Hovering around 20 minutes error a night at the moment (though it doesn’t run every night, depending on water usage)
However a couple of times when I have been using more HW than normal I have rrequested more, evther via the “boost” option or by changing to manual mode. Both times nothing happened….until I reset the Vailant controller in the cupbard at which point the app started to respond. Not sure what could cause that….
It looks like you don’t have an AAV on the DHW coil, it appears you’ve only got a manual air release on the DHW coil:
I think you might be right, however the big black block just after the flow meter is a de-aerator fitted a few weeks ago by heatGeek?
I have checked that manyal vent though, and no obvious sign of air
I’ll keep an eye on it over the next few months.
CH always fine. DHW hat 53 minutes in flow meter error last night.
I wonder if perhaps this particular flow meter is more susceptible to errors than A.Nother brand….
Hi Ben. Here’s my system installed 12 months ago. See how long it took for the air errors to clear - and I was actively trying to clear the problem every day. Like you I had a de-aerator fitted shortly after install.
But now, I’m not getting errors any more - even through this summer when the only use of the pump was DHW runs every day.
It’s a relief and a joy when the errors stop 
