench repair for most owners — the teardown, test and reassembly are the bulk of the work, not the part itself.