ᐅ Flow rate setting for underfloor heating at the manifold in liters per minute (L/min)

Hello everyone,

I have set a desired temperature of 21.5°C (70.7°F) on my heating system (air-to-water heat pump) at the bottom. The room thermostats are all fully open (set to 33°C (91.4°F)).

So far so good. Almost all rooms reach 21.5°C (70.7°F). Only in the bedroom (upstairs) does it reach a maximum of 20.7°C (69.3°F). Now I wanted to increase the flow rate slightly at the distribution manifold. According to my online research, you only need to turn the red cap on the flow indicator to increase or decrease the flow. This should allow more warm water to reach the room and raise the temperature.

However, below the flow indicator, I found a sticker from the heating installer. The sticker says “Warning! The flow indicator serves only to shut off the heating circuits.” (see the photo)

Does this mean that fine adjustments cannot be made there at all? Where else can the flow rate in liters per minute be adjusted?

Does this mean that fine adjustments cannot be made there at all? Where else can the flow rate in liters per minute be adjusted?

vaderle schrieb:

So far so good. In almost all rooms, 21.5°C (71°F) is reached. Only in the bedroom (upper floor) does it reach a maximum of 20.7°C (69°F).

That’s great!
Why do you want the bedroom warmer than 20°C (68°F)?

vaderle schrieb:

Does this mean that no fine-tuning can be done there? Where else can the flow rate in liters per minute (l/min) be adjusted?

At the return line below the actuators?

Just don’t adjust the valves on the glasses; the flow is set at your manifold where the actuators are attached!

The little glasses didn’t seem completely sealed anyway, judging by the oxidation.

RotorMotor schrieb:

That’s great!
Why do you want the bedroom warmer than 20 degrees?

At the return line below the actuators?

Good question. My basic idea was that, at least in theory, I can set the desired temperature anywhere. Probably, I wouldn’t actually want 21.5°C (70.7°F) in the bedroom, but rather around 20°C (68°F). Especially since we often sleep with the window slightly open.

Then I would generalize the question a bit and not limit it only to the bedroom topic. Where is the flow rate generally adjusted? I took a better photo of one of the distribution manifolds (this time from the ground floor, but it also has this label).

Can you explain from this where one would need to "turn"?

halmi schrieb:

Do not adjust the valves on the glass parts; in your manifold, the flow is controlled where the actuators are mounted!

The glass components don’t seem to have been completely sealed anyway, judging by the oxidation.

What happens if you turn them? There was a special key hanging in the manifold box that fits those heads exactly. You can see it in the new picture, on the right in the middle.

They break... we also have a Roth manifold.

The key is for the valve located under the actuators (the dark gray parts where the red cap is visible by the flow).