- Boilers
- Gas boiler
E5
Junkers E5 on a gas boiler: flow temperature over the limit
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Junkers E5 (with cause code 218 or 332) means the primary flow temperature exceeded the limit or 110 °C. When cold, check that the pressure gauge reads 1 to 1,5 bar, open radiator valves and press reset once; if E5 returns, call the official Bosch service.
Safety first
Stop and check this first
- Never remove the outer casing or attempt repeated resets when E5 appears: internal components carry 230 V mains voltage and water that may exceed 110 °C, and only a qualified technician may open or repair the appliance.
- If you smell gas, avoid all flames or sparks, do not touch electrical switches, plugs, telephones or doorbells, turn off the main gas isolation valve at the meter or regulator, open doors and windows, warn neighbours, leave the building and call your gas supplier's emergency line and the fire service from outside.
Safe checks you can perform
- Check the pressure gauge when cold and top up to 1 to 1,5 bar
- Make sure radiator valves are open and check the flow dial
- Note the 3-digit cause code (218 or 332) and press reset once
Leave these tasks to a qualified professional
- Do not attempt this professional task: Live temperature diagnostics in the Info menu and flow NTC test
- Do not attempt this professional task: Pump test t3, air purge programme 2.2C and primary circuit check
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Live temperature diagnostics in the Info menu and flow NTC test
What they doThe technician checks info parameters i1, i2, i7, i9 (heat exchanger temperature), i10 (safety sensor) and i14 (return temperature) and tests the flow NTC sensor and its wiring at the control board.
They must show youthe live temperatures in menus i9, i10 and i14 alongside the resistance or continuity test of the flow NTC sensor.
In writingthe recorded code (E5 218 or E5 332), the sensor measurements and the part number of any original replacement fitted.
Pump test t3, air purge programme 2.2C and primary circuit check
What they doThe engineer runs component test t3 (pump test for up to 45 segundos), checks pump map parameter 2.1C and purge mode 2.2C, inspects the primary heat exchanger for blockage and checks the 0,75 bar expansion vessel pre-charge.
They must show youthe modulating pump running during test t3 and stable flow and return temperatures under heating load.
In writingthe pump curve setting in 2.1C, expansion vessel pressure and confirmation of normal circulation after purging.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Check the pressure gauge when cold and top up to 1 to 1,5 bar
- Who:
- you, with the heating system cold and without tools.
- How:
- fold down the front flap and read the pressure gauge. If the needle is below 1 bar, release the bottom panel catch, pull the blue filling lever down until the gauge reads between 1 and 1,5 bar, then release the blue lever.
- Result that matters:
- confirm the sealed heating circuit holds between 1 and 1,5 bar before attempting a reset.
- If pressure was below 1 bar:
- after topping up to 1 to 1,5 bar, check whether any radiators have cold tops and need bleeding.
- If the gauge goes above 1,5 bar while filling:
- bleed a small amount of water from a radiator until it returns to 1 to 1,5 bar.
- Evidence to keep:
- photos of the pressure gauge reading before and after topping up.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
Make sure radiator valves are open and check the flow dial
- Who:
- you, at the radiators and the boiler control panel.
- How:
- verify that thermostatic radiator valves (TRV) across the home are open and that the radiator in the room with the wall thermostat is fully open; check the heating temperature dial on the panel (adjustable from 30 to 82 °C).
- Result that matters:
- remove any external hydraulic restriction that could trap heat inside the boiler.
- If several radiator valves were shut or the dial was set to 82 °C:
- open the valves and lower the flow temperature setting.
- If all radiators were already open but stayed cold while the boiler overheated:
- suspect an internal circulation or pump issue.
- Evidence to keep:
- note of the flow temperature setting and which radiators heated up.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
Note the 3-digit cause code (218 or 332) and press reset once
- Who:
- you, using the front panel reset button once the boiler has cooled.
- How:
- write down the 3-digit cause code (218 or 332) shown under E5 while the warning triangle and blue LED flash. After letting the unit cool, press the reset key once (do not press the blue diagnostic light) until Reset and the checkmark appear.
