UK trade guideBoiler Spares 5 min readUpdated 11 July 2026

How to Replace the Ignition Electrode on a Ferroli Modena HE 30C (UK)

Step-by-step UK guide to replacing the spark / ionisation electrode on a Ferroli Modena HE 30C. Part numbers, torques, commissioning.

Ferroli

The part

Renew the ignition and flame-sense electrodes on Ferroli Modena HE 30C when you get F27 / EA / L2 flame-detection faults after a clean burn.

Isolate safely

Both electrodes on Ferroli Modena HE 30C use ceramic insulators — never re-use if chipped.

Fit and commission

Set the spark gap to 3.5–4.0 mm and the ionisation gap so the tip sits 4–5 mm above the burner surface.

Recommission checklist

Refill the Ferroli Modena HE 30C to 1.2 bar cold. Bleed high-point radiators and the internal AAV.

Run a full flue-gas analysis after 15 minutes. Log the reading against the OEM commissioning envelope in the Benchmark book.

Frequently asked questions

Combined or separate?
Ferroli Modena HE 30C runs a two-electrode kit — one spark, one sense. Fit both together to avoid a second call-back.
How do I test ionisation current?
In service mode read the µA value on Ferroli Modena HE 30C. Below 4 µA at steady state means clean or replace.
Do I need to notify the manufacturer?
Only if the Ferroli Modena HE 30C is in warranty — Ferroli require log of any part swap for labour claims.
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