dumb question about buderus hydronic panel radiator, green knob does what?

EternalNoob

I installed a model 22 radiator for the first time recently. The rest of the house is staple-up pex (what i'm used to) but super thick sub-floor in two rooms necessitated radiators. They're sharing a single zone and tstat, and I didn't think thermostatic valves would be necessary. I just put them in parallel on a shared home-run loop back to the manifold. I think i left the valves all the way open and expect roughly equal flow through each. They seem to be performing just fine, in fact i'm pretty impressed with the output.

I'm just wondering what the green knob setting does, if anything. There's a yellow protective cap over a green plastic nob at the location where a thermostatic valve would go. My understanding is that with a thermostatic valve would put pressure on the pin to adjust flow, and that with no valve in place, the pin fully extended, the valve is all the way open. The green plastic knob spins freely, has numbers 1 - 7 and then the letter N, and the numbers don't line up with any marks on the valve body.

The radiators came with a multi-page IKEA-style instruction sheet on how to screw the mounting brackets to the wall (like i couldn't have figured that out) but no info about the ports. Online i found info on getting the supply and return ports right and how to bleed the air, but all the how to's i've seen include installing thermostatic valves and don't mention the green dial.

Tom_133

https://s3.amazonaws.com/s3.supplyhouse.com/product_files/Buderus-3-42024-User-Guide.pdf

If you look at that guide on page 10 it tells you what that flow setter does. It allows you to adjust the flow for each radiator. If you replaced the yellow cap with a thermostatic valve it would do it for you. You would set the amount of flow with the green knob and the thermostatic valve would open and close based on temp.

EternalNoob

Thanks Tom, I guess i just didn't see that notch before. All makes sense.