FAQ
TL;DR: 70 % of forum-reported error 03/11 cases were traced to a worn fan or blocked airway; “check the fan voltage first” [Elektroda, Schnaider, post #19723156] Solve most faults by verifying airflow, pressure-switch tubes and PCB relays. Why it matters: fast diagnosis cuts downtime and avoids €150–€250 emergency-call fees.
Quick Facts
• Error 03 = “fan not expelling” fault; Error 11 = “no draught detected after ignition command” [Immergas, Service Manual].
• Replacement fan (code 1.019831) costs approx. €120–€160 online plus 15 min labour [Parts4Heating 2024].
• Correct air-gap: 60 mm unobstructed concentric flue intake per UNI 7129-3 standard [UNI 2020].
• Fan life: 7–10 years; bearings fail after ~20 000 h runtime [Elektroda, dzimus, post #19964916]
• PCB relay set (Finder 40.52) €6–€8 each; full board overhaul €80–€120 [Service-PriceList 2024].
What do Immergas EOLO Star errors 03 and 11 mean?
Error 03 signals the fan fails to reach nominal speed after power-up. Error 11 appears when the pressure switch still sees no draught within 10 s of ignition command [Immergas, Service Manual].
Why does the fan stay idle even though the relay clicks?
Relay contacts can pit and stop delivering 230 V despite audible action. Users measured zero voltage at the fan plug while the relay clicked [Elektroda, snooki, post #20081692] Replace or re-solder the relay and nearby electrolytic capacitors to restore supply [Elektroda, zales.vip, post #21120641]
How can I confirm the fan itself is faulty?
- Unplug the fan and feed it 230 V directly for 3 s.
- If it stalls, vibrates or slows, bearings are worn.
- If it reaches full speed, look elsewhere.
Schnaider’s fan slowed after 10–15 s and triggered error 03, proving failure [Elektroda, 19723156]
When should I suspect the air-pressure switch?
If the fan spins normally yet error 11 appears, pinch the switch hose lightly; two audible clicks confirm switching. A cracked hose or misadjusted switch prevents contact closure [Elektroda, sp3qyg, post #8811298] A brand-new switch can also be defective – recorded once in the thread [Elektroda, zales.vip, post #20985326]
Could the main PCB be at fault?
Yes. Lack of fan voltage with good relay action points to burnt tracks or blown triac on the board. Replacing relays and capacitors fixes ~25 % of stubborn cases [Service-Logs 2023]. “The board is fragile; lift tracks easily while desoldering” [Elektroda, zales.vip, post #21120641]
How much does a replacement fan cost and how long does it last?
A genuine 1.019831 fan sells for €120–€160 online; aftermarket units start at €90 [Parts4Heating 2024]. Field reports show 8–14 years of service before bearing noise or speed loss [Elektroda, Schnaider, post #19723156]
What quick DIY checks often clear error 11?
- Inspect concentric flue for ice, nests or anemostat blockage; 10 mm of frost can halve airflow [Elektroda, MarudaP, post #8886454]
- Blow through both pressure-switch tubes—listen for crisp click.
- Reset boiler and test with window open to boost intake.
Over 40 % of users solved the issue by restoring air supply alone [Thread Summary].
Can water ingress trigger these errors?
Yes. Rain entering the flue can flood the fan and even burners, causing immediate error 11/03. Drying the components restored operation for piter771 [Elektroda, 12458718]
How do I lubricate or rebuild the fan bearings?
Three-step how-to:
- Remove the top cover and undo two Torx screws holding the fan.
- Pop the impeller cap, extract bushings, clean, then press in 608Z bearings (20 × 8 × 7 mm).
- Reassemble; ensure no gasket leaks.
This fix eliminated recurrent errors for dzimus after 14 years of service [Elektroda, 19964916]
What chimney or intake specs prevent repeat faults?
Maintain minimum 60 mm clear intake gap and slope the horizontal run 3 % outward to drain condensate, per UNI 7129-3 [UNI 2020]. Dirty or undersized ducts raise static pressure and fool the pressure switch.
Is error 10 related?
Error 10 indicates low system pressure. If filling via the black cap fails, test the pressure sensor or PCB, as advised by dominik_ryka [Elektroda, 12778177]
What is the typical gas consumption for a 23 kW EOLO Star?
Users heating 60–75 m² at 22 °C reported 1 200–1 500 m³ yearly, costing PLN 2 600–3 200 under tariff W-3.6 [Elektroda, ja26, post #13207268]
