Blocco fiamma parassita
The 20 error code on Immergas boilers indicates blocco fiamma parassita.
Immergas 20 means: blocco fiamma parassita. The usual cause is si verifica in caso di dispersione nel circuito di rilevazione o anomalia nel controllo fiamma. A Gas Safe registered engineer should diagnose the root cause.
What Does 20 Mean
The 20 code is shown by the boiler’s control board when it detects blocco fiamma parassita. The boiler then stops instead of continuing to run in that condition: the code is the appliance reporting a problem, not proof that the boiler is broken.
| What you see on the boiler |
|---|
| The display shows 20 and the boiler stops until the fault is cleared |
Common Causes
Causes documented in 1 technical sources.
| Cause |
|---|
| Si verifica in caso di dispersione nel circuito di rilevazione o anomalia nel controllo fiamma. |
Safety Warning
20 is a gas-related fault. Never attempt to repair or adjust the gas valve, burner assembly, or flue system yourself. All gas work must be carried out by a Gas Safe registered engineer (UK) or licensed HVAC technician (US). Repeated resets after ignition failure can cause unburnt gas to accumulate inside the combustion chamber — this is a serious safety hazard. If you smell gas at any point, turn off the gas supply at the meter, open windows, leave the property, and call your gas emergency service immediately. Guasto legato al gas. Non aprire il rivestimento della caldaia e non tentare di riparare la valvola del gas, il bruciatore, il sistema di accensione o il condotto fumi. Ripristini ripetuti sono pericolosi. La diagnosi e la riparazione devono essere effettuate da tecnico qualificato.
Parts & Prices
Prices shown are indicative. Actual prices and availability vary by region.
How to Fix It
Premere il pulsante di Reset (1).
Refer to the Immergas service documentation for the detailed procedure. Only a qualified engineer should carry out these repairs.
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Affected Models
Immergas models that can display fault code 20:
| Model Family | Output Range | Frequency |
|---|---|---|
| All Immergas models | — | Possible |
Frequently Asked Questions
Premere il pulsante di Reset (1). According to the technical documentation, this is the first check on the list for 20.
20 is classified as a high-severity fault: it involves gas, combustion or flue components. Do not keep resetting the boiler and do not attempt the repair yourself — call a Gas Safe registered engineer.