- Boilers
- Gas boiler
10
Immergas 10 on a gas boiler: water pressure too low
Risk level
Medium
Proceed carefully and stop if the check is unclear.
Urgency
Medium
Quick answer
Immergas 10 means the heating water pressure is not enough to run correctly. With the system cold, the gauge should read 1 to 1.2 bar; if it is below 1 bar, top up with the filling tap and close it again.
Safety first
Stop and check this first
- If you smell gas: Immergas says to close the meter or main gas tap and, if you can, the boiler's gas tap, open doors and windows, use no naked flames, do not smoke and do not touch switches, sockets, doorbells or phones. Leave the home and call your gas distributor's emergency number from the street.
- Do not open the filling tap if the mains water is below 2.5 bar: Immergas warns that heating water could contaminate the domestic hot water cylinder and cause health problems.
Safe checks you can perform
- Gauge reading when cold
- Top up with the filling tap
- How often the pressure drops
- Leaks, expansion vessel and safety valve by the technician
Leave these tasks to a qualified professional
- Do not attempt this professional task: Water leak search
- Do not attempt this professional task: Expansion vessel charge
- Do not attempt this professional task: Safety valve and pressure switch
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.
Water leak search
What they doThe technician checks for water leaks and corrosion at the boiler fittings, as Immergas asks at maintenance, and inspects the system.
They must show youwhere the leak was.
In writingthe repair made and the final cold pressure.
Expansion vessel charge
What they doWith the system pressure released to zero, the technician checks that the heating expansion vessel charge is 1.0 bar, as Immergas states.
They must show youthe charge measured on the vessel.
In writingthe value measured and, if it was recharged or replaced, why.
Safety valve and pressure switch
What they doThe technician checks the water safety valve outlet is not blocked and that the system pressure switch has not been tampered with or bridged.
They must show youthe state of the valve and pressure switch.
In writingwhat was checked and any part replaced with the reason.
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.
Gauge reading when cold
- Who:
- you.
- How:
- with the system cold, read the needle on the boiler gauge. Immergas asks for a value between 1 and 1.2 bar.
- Result that matters:
- whether the pressure is below 1 bar.
- If it is below:
- top up (next check).
- If it is 1 to 1.2 bar and E10 stays:
- tell the technician; the boiler is detecting something the gauge does not explain.
- Evidence to keep:
- a dated photo of the gauge.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Top up with the filling tap
- Who:
- you.
- How:
- Immergas asks you to first confirm the mains water pressure is at least 2.5 bar; if not, do not open the filling tap. Slowly open the filling tap at the bottom of the boiler to 1 to 1.2 bar cold and close it when done.
- Result that matters:
- whether the pressure stays in range and E10 clears.
- If it clears:
- note the date and watch the gauge.
- If you overfill and it nears 3 bar:
- release water through the relief valve back to 1 bar or call qualified staff, as Immergas says.
- Evidence to keep:
- photos of the gauge before and after.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
How often the pressure drops
- Who:
- you.
- How:
- note every time you top up and how far the pressure fell.
- Result that matters:
- whether the drops are frequent.
- If they are:
- Immergas asks for qualified staff to repair the likely leak.
- If it happened once after bleeding or draining:
- it fits that job.
- Evidence to keep:
- a list of dates and gauge readings.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Leaks, expansion vessel and safety valve by the technician
- Who:
- technician from an authorised company.
- How:
- looks for water leaks, checks the expansion vessel charge, the safety valve outlet and the system pressure switch.
- Result that matters:
- why the pressure falls.
- If there is a leak:
- it is repaired before refilling.
- If the expansion vessel or the valve is at fault:
- it is corrected.
- Evidence to keep:
- a job sheet with what was found and repaired.
Opening the boiler, the expansion vessel, the safety valve and the pressure switch are work for professionally qualified staff, according to Immergas.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
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
- Immergas
- Product type
- Gas boiler
Known code variants
- 10
- Ariston Velis 10
- calentador Rinnai 10
- código 10 Rinnai
- E10
- Er 10
- Error 10 Immergas
- error 10 Rinnai
- Immergas E10
- Rinnai 10
- Rinnai 10 tankless
- Rinnai code 10
- Rinnai code 10 water heater
- Rinnai error 10
- Velis error 10
- Victrix 10
- Victrix E10
What it means
On the Victrix Zeus 25/32, E10 is insufficient system pressure: the water pressure detected in the heating circuit does not guarantee correct operation. Immergas asks you to check on the gauge that it is between 1 and 1.2 bar when cold and restore it if needed. If the drops are frequent, a likely leak must be repaired. The code does not say why the pressure fell: bleeding, a leak or the safety valve opening all give the same warning.
Warnings and stop conditions
- Criticaleditorial warning
If you smell gas: Immergas says to close the meter or main gas tap and, if you can, the boiler's gas tap, open doors and windows, use no naked flames, do not smoke and do not touch switches, sockets, doorbells or phones. Leave the home and call your gas distributor's emergency number from the street.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Highsource verified
Do not open the filling tap if the mains water is below 2.5 bar: Immergas warns that heating water could contaminate the domestic hot water cylinder and cause health problems.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Symptoms and causes
Probable causes · in order
- Water leak in the systemCommon
Fits if the pressure keeps dropping. Immergas says frequent drops point to a likely leak in the system that must be repaired.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Water lost when bleeding or drainingPossible
Fits if E10 appears after bleeding radiators or draining part of the system and does not return after topping up. Immergas asks for the pressure to be checked after filling and bleeding.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
- Discharge through the safety valvePossible
Fits if you saw the pressure near 3 bar before. Immergas warns that at those values the safety valve may open and release water.
Evidence: Immergas Victrix Zeus 25/32, instrucciones y advertencias para instalador, usuario y mantenimiento (1.042022SPA)
Virtual technician
Does 10 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
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