Discuss WB Greenstar 4000 Combi Fault Code 2965 in the Central Heating Forum area at PlumbersForums.net

John.g

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What is the boiler flow temperature required to flag this 2965 fault code?.

This, I believe, is a blocking code that trips the burner but when/if it resets. the burner will refire without any boiler reset?

If this fault code is up while in CH mode and there is a demand for HW, will the boiler still change over to DHW mode (combi) and refire the burner once this fault code clears.?

If the boiler is in DHW mode and this code is flagged does the burner just trip and then refire each time it clears?
 
Hi John

Did you fix your error with your boiler? What was causing the problem in the end?
 
I don't have this boiler but this problem has cropped up from time to time, apparently this fault code 2965 is flagged if the heat exchanger temperature exceeds 88C (WB inform), this seems a very low setting to me as the boiler CH flowtemp can be set as high as 82C, if the heat demand then is lower than the boiler minimum output the burner will trip (like all gas fired boilers) when the flow temperature exceeds target temp+5C, in this case, (82+5), 87C, and then refire once the anticycle time has elapsed and the flowtemp is targettemp-5C, it seems a bit illogical to have such a low setting of 88C (for code 2965) in view of this? even though most will rarely if ever run with flow temperatures as high as 82C. I think I read somewhere else that this setting is actually higher than 88C (despite what WB inform), I will try and poke around and find this.
 
I think it is more likely that this setting is/should be at least 98C since the burner trip temperature is settable between targettemp +2C and +15C, default +6C.
1714906255977.png
 
WB inform (again) that this (2965) is set to 88C, monitored with a sensor on the heat exchanger which presumably closely reflects the flow temperature.

So it would seem to be normal for this blocking to occur (if minimum boiler output greater than the minimum heating heating demand) if one wanted to (even though unlikely) run with the max flow temp of 82C with the default anticycle temp off of +6C or if running with a modest 73C flow temp and a anticycle temp off set to 15C

1715324385572.png
 

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