Asking for opinion about flow meter concerto

[sirmook]

I'm the homeowner of a heat pump + UFH installation, 2 floors with 1 manifold on each floor and a common pump. On both floors each circuit has the same problem: whenever a zone asks for heat and the motorized valve opens there is a some loud knocking going on (see video). In the case of the video attached pump has already started up and the blending valve didn't move either, so the only change was the motorized valve opening on the top.


According to the installer this is just air being trapped and its normal for new installations and the problem will solve itself (there are ARV's installed on the manifold). I'm still a bit nervous about it because the installation is more than a year old now. My question would be: do you think the installer is right and I should just wait, or there might be something to be done?

Another thing: looks like the flow meters are always in the 0 position even when the zone valves are open and heating is working OK. I thought they should indicate some flow normally. Is this an issue?

 

[sirmook]

UPDATE: the manifold seems to be installed the wrong way around: the return is connected to the flow side and vice versa. Do you think I can just swap the flow meters and the TRV's or its not enough?

 

[Last Plumber]

I would ask the installer to correct it.

 

[exedon2]

Needs flow to be correct through blender valve get it changed.

 

[sirmook]

UPDATE again: I told the installer about how the manifold's flow side is on the return side pipe and vice versa. He said that he used to install it in reverse sometimes but it still works the same and it should not matter since the flow meter is bidirectional and the real problem is air trapped in the system. Since I read a lot on this forum (and from other sources) I knew that he is factually incorrect so I respectfully asked him to leave. I took some time from the weekend to swap the valves and the flow meters and then bleed the system. Now it works well and silent + there is a flow reading for each circuit. This is a win in my book but now it looks like I'll have to learn to care for my system.