Worcester Bosch Greenstar i & Si Compact Fault Codes
The Worcester Bosch Greenstar i was for years Britain's best-selling boiler — the 25i and 30i combis above all — with the Si Compact its slightly earlier sibling. Between them they hang on millions of kitchen walls, and if you have inherited a boiler with a house, odds are respectable it is one of these. They predate the current 4000/8000 platform, using Worcester's earlier control generation and its familiar code set: EA for ignition failure, CE 207 for low pressure, and the C/D/E families for fan, sensor and temperature faults. The range's enormous install base means its faults are exceptionally well understood — there is very little a Gas Safe engineer has not seen a hundred times on a 30i. This page sets out how the i and Si Compact report faults, how to reset them safely, and which codes owners actually meet, each linking through to the full diagnosis.
Where Greenstar i & Si Compact fault codes appear
Both ranges carry a simple digital display on the fascia: temperature in normal running, the fault code when locked out — sometimes with a sub-code alongside ("EA 229"). The blue-ring Worcester dial models show codes on the small central display. As ever with Worcester's two-part codes, record both parts exactly.
Resetting a Worcester Bosch Greenstar i & Si Compact
Press and hold the reset button for a few seconds until the display blanks or confirms, then release. For CE 207/low pressure, top up to 1–1.5 bar at the filling loop before resetting. These boilers tolerate the occasional reset well, but a code that returns within a day is telling you something specific — look it up rather than resetting again.
Common Greenstar i & Si Compact problems
The i and Si Compact's greatest hits: EA ignition lockouts with a strong winter bias (frozen condensate pipes on the plume-managed installs especially), gradual pressure loss producing CE 207, and — as the fleet ages — the sensor and fan codes of middle age. The 25i/30i's compact frame also runs its components warm, so pumps and fans earn their eventual replacement honestly. Almost every fault here is well-trodden ground with known parts and known prices.
Most common Greenstar i & Si Compact fault codes
- EA EA on a Worcester Bosch boiler is an ignition lockout: the boiler tried to light its… Read more →
- EA 229 The EA 229 fault code means your Worcester Bosch boiler established a flame successfully… Read more →
- CE 207 The CE 207 fault code on Worcester Bosch boilers is one of those codes where the… Read more →
- C6 The C6 fault code appears on Worcester Bosch boilers when the control system detects that… Read more →
- E9 The E9 fault code means the safety temperature limiter on your central heating flow… Read more →
- D1 The D1 fault code appears when your Worcester Bosch boiler is unhappy with the reading… Read more →
- A1 The A1 fault code on a Worcester Bosch boiler indicates that the circulation pump is not… Read more →