UK trade guideBoiler Spares 4 min readUpdated 11 July 2026

How to Fix Vokera A01 Fault Code (No Flame At Ignition) UK

Vokera A01 means no flame at ignition. UK diagnosis, parts to order, reset sequence.

Vokera

What A01 means

Vokera A01 indicates no flame at ignition. The boiler will lock out and refuse to fire until the fault is cleared.

Do not simply reset — A01 is stored in the Vokera error log and will re-trigger within minutes if the underlying part has failed.

Diagnostic sequence

Enter service mode on the Vokera boiler and read the flow/return/DHW temperatures, fan PWM, ionisation current and pump speed.

Cross-reference against the Vokera technical manual — A01 typically points to two or three candidate parts.

  • Check wiring harness continuity to the suspect sensor before condemning it.
  • Isolate at the fused spur, discharge and re-inspect connectors.
  • Measure resistance / voltage at the PCB plug per Vokera test procedure.

Parts to have on the van

Carry a set of NTC sensors, an ignition electrode kit and a fan for Vokera — these three parts clear >70% of A01 call-outs.

Recommission

After the fix, run the Vokera boiler through a full flow test, gas rate, and combustion analysis. Log to the Benchmark book to preserve manufacturer warranty.

Frequently asked questions

Can I reset A01 without changing parts?
Only if the fault has cleared (e.g. low pressure repressurised). Persistent A01 means a hardware failure.
Which is the most common cause of Vokera A01?
On Vokera boilers, A01 most often points to the sensor or actuator matching its meaning (no flame at ignition); check wiring and connector integrity first.
Is a Gas Safe engineer required?
Yes — any works past the boiler case seal require a Gas Safe registered engineer under UK law.
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