Worcester Bosch fault code 2967 means the boiler has detected an excessive temperature difference between its flow or supply temperature sensor and the temperature sensor at the heat exchanger.
The manufacturer wording varies slightly by model. Current Greenstar 4000 documentation says: “The temperature difference between supply temperature sensor and temperature sensor at heat exchanger is too large.” Greenstar 1000 documentation describes the same condition more briefly as “Flow/heat exchanger temperature sensor differential too great.”
In plain English, two temperature readings that should follow a sensible relationship are too far apart. That can happen when heated water is not moving through the boiler as expected, when the system contains air or lacks adequate pressure, or when a temperature sensor, its contact or its electrical connection is not reporting correctly.
The code does not identify one failed part by itself, and it is not universal across every Worcester Bosch range. Confirm the exact boiler model before applying any fault-code meaning.
What does Worcester Bosch 2967 mean?
A boiler monitors temperatures at key points to control heat safely. On the applicable Greenstar models, one sensor measures the heating-water supply or flow temperature and another monitors temperature at the heat exchanger.
If the difference between those readings becomes too large, the boiler displays 2967. Worcester Bosch places it in fault category B in the manuals checked for this article.
The difference may reflect a genuine flow problem, where heat is building in one part of the boiler faster than it is being carried into the heating system. It may also arise when one of the temperature readings is inaccurate.
That is why code 2967 should be treated as a starting point for professional checks, not as proof that the pump, a sensor or any other single component must be replaced.
Which Worcester Bosch boilers use code 2967?
The code is documented for the Greenstar 4000 and Greenstar 1000 models covered by the current manufacturer literature used here. Worcester Bosch has produced many boiler ranges with different electronics and code lists, so an identical number should never be assumed to mean the same thing on every appliance.
Look for the full model name on the boiler’s front or an accessible label. Photograph both the model and the displayed code for the attending engineer.
If your boiler is not one of the documented ranges, use the model-specific Worcester Bosch manual rather than relying on a generic fault-code list.
What can cause a large temperature difference?
Worcester Bosch’s technical checks for 2967 cover several areas. Translated into homeowner-friendly terms, possible categories include:
- insufficient water flow through the boiler and heating system;
- low system pressure or a system that is not adequately filled;
- air trapped in the heating circuit;
- closed or restricted circulation routes;
- a circulation-pump problem;
- poor contact between a temperature sensor and the surface it measures;
- a faulty temperature sensor;
- a wiring or connection fault.
These are possibilities, not a remote verdict. Some involve components inside the sealed boiler casing and require suitable instruments and competence. Do not remove the cover, test wiring, measure sensor resistance or work on the pump.
What might you notice with code 2967?
The boiler may stop or limit heating to protect itself. You might also notice radiators heating unevenly, unusual changes in heating performance, or the fault returning after a reset.
However, symptoms vary. A house with code 2967 can have cold radiators, partly warm radiators or no obvious circulation symptom before the boiler stops. The display and exact model are more reliable evidence than trying to identify a failed part from the feel of one radiator.
For a broader look at circulation symptoms outside the boiler, see why some radiators stay cold.
Safe checks you can make
Keep your checks external and observational:
- Photograph the 2967 code before it changes.
- Record the full boiler model.
- Note the visible pressure reading while the heating is cool.
- Check whether several radiators are cold, partly warm or heating normally.
- Look for an obvious external water leak around radiators, valves and accessible pipework.
- Note whether radiators were recently bled or heating work was carried out.
- Record any other code that appears before or after 2967.
Do not open the boiler casing, touch internal pipework, test sensors or wiring, or attempt to free a pump. Do not enter installer menus or repeatedly reset the appliance.
If a radiator or exposed pipe is very hot, do not keep touching it. If water is near electrical equipment, keep clear and seek prompt professional help.
If you smell gas, suspect carbon monoxide or a carbon-monoxide alarm sounds, stop using the appliance, ventilate the property, avoid electrical switches and call the National Gas Emergency Service on 0800 111 999 from a safe place.
Will resetting clear code 2967?
The display may change after a reset, but that does not confirm that circulation and sensor readings have returned to normal. If the underlying temperature difference remains, the code can return.
A single reset performed in accordance with the user instructions may help record whether the fault is persistent, but repeated resetting is not a repair. Never follow online instructions that require an engineer menu, removed casing or internal electrical measurements.
Photograph the code first so the information is not lost if the display changes.
Can low boiler pressure cause 2967?
Low system pressure is one of the conditions the manufacturer’s technical checks consider because it can affect water flow through the appliance. It is not the only possible reason.
If the visible pressure is low, record the reading. Avoid repeatedly adding water, particularly if pressure has been falling over time. Ongoing pressure loss can have its own cause and should not be hidden by repeated refilling.
Our boiler pressure guide explains normal pressure behaviour in plain English.
Can I keep using the boiler?
Do not try to force the appliance to operate if it has stopped with code 2967. The boiler is reacting to a temperature relationship outside its expected range.
If the fault clears but returns, arrange a repair. Continuing to reset the boiler does not address restricted flow, inaccurate sensing or an electrical connection problem.
A Gas Safe registered engineer can verify the code against the exact model and carry out the internal checks safely. Depending on the evidence, that may include system flow, pressure, air, pump operation, sensor contact, sensor readings and wiring continuity.
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Worcester Bosch 2967: quick answers
What does Worcester Bosch fault code 2967 mean?
It means the temperature difference between the flow or supply sensor and the heat-exchanger sensor is too large on an applicable Worcester Bosch boiler.
What can cause code 2967?
The code can be associated with restricted water flow, low pressure, trapped air, circulation problems or inaccurate temperature information. The display alone cannot identify which condition applies.
Can I reset Worcester Bosch 2967?
Use one normal reset only if the exact model’s user guide permits it. If 2967 remains or returns, keep the boiler closed and book a professional repair.