- Result that matters:
- see whether the boiler clears the lockout and runs normally after cooling.
- If E5 clears and heating runs smoothly:
- monitor the pressure gauge over the next few days to rule out leaks.
- If E5 returns and the blue light keeps flashing:
- do not press reset again; switch the boiler to 0 and call an authorised technician.
- Evidence to keep:
- photo of the display showing E5 and the 3-digit cause number.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- Boilers
- Brand
- Junkers
- Product type
- Gas boiler
Known code variants
- aire acondicionado Daikin E5
- caldera Junkers E5
- Cerapur E5
- Cerapur Excellence Compact E5
- climatisation Daikin E5
- climatizzatore Daikin E5
- code erreur E5 Daikin
- codice E5 Daikin
- código E5 Daikin
- Daikin AC E5
- Daikin E5
- Daikin error E5
- Daikin Fehler E5
- Daikin Fehlercode E5
- E05
- E 5
- E5 218
- E5 332
- error E5 aire Samsung
- error E5 Daikin
- Error E5 Junkers
- error E5 lavavajillas Smeg
- errore E5 Daikin
- Gree E5
- Junkers boiler E5
- Junkers E5
- Klimaanlage Daikin E5
- lavavajillas Smeg no carga agua E5
- panne E5 Daikin
- Samsung AC E5 error
- Samsung E5
- Smeg dishwasher E5
- Smeg dishwasher error E5
- Smeg dishwasher not filling E5
- Smeg lavavajillas E5
- Smeg LVFABCR3 E5
What it means
In the official Spanish technical manual for the Junkers Cerapur Excellence Compact (the manufacturer documentation for this model is in Spanish), lockout code E5 pairs with cause code 218 (flow temperature too high) or 332 (flow sensor / primary heat exchanger exceeded 110 °C), both cleared with the reset button. The code alone never proves that the flow NTC sensor or pump has failed: system pressure below 1 bar, closed thermostatic radiator valves (TRV) or trapped air can trap heat inside the primary exchanger and trigger the exact same lockout.
Warnings and stop conditions
- Higheditorial warning
Never remove the outer casing or attempt repeated resets when E5 appears: internal components carry 230 V mains voltage and water that may exceed 110 °C, and only a qualified technician may open or repair the appliance.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
- Highsource verified
If you smell gas, avoid all flames or sparks, do not touch electrical switches, plugs, telephones or doorbells, turn off the main gas isolation valve at the meter or regulator, open doors and windows, warn neighbours, leave the building and call your gas supplier's emergency line and the fire service from outside.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
Symptoms and causes
Probable causes · in order
- Low system water pressure or air trapped in the primary circuitCommon
When cold pressure drops below 1 bar or air pockets remain after filling, water cannot carry heat away from the aluminium-silicon heat exchanger, triggering E5 with cause 218 or 332.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
- Restricted circulation from closed thermostatic radiator valvesPossible
Closing too many radiator TRVs at once, or closing the radiator in the reference room where the room thermostat is installed, blocks flow and causes rapid primary overheating.
Evidence: Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación · Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
- Modulating circulation pump seized, air-locked or unpoweredPossible
If the boiler pump stalls, runs with air or loses drive from the control board, water sits still in the primary block and quickly climbs past the 110 °C threshold of cause 332.
Evidence: Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
- Faulty primary flow NTC temperature sensor or harness connectionLess common
An electrical drift or damaged lead on the primary flow NTC sensor can report a false temperature above 110 °C to the control unit even when water circulation is normal.
Evidence: Junkers Cerapur Excellence Compact ZWB...A..., instrucciones de instalación y manejo para el técnico (6 720 820 575)
Virtual technician
Does E5 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Junkers Cerapur Excellence Compact, instrucciones de uso de la caldera mural a gas de condensación
Junkers (Bosch Termotecnia) · 2019 · manual
- 2
Junkers (Bosch Termotecnia) · 2019 · manual
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