ᐅ 3 underfloor heating circuits in the bathroom, 1 not working, what should I do?

Hello everyone,

We have now been living in our new house for a week. Our main bathroom is equipped with underfloor heating consisting of 3 heating loops. The spacing of the heating pipes is 5cm (2 inches). Unfortunately, I noticed that one of the heating loops is not warming up, and it happens to be the one under the toilet :-(

What I have tried so far is setting all 3 loops on the manifold to the maximum flow rate, currently at 4 liters per minute (1 gallon per minute). The ERR function is deactivated. The room temperature setting on the heating system itself (heat pump) is set to 22°C (72°F).

What can be observed is that the floor areas with the other 2 heating loops are warming up, but the tiles above the 3rd heating loop remain completely cold. The building handover has already taken place, but the heating system was accepted on the condition that the heating itself works properly, while the heat distribution still needs to be assessed.

Does anyone have any ideas on what else I could try? I assume I can rule out a kinked pipe in the heating loop if I see visible flow on the related flow meter, right?

Thanks in advance,

Best regards

Here is a picture showing the heating loop at the very top of the image:

Clarification question: Do you really mean a "flowmeter," that is, a display/visibility of an actual flow (in the sense of water moving in one direction)? Or a display that shows the degree of valve opening based on a static water column?

Good question, these are just the standard meters in the heating circuit distributor. Since you ask that way, I think it is the water column of the valve opening.

In this case, a blockage in the pipe behind the valve is still possible – a water column remains. Of course, there would be no real flow, hence the question.

That would, of course, be the absolute worst-case scenario.