EA Worcester Bosch
Worcester Bosch EA Error Code: Causes & Safe Fixes
EA is Worcester Bosch's best-known code — on most Greenstar models it's the general ignition/flame-detection lockout, meaning the boiler tried to light, couldn't establish or keep a flame it trusted, and shut itself down. In winter it's overwhelmingly associated with one cause owners can fix themselves: a frozen condensate pipe.
What the EA code means
During start-up a Greenstar runs a fixed sequence: fan proves airflow, gas valve opens, ignition sparks, and a sensing electrode must then confirm a stable flame within seconds. Failure at any point — no ignition, no detected flame, or a flame that vanishes — ends in the EA lockout. The code is deliberately broad: it reports that the light-and-prove sequence failed, and the engineer's job (or your condensate check's) is establishing where.
What you can safely do yourself
Work the outside-the-case list in order. One: in freezing conditions, thaw the external condensate pipe with warm water and retry — the classic winter cause of this code family. Two: verify gas is actually reaching the property — a working hob says supply is fine; a dead hob plus a meter error message says call your supplier, not a heating engineer. Three: check a prepayment meter's credit. Four: press reset once and let the boiler attempt a full ignition sequence.
What not to do: repeatedly hammer the reset button. Each attempt on a genuinely faulty burner or gas valve is the boiler protecting you by refusing; ten resets don't fix the cause, they just delay the call. And never investigate beyond the case — ignition components, gas valves and burners are legally and practically Gas Safe work.
What causes it
Seasonally ordered: in freezing weather, a frozen condensate pipe blocks the boiler's exhaust condensate route and stops ignition — the number-one winter EA by a distance. Year-round causes: gas supply interruptions (meter faults, supply work, empty prepayment credit), ageing ignition or sensing electrodes, a gas valve fault, or flue issues. A boiler that clicks repeatedly without lighting, or lights briefly then drops out, is expressing different points of failure in that chain — worth describing when you book, because the pattern narrows the diagnosis before anyone opens the case.
When to call a Gas Safe engineer
If the condensate thaw and supply checks don't clear EA, or the code returns after clearing, book a Gas Safe engineer — ignition components, gas valves and flue investigation are strictly their territory. Greenstar ignition faults are bread-and-butter work with parts on most vans, and the fix is typically a single visit. Report what the start-up attempt sounds like (clicking? brief firing?) and whether other gas appliances work; both answers shorten the visit.
Carbon monoxide is odourless and colourless. Our CO safety guide covers the symptoms, where alarms belong and the emergency response.
Frequently asked questions
What does EA mean on a Worcester Bosch boiler?
On most Greenstars it's the ignition/flame-detection lockout: the boiler couldn't establish or hold a flame it trusted during start-up. Winter's dominant cause is a frozen condensate pipe; otherwise gas supply and ignition components lead the list.
How do I reset the EA code?
Fix the cause first if it's one you can safely reach — thaw a frozen condensate pipe, restore gas supply or meter credit — then press and hold the reset button as the manual shows. One clean reset attempt is right; repeated resets against a persistent EA are not.
Why does EA appear on frosty mornings?
Because overnight frost freezes the external condensate pipe, blocking the exhaust condensate route the boiler must prove before lighting. Warm water along the pipe, then reset, resolves it — and lagging the pipe ends the annual ritual.
My Worcester clicks but won't light — is that EA?
Repeated clicking without ignition typically ends in EA and points at the spark/ignition side — electrodes, leads or the gas path. That's Gas Safe engineer work; note the sound pattern and mention it when booking.
Could it be my gas supply rather than the boiler?
Genuinely often, yes: check the hob. If other gas appliances are dead too, look at the meter for error messages or credit, and contact your supplier — a heating engineer can't fix a network or meter issue, and the visit would be wasted.
How much does fixing an ignition fault cost?
If it's condensate freezing: often nothing beyond the thaw, plus lagging the pipe to prevent repeats. Component-level fixes — electrodes, leads, sensing parts — typically land at the modest end of repair pricing once diagnosed.
Fixing causes, not symptoms
The theme running through our guides holds here too. A repair that addresses why the fault happened — the pressure that keeps dropping, the sludge that keeps returning, the condensate pipe that freezes every January — is the one you don't repeat next winter. When you book through our network, say you want the cause addressed rather than the symptom silenced; it occasionally costs a little more on the day and reliably costs less across the years you'll own the system.