- Boilers
- Gas boiler
E84
Domusa E84 on a gas boiler: gas inlet pressure error
Risk level
High
Professional inspection is recommended.
Urgency
High
Quick answer
Domusa E84 flags a gas inlet pressure error on the Avanttia NG. Check that gas is reaching the boiler, press RESET once only and, if the code returns, stop trying and call the official Domusa SAT.
Safety first
Stop and check this first
- On a smell of gas do not operate anything electrical or strike a flame: ventilate by opening doors and windows, close the main valve if you can reach it safely, move away and notify the gas company or 112.
- Do not open the boiler, touch the gas valve or its pressure test points, or change the inlet pressure: this is work for authorised staff.
- A single RESET is the most that is reasonable. If E84 returns, do not force more start attempts and wait for the technician.
Safe checks you can perform
- Confirm gas is reaching the boiler
- Press RESET once
- The SAT measures the gas inlet pressure
- The SAT reviews the error history
Leave these tasks to a qualified professional
- Do not attempt this professional task: Gas pressure measurement with the boiler running
- Do not attempt this professional task: Gas valve and control review
- Do not attempt this professional task: Notice to your gas distributor or propane supplier
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.
Gas pressure measurement with the boiler running
What they doAn authorised professional measures the inlet pressure and compares it with the manual figure for the gas your boiler runs on.
They must show youthe reading in mbar with the boiler firing and the gas type it was compared against.
In writingthe measured value, the reference pressure and the conclusion on supply or boiler.
Gas valve and control review
What they doIf the inlet pressure is correct, the Domusa SAT reviews the gas valve circuit and the boiler's pressure reading.
They must show youthe pressure measurement that ruled out the supply before anything was touched.
In writingwhich component was checked or replaced and why.
Notice to your gas distributor or propane supplier
What they doIf the low pressure comes from the network or the tank, the distributor or supplier has to correct it, not the boiler.
They must show youthe ticket or reference number of the call to the supplier.
In writingthe date of the call and what was checked on the supply.
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.
Confirm gas is reaching the boiler
- Who:
- you, no tools.
- How:
- See that the gas valve at the boiler and the one at the meter are open, and on a propane system ask your supplier to confirm the tank holds gas and has been purged. Never test with a flame or matches.
- Result that matters:
- What counts is whether a closed valve, a cut or an empty tank explains the lack of pressure.
- If you find a closed valve and do not know why, do not force it and ask the SAT before reopening it.
- If everything looks open and supplied, go on to the single RESET in the next step.
- Evidence to keep:
- a note of which valves were open or closed and, for propane, the call to the supplier.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
Press RESET once
- Who:
- you, no tools.
- How:
- Press the panel RESET button one time, which is what the alarm table asks for, and watch whether the boiler lights.
- Result that matters:
- What matters is whether E84 clears and the burner lights normally.
- If the boiler lights and no code shows, note the time in case it happens again.
- If E84 appears again, do not repeat RESET:
- stop using the boiler and call the official Domusa SAT.
- Evidence to keep:
- the time of the fault and any other codes shown at the same moment.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
The SAT measures the gas inlet pressure
- Who:
- official Domusa SAT or an authorised gas installer, with measuring equipment.
- How:
- Measures at the inlet test point with the boiler firing and compares it with the 20 mbar for natural gas (G20) or 37 mbar for LPG (G31) in the installation manual.
- Result that matters:
- The reading decides whether the fault sits in the supply or inside the boiler.
- If the inlet pressure falls short of the manual value, it is corrected on the installation or with the distributor and the test is repeated.
- If the pressure is right and E84 continues, the technician moves on to the gas valve and the boiler control.
- Evidence to keep:
- the pressure reading in mbar with the gas type noted.
The work is done at the gas test point while the boiler runs: authorised staff only, with a tightness check afterwards.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924)
The SAT reviews the error history
- Who:
- an official Domusa SAT technician, reading the boiler panel.
- How:
- Reads the last 10 errors in the Info Menu and sees whether E84 arrived together with E94, which the table describes as low gas pressure or recirculation of gas.
- Result that matters:
- Knowing which codes travel with E84 helps separate a supply problem from a combustion one.
- If E94 or gas valve errors show in the history, the review widens to that area.
- If E84 appears alone, go back to the pressure reading and the supply.
- Evidence to keep:
- a photo or list of the error history.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924) · Domusa Teknik Avanttia NG operation user guide (CDOC001980)
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 E84
- caldera Domusa E84
- Domusa boiler E84
- Domusa E 84
- Domusa E84 error
- Domusa gas inlet pressure error
- Domusa presión de entrada de gas
- E 84
- Error E84 Domusa
What it means
The Avanttia NG alarm table describes E84 as a gas inlet pressure error and says to press RESET and contact the SAT if the error persists. It concerns the pressure at which gas reaches the boiler, not one specific part, so the code alone does not prove that the gas valve, a sensor or the board is faulty. Inlet pressure is measured on the installation with proper equipment, and only authorised staff do that. The installation manual used for the figures is in Spanish.
Warnings and stop conditions
- Higheditorial warning
On a smell of gas do not operate anything electrical or strike a flame: ventilate by opening doors and windows, close the main valve if you can reach it safely, move away and notify the gas company or 112.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
- Higheditorial warning
Do not open the boiler, touch the gas valve or its pressure test points, or change the inlet pressure: this is work for authorised staff.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924)
- Mediumeditorial warning
A single RESET is the most that is reasonable. If E84 returns, do not force more start attempts and wait for the technician.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
Symptoms and causes
Probable causes · in order
- Valve shut or supply interruptedCommon
A closed gas valve or an interruption in the supply would leave the boiler without the inlet pressure it expects to receive.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
- Empty or unpurged propane tankPossible
On propane installations the guide warns of ignition problems when the tank has not been purged properly, and sends you to whoever fills it.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
- Network or regulator pressure off targetPossible
The installation manual (Spanish) sets 20 mbar for natural gas (G20) and 37 mbar for LPG (G31) as inlet pressure. Another value in the network or the regulator can trigger the alarm.
Evidence: Domusa Teknik Avanttia NG, instrucciones de instalación y funcionamiento (CDOC001924)
- Sensor, gas valve or electronic controlLess common
If the real pressure is correct and E84 keeps appearing, the fault may be in the reading or in the control. Only the SAT can test that, not you.
Evidence: Domusa Teknik Avanttia NG operation user guide (CDOC001980)
Virtual technician
Does E84 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 operation user guide (CDOC001980)
Domusa Teknik · 2020 · manual
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