EA on a Worcester Bosch means the boiler asked for a flame and the flame sensor did not detect one, so it shut down and locked out.

This is the most common Worcester Bosch fault code, and it is one of the few where there are genuinely useful checks you can do yourself before calling anyone.

What EA actually means

The boiler goes through its ignition sequence and expects to sense a flame. If it does not, it will not keep sending gas to the burner. It locks out instead.

That lockout is the boiler working correctly. Something is stopping it lighting, or stopping it proving it has lit, and it is refusing to keep trying.

What you can safely check yourself

Is the gas on? Check another gas appliance in the house, a hob is easiest. If nothing else is getting gas, the problem is the supply or the meter, not the boiler. If you are on a prepayment meter, check the credit.

Is the condensate pipe frozen? This is the usual cause in cold weather. The condensate is the white plastic pipe running out of the boiler, often to an outside drain. If it has frozen, the boiler cannot drain and will lock out. Thawing it with warm, not boiling, water poured along the outside of the pipe often clears it.

Is the flue outlet blocked? Look at the flue terminal outside. Leaves, nesting material or heavy snow across it will stop the boiler running.

If one of those was the cause, press and hold the reset button for three seconds and release it. The boiler should restart.

When to stop, and why

What causes it beyond the simple checks

Beyond those three, the usual causes are a dirty or worn ignition and flame sensing electrode assembly, a failed ignition lead, a gas valve not opening correctly, low gas pressure at the appliance, or a fault on the PCB. The service booklet runs to seventeen diagnostic steps for this code, which tells you how many things it can be.

How Vantage can help

We are Gas Safe registered under 956889 and cover Hertfordshire, Bedfordshire and Cambridgeshire, with an emergency line answered 24 hours a day. Call us on 01462 506374. See also boiler repair and boiler servicing.

Frequently asked questions

Can I reset a Worcester Bosch showing EA?

Once. If it locks out again, leave it and call a Gas Safe engineer.

Why does EA keep happening in winter?

Almost always a frozen condensate pipe. It is the single most common winter callout we get. If it happens every cold snap, the pipe run should be looked at, as it may be undersized or poorly lagged.

Is EA dangerous?

No flame detected means no gas is being burned, so the lockout itself is the safe outcome. The reason behind it still needs finding.

Related fault codes

Other Worcester Bosch codes: E9 · A1 · C6 · FA · EA 227 · all Worcester Bosch codes. The same fault on other makes: Vaillant F28 · Ideal L2 · Glow-worm F22. See also boiler not firing up and frozen condensate pipe.

In Worcester Bosch’s own words

Worcester Bosch use different code sets across their ranges and generations. The definition above is taken from the Greenstar CDi Classic service booklet. If your boiler is a different model and the code behaves differently, check the manual for your appliance or ring us and we will tell you what it means on your unit.

When to call an engineer

If the checks above have not cleared it, the next steps are engineer work and the boiler should not be reset repeatedly in the meantime. Call Vantage Plumbing and Heating on 01462 506374. We are Gas Safe registered under 956889, the line is answered by a person at any hour of any day, and you get a price before anyone starts.

Need help today?

Call and speak to a person, any hour, any day of the year. Get a fixed price quote or call 01462 506374.