Operating status
Worcester Bosch Boiler 204 — Operating Status
The actual boiler water temperature is above its target, and the boiler is switched off in this operating state. Confirmed for the Greenstar 8000+ and 8000+ Style models covered by manual 6721891026 (2024/06), not every Worcester boiler. Record any accompanying letters or subcodes.
Quick answer
204: Boiler water above the target temperature
Meaning
Boiler water above the target temperature
First safe check
Record the full display and confirm the exact boiler model.
Seek advice if
Heating or hot water is unavailable when expected, another fault appears, or a service mode is active unexpectedly.
Who to call
Contact Worcester or a Gas Safe registered engineer if the boiler is not providing the expected heating or hot water, another warning appears, or a service mode is active unexpectedly.
This is an operating message on the documented models; the code alone does not establish a breakdown. Match the complete display and appliance model before interpreting an operating status.
What does this status mean?
The actual boiler water temperature is above its target, and the boiler is switched off in this operating state.
The manual classifies this as an operating/status message, not a component-failure diagnosis.
Confirmed for the Greenstar 8000+ and 8000+ Style models covered by manual 6721891026 (2024/06), not every Worcester boiler. Record any accompanying letters or subcodes.
Why is this happening?
- The actual boiler water temperature is above its target, and the boiler is switched off in this operating state.
What to check
- Record the full display and confirm the exact boiler model.
- Check the operating-code entry in the matching user manual; this status alone does not call for a repair or reset.
- If heating or hot water is unavailable when expected, note the controls and any other messages and ask Worcester or your engineer for advice.
Does this status need a repair?
Not indicated by this status aloneNo repair is indicated by this status alone on the documented model.
Safety boundary: Do not remove the boiler casing or work on gas, combustion, flue components or internal wiring.
What not to do
- Do not remove the boiler casing or work on gas, combustion, flue components or internal wiring.
- Do not order parts or repeatedly reset the boiler solely because this operating number is displayed.
Common misdiagnoses
- The manual classifies this as an operating/status message, not a component-failure diagnosis.
When to call a heating professional
Contact Worcester or a Gas Safe registered engineer if the boiler is not providing the expected heating or hot water, another warning appears, or a service mode is active unexpectedly.
Safety warning
Do not remove the boiler casing or work on gas, combustion, flue components or internal wiring.
Useful hub links
Other Worcester Bosch boiler codes
Worcester Bosch Boiler 201 — Operating Status
Hot-water mode
Worcester Bosch Boiler 202 — Operating Status
Anti-cycle mode
Worcester Bosch Boiler 101 — Code Meaning
Collector T1 sensor lead short circuit with controller Fault 40
Worcester Bosch Boiler 102 — Code Meaning
Collector T1 sensor lead break with controller Fault 40
Relevant guide
Frequently asked questions
Does 204 prove that a part needs replacement?+
No. The cited manual records an operating status. A separate symptom or fault needs its own assessment.
Does this definition apply to every model?+
Confirmed for the Greenstar 8000+ and 8000+ Style models covered by manual 6721891026 (2024/06), not every Worcester boiler. Record any accompanying letters or subcodes.
Sources and review status
Model dependent · Last reviewed 21 September 2026
- Worcester Greenstar 8000+ / 8000+ Style manual 6721891026, pages 74–76
model manual · UK · checked 21 September 2026
The code definition and stated model/region scope. The manual classifies this as an operating/status message, not a component-failure diagnosis.