ᐅ The Vaillant VCW 196EC is experiencing intermittent operation issues.
Created on: 28 Nov 2025 10:46
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Curiosius
Good morning,
a Vaillant Vcw 196EC heating system frequently stops working intermittently. It runs normally, and then, without any changes to the settings on the unit or the radiator thermostat, it displays the error E12. Sometimes also F40 or F23. Pressing reset stops the issue for hours. A new expansion tank and several other parts have been continuously replaced. It still needs to last a while... There is enough water in the system. What could this be?
Curiosius
a Vaillant Vcw 196EC heating system frequently stops working intermittently. It runs normally, and then, without any changes to the settings on the unit or the radiator thermostat, it displays the error E12. Sometimes also F40 or F23. Pressing reset stops the issue for hours. A new expansion tank and several other parts have been continuously replaced. It still needs to last a while... There is enough water in the system. What could this be?
Curiosius
C
Curiosius2 Dec 2025 14:44Nauer schrieb:
Yes, the special key ensures precise movement of the valve insert without damaging it. Just a slight turn is enough, only check, do not fully open!Hello, can I show you photos of 2 special keys here, since the forum warned me about links?
Regards, curiosius
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Curiosius2 Dec 2025 19:13Good evening @Nauer
here are the pictures...
curiosius
here are the pictures...
curiosius
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Curiosius4 Dec 2025 07:38Nauer schrieb:
Does any of them fit? Have you tried?No.
That’s why I’m asking in advance.
Is the valve always located on or inside the radiator?