- Boilers
- Gas boiler
E02
Domusa E02 on an Avanttia NG gas boiler: low water pressure
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
Domusa E02 means the water pressure in the Avanttia NG boiler has dropped below 0.5 bar and the boiler has locked out. Check the pressure on the display, raise it cold to 1 to 1.5 bar and press RESET. If it returns, call the service technician.
Safety first
Stop and check this first
- If you smell gas: Domusa says do not smoke, light flames or cause sparks, do not operate switches or electrical appliances, open doors and windows, close the main gas valve, switch the heating off, keep people out of the area and tell your gas company, following the instructions next to the meter. Call from outside the home.
- Do not run the boiler without water: Domusa warns that switching it on without water can cause serious damage. Refill first or wait for the service technician.
Safe checks you can perform
- Gas or flue gas smell near the boiler
- Pressure on the digital gauge
- Refill to 1 to 1.5 bar
- Visible leaks
- Leak, vessel and sensor by the service technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Leak search
- Do not attempt this professional task: Heating expansion vessel
- Do not attempt this professional task: Pressure sensor reading
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.
Leak search
What they doThe technician finds where the system or the boiler is losing water and checks the circuit is watertight.
They must show youwhere the loss was.
In writingthe repair and the final cold pressure.
Heating expansion vessel
What they doChecks that the expansion vessel is charged to the specification on its plate, as the annual service requires.
They must show youthe charge measured against the vessel plate.
In writingthe value and whether it was recharged.
Pressure sensor reading
What they doCompares the In 9 value in the info menu with the real pressure and checks the pressure sensor and its connection.
They must show youboth readings.
In writingthe result and whether the sensor was replaced.
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.
Gas or flue gas smell near the boiler
- Who:
- you.
- How:
- walk up without pressing switches or turning lights on and notice whether there is a smell of gas or combustion fumes.
- Result that matters:
- whether there is a smell or not.
- If there is a smell:
- do not touch the boiler and follow the gas warning on this page.
- If there is no smell:
- go on to read the pressure.
- Evidence to keep:
- the time and what you noticed.
Evidence: Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
Pressure on the digital gauge
- Who:
- you.
- How:
- with the system cold, look at the pressure value on the boiler display.
- Result that matters:
- whether it reads below 0.5 bar, between 0.5 and 1 bar or between 1 and 1.5 bar.
- If it reads below 0.5 bar:
- this confirms the lack of water E02 detects; go to the refill.
- If it reads between 1 and 1.5 bar and E02 remains:
- the pressure is in Domusa's range; call the service technician.
- Evidence to keep:
- a photo of the display with E02 and the pressure.
Evidence: Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
Refill to 1 to 1.5 bar
- Who:
- you, only if you can reach the filling valve without removing any cover; otherwise the service technician.
- How:
- slowly open the filling valve until the display reads between 1 and 1.5 bar cold, close it and press RESET.
- Result that matters:
- whether E02 clears and the pressure holds.
- If E02 returns:
- Domusa says to call the service technician if the fault does not clear.
- If you go above 2.7 bar:
- the boiler will show E03; stop filling and call the service technician.
- Evidence to keep:
- the pressure before and after and the refill date.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924) · Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
Visible leaks
- Who:
- you.
- How:
- without opening the boiler, check radiators, valves, exposed pipes and the floor under the boiler for drips or stains.
- Result that matters:
- whether you find water.
- If you find it:
- tell the service technician; Domusa names a leak as the cause of emptying.
- If you see nothing and the pressure drops again:
- the loss is hidden or inside the boiler.
- Evidence to keep:
- photos and the pressure noted daily.
Evidence: Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
Leak, vessel and sensor by the service technician
- Who:
- Domusa official service technician.
- How:
- finds the water loss, checks the heating expansion vessel and compares the pressure sensor value (In 9 in the info menu) with the real pressure.
- Result that matters:
- where the water is lost or whether the reading is false.
- If there is a leak:
- it must be repaired before refilling.
- If there is no leak and the reading does not match:
- the sensor becomes the suspect.
- Evidence to keep:
- a report with the cause and the final cold pressure.
Domusa reserves boiler servicing for staff authorised by the manufacturer. Inside are the burner, the gas valve and mains voltage parts.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924) · Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
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
- Domusa Teknik
- Product type
- Gas boiler
Known code variants
- Avanttia NG E02
- Beko dishwasher E02 flashing
- Beko dishwasher E:02
- Beko dishwasher not taking water E02
- Beko lavavajillas E:02
- Beko lavavajillas no coge agua E02
- Bosch dishwasher E02
- Bosch E02
- Bosch E02 error
- código E02 lavavajillas Bosch
- Domusa E 02
- E 02
- E02 Bosch dishwasher
- E2
- E:02
- Error E02 Domusa
- error E02 lavavajillas Bosch
- lavavajillas Beko E02 parpadea
- lavavajillas Bosch E02
What it means
On the Domusa Avanttia NG, a gas condensing boiler, a sensor measures the heating circuit pressure and shows it on the digital gauge on the display. If it falls below 0.05 MPa (0.5 bar), the control stops the burner and the pump and shows E02 flashing. Domusa explains that the lockout stops the boiler running when the system empties, through a leak or maintenance work. The correct cold pressure is 1 to 1.5 bar. Press RESET to unlock; if the fault does not clear, Domusa says to call the official service.
Warnings and stop conditions
- Criticaleditorial warning
If you smell gas: Domusa says do not smoke, light flames or cause sparks, do not operate switches or electrical appliances, open doors and windows, close the main gas valve, switch the heating off, keep people out of the area and tell your gas company, following the instructions next to the meter. Call from outside the home.
Evidence: Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
- Highsource verified
Do not run the boiler without water: Domusa warns that switching it on without water can cause serious damage. Refill first or wait for the service technician.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924)
Symptoms and causes
Probable causes · in order
- Leak in the systemCommon
Domusa names a leak as a reason for the system emptying. If you have to refill often, water is being lost somewhere.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924) · Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
- Drained for maintenancePossible
Domusa mentions maintenance work: after draining the boiler or working on a radiator, the system is left with less water unless it is refilled properly.
Evidence: Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
- Air bled from the systemPossible
Domusa warns that the pressure drops while air is purged and says to refill with the filling valve until the pressure is right.
Evidence: Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
Virtual technician
Does E02 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
Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924)
Domusa Teknik · 2023 · manual
- 2
Domusa Teknik Avanttia NG, guía rápida de funcionamiento para el usuario (CDOC001923)
Domusa Teknik · 2020 · manual
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