Hello
I have a new ecoTEC 612 that, from the outset. made a very loud rumbling noise, at random, every day but only when power was modulated down for low heat demand.
Of course it would not do it when my plumber came back to fix it so Vaillant were called.
The Vaillant engineer knew from my description exactly what the problem was even before he looked at the boiler, and increased the minimum fan speed via D.051 to stop the flame lift that causes the noise. Only took a few moments and now have nice quiet boiler.
Hope this helps someone else as I see it happens to others posting here.
I have a new ecoTEC 612 that, from the outset. made a very loud rumbling noise, at random, every day but only when power was modulated down for low heat demand.
Of course it would not do it when my plumber came back to fix it so Vaillant were called.
The Vaillant engineer knew from my description exactly what the problem was even before he looked at the boiler, and increased the minimum fan speed via D.051 to stop the flame lift that causes the noise. Only took a few moments and now have nice quiet boiler.
Hope this helps someone else as I see it happens to others posting here.
