Vaillant EcoTec Plus 612 - Troubleshooting Error V.61, Suggestions & Help Needed

kch70 wrote:

Thank you for the information.
Is a symptom of a motherboard failure can also be large pressure peaks between the furnace rest and its operation. (during standby 1.2 bar, heating of water in the tank 1.6, and heating operation up to 2.4).

boodles wrote:

Hi,
did you replace the motherboard in the oven yourself? If so, where did you buy? And how much did it cost you?
I am asking because I have such a problem.

greetings
B.Art

Qdlaty78 wrote:

I stick to the topic with observation. Error f.61, while maintaining the correct operation of the gas unit (after resetting the stove, it works for several or several dozen hours) is the fault of the capacitors. I had just such symptoms (Ecotec plus VC186 / 3-5). It works fine, fun and everything, until suddenly (often synchronously with the switching of the multi-way valve) the flame goes out and the error f.61 is triggered. The band coil had the correct resistance (330 Ohm as I remember correctly). I measured the voltage on the coil during operation - it should be 22V and it was 17V. This caused the valve to open, but any increase in current draw from the 24V power supply on the board or other destabilization, e.g. voltage fluctuations in the mains, closed the valve. I replaced 2 capacitors (470uF / 35V / 105C, I bought identical Epcos by luck).
Looks like it helped. The stove is working properly, the tensions are correct, the family is happy.

ps This is definitely a repair for someone who has an understanding of electronics and the operation of the furnace itself. Prudence and attention are required. The coil may have the correct resistance, but e.g. the valve may have a mechanical failure. The controller will report the same error, because it checks whether the flame ignites after opening the valve and giving a spark (based on the ionization of the igniting electrode). Fumbling with the gas valve itself is absolutely unacceptable, as are attempts to repair when an additional F.62 appears, which means too high ionization current. As long as it is due to dirt on the electrode, it is a small matter to be cleaned. However, the same error may mean that the gas valve does not close, which may result in gas leakage and explosion.
pps but I don't know myself, I'm not a vaillant service technician