Underfloor heating - heating circuit remains too cold.

Hello everyone,

I came across this forum while looking for explanations/instructions about my underfloor heating and hope to get some help. My landlord does not respond and the issue is getting increasingly frustrating.

The situation is as follows.

Underfloor heating throughout an entire semi-detached house. The semi-detached house is connected to a large system where other apartments and houses are also connected. In our semi-detached house, there are three (basement, ground floor, upper floor) such distribution boxes. Basically, everything works as it should, except for a guest room in the basement. This room takes an extremely long time to get warm. Four days ago, we set the temperature to 22 degrees because guests are coming. After two days, the room was at 20 degrees, but unfortunately it has not gotten warmer than 20.6 degrees even after another two days.

After I turned up the other heating circuits in the basement, the temperature in the guest room even dropped again. I assume this is because the cold water from the other rooms is also cooling down the water in the guest room.

My questions to you are:
What setting options do I have?
Where can I, for example, adjust the flow rate?
What could be the reason that the room temperature is not reached?

Thank you in advance

Hi,
What flow rate do you have? I can't read it from the photo. Can you increase the flow rate?
What return temperature does the respective heating circuit have, and what do the other heating circuits have?
For which room temperature was the underfloor heating in this room designed?
Regards

After I turned on the additional heating circuits in the basement, the temperature in the guest room even dropped again. I assume that this is because the cold water from the other rooms also cools the water in the guest room back down.

I would spontaneously guess that either - the supply lines are undersized - the heating pump is undersized and can no longer handle the basement additionally - different temperatures were assumed for the basement rooms in the heating load calculation (always planned as living space or only set up by you like that?) In all these cases, as a tenant, you can do little. However, the fact that the temperature drops as soon as you include other basement rooms does suggest that the flow rate for the entire basement is not right. I also have one more point... what are the other basement rooms and what partition walls do you have there? A warm room next to unheated rooms loses a lot of heat through the walls. In that case, of course, the calculated heating load is no longer correct either.

Is the actuator for Keller 1 intentionally misplaced? In my system, when the actuator is removed, the flow rate is initially 0.

In my system, when the actuator is removed, the flow is open.