Skip to the entry
Boiler Look-Up
Subjects

Look-up › Fault codes by maker

Worcester Bosch display codes

Checked against its sources: Updated

Worcester Bosch fault codes defined in the user manuals read are few: EA, 1017 and LoPr, plus some status displays on the Greenstar 24/28.1567 The user manuals read don't list other numbers.

Covers
Worcester Bosch boilers named below; gas unless stated
You
Read the display, top up pressure as your manual says, check outlets only if safe, and reset once by your model's method.
A professional
Any other code, any fault that persists, and anything inside the case. Worcester's manuals say only a competent engineer can remove it.

1 Codes the user manuals define

Worcester Bosch codes, read from the user documents
Code or displayWhat the Worcester manual saysWhich manual, pageWhat the Worcester manual lets you do
EA, flashingNo gas or low gas supply pressure, blocked condensate outlet, or blocked flueGreenstar i ErP (2015/03) p241; Si Compact ErP (2014/09) p172; i System Compact (2013/05) p173; CDi Compact ErP (2014/09) p154Contact your gas supplier. If it is safe to do so, check the condensate and flue outlets for blockage or damage: look from the ground, no ladders, don't touch the flue
Fault - 1017"System pressure too low", shown in the manual's figuresGreenstar 4000 (2020/09) pp7, 95Top up by that manual's method until the display says the pressure is OK
LoPrAlternates with the actual pressure when it is too low (0.2 bar or less); system out of operationGreenstar 8000 Life (2021/05) p66Top up the heating water
InInspection dueGreenstar 24/28 (2012/05) p207No step printed; speak to whoever services the boiler
LoButton lock activeGreenstar 24/28 p207No step printed
Trap-filling symbol (a picture, not letters)Trap filling function activeGreenstar 24/28 p207No step printed
Air-purge symbol (a picture)Air purge function activeGreenstar 24/28 p207No step printed
Rapid-rise symbol (a picture)Heating flow temperature rising too fast; heating disabled for two minutesGreenstar 24/28 p207No step printed

2 Numbers shown only as examples

Several manuals print a number only to show what a code looks like, with no meaning: 232 (4000, 8000 Life, 8000 Style, 8000+), 214 (2000), 227 beside EA (i ErP, CDi Compact), and "224 Temp" in a figure (i ErP).56814 They aren't defined here either. Quote the number to Worcester or the engineer. The Greenstar 12i/24i System (2006 issue) has no display code: the blue mains light flashes at different speeds, and Worcester asks for the sequence.10

3 How the reset works on each family

Reset method printed for each Worcester family
BoilerPrinted methodManual, page
Greenstar 4000, 8000 Style, 8000+Press the two keys pictured until "Reset" displays4000 p165; Style p1311; 8000+ p1112
Greenstar 8000 LifePress the two keys together until the fault disappearsp116
Worcester 2000Switch off and on, or press the two arrows at once until the symbols clearp118
Greenstar i ErPPress reset briefly, once; some codes can't be clearedp251
Greenstar i System CompactPress reset for about one secondp183
CDi Compact ErPPress reset; no duration printedp164
Greenstar 24/28Press reset until a symbol displaysp197

No document read gives a maximum number of resets, so try once, and contact Worcester or an engineer if the fault persists.

4 Pressure, cold weather and gas

Top-up figures differ by model, so follow your manual's pressure figures. For ice in the condensate pipe, most of these guides allow thawing at ground level only; see frozen condensate pipe. If you smell gas, follow the site's gas wording.

5 What wasn't covered

Only the manuals named here were read, several of them by searching for fault passages and not page by page. Worcester's other user guides, including CDi Classic, Highflow and Junior, weren't read. One older oil guide describes a lockout button behind the front cover and warns against repeated restarts; that is oil-specific, and isn't given here as a step.9

Sources

  1. Worcester Greenstar i ErP 25i/30i user instructions, 6 720 806 946 (2015/03), Worcester Bosch read 3 November 2026.
  2. Worcester Greenstar Si Compact ErP user instructions, 6 720 813 279 (2014/09), Worcester Bosch read 3 November 2026.
  3. Worcester Greenstar i System Compact 27i/30i user instructions, 6 720 807 727 (2013/05), Worcester Bosch read 3 November 2026.
  4. Worcester Greenstar CDi Compact ErP user instructions, 6 720 813 277 (2014/09), Worcester Bosch read 3 November 2026.
  5. Worcester Greenstar 4000 GR4700iW C user instructions, 6 720 891 170 (2020/09), Worcester Bosch read 3 November 2026.
  6. Worcester Greenstar 8000 Life GR8300iW user instructions, 6720883872 (2021/05), Worcester Bosch read 3 November 2026.
  7. Worcester Greenstar 24/28 user instructions, 6 720 801 019 (2012/05), Worcester Bosch read 3 November 2026.
  8. Worcester 2000 combi user instructions, 6 721 814 552 (2019/09), Worcester Bosch read 3 November 2026.
  9. Worcester Greenstar HE Oil 12/22 user instructions, 8716130071, issue date not confirmed, p7, Worcester Bosch read 3 November 2026.
  10. Worcester Greenstar 12i/24i System user instructions, 8 716 107 376b (06/06), p10, Worcester Bosch read 3 November 2026.
  11. Worcester Greenstar 8000 Style GR8700iW user instructions, 6720883871 (2021/05), Worcester Bosch read 3 November 2026.
  12. Worcester Greenstar 8000+ GR8701iW regular boiler user instructions, 6721890764 (2024/06), Worcester Bosch read 3 November 2026.