Floor Heating Issue - Single Circuit Not Working Properly Since November 2012

Hello
I have a problem with one circuit of the floor heating.
All floor heating circuits have been working flawlessly since November 2012. Except for one short one that causes a problem from the beginning. One small room is poorly or does not heat up at all.
By adjusting the flow meter (rotamer) in the distributor cabinet on the upper bar, I cannot set the flow value higher than 1. On the remaining loops (and there are 7 of them) there is no problem with regulation. On the second return strip on the defective loop (and the others) there is only a white protective cap and under it the valve stem (like from a radiator without a thermo head). When I press the spindle, in this problematic circuit the level suddenly drops to 0, so it closes. I mean, the valve under the cap is working. Valve movement is the same as on other valves. In the remaining loops the same happens, only that in the flows (rotamers) I can set the flow values from 0 to 4.

Now questions.
1. Is the problem with the air in this malfunctioning circuit? Only after such a time air in the air? And this despite the fact that the rotamer reacts by closing the flow on the lower blade?
2. Is the problem with the top bar in the valve where the flow control + rotamer is?
I bet on problem number 2.
Maybe someone from the Forum members will tell you because the installer has not been able to get the installer for 4 weeks for repair and diagnosis of the defect and winter is coming and the spouse is pregnant.

It is difficult to guess at a distance, the air in it is rather absent. You need to check the input and output of the loop, if it is not clogged, the cable is probably broken or pinched by something. You can try to blow with air pressure, if that does not help, the installation is broken.

The problem lies in the regulation of the floor heating. The flows are set on the rotameters depending on the flow resistance and the heating power of the loop. Tighten the remaining loops gradually until the flows are even or the circuit starts to heat up.

ziomekorko wrote:

The problem lies in the regulation of the floor heating. The flows are set on the rotameters depending on the flow resistance and the heating power of the loop. Tighten the remaining loops gradually until the flows are even or the circuit starts to heat up.

Adjustment on rotamers causes a decrease in flow in loops that are working properly but does not increase flow in a loop that has a heating problem.

Added after 2 [minutes]:

Adamonter wrote:

It is difficult to guess at a distance, the air in it is rather absent. You need to check the input and output of the loop, if it is not clogged, the cable is probably broken or pinched by something. You can try to blow with air pressure, if that does not help, the installation is broken.

I hope that your version with forging falls off because I have poured polyurethane resin on the floors and I do not see the possibility of mechanical interference with the floor.

Yes, I thought that the surface was ready, so I listed the forging as the last one, because I don't see any other possibilities, unless you catch a young mole somewhere, then maybe he can handle it.

Adamonter wrote:

Yes, I thought that the surface was ready, so I listed forging as the last one, because I don't see any other possibilities, unless you catch a young mole somewhere, then maybe he can handle it.

Crete is rather in the spring because now it is probably the best with full bellies.

I think that if he asked him nicely, he would agree to do this task overtime. After all, they are very nice and hardworking animals.

Detach this loop from the manifold and flush the water under mains pressure.
It is difficult to remove air from the floor in other ways.
If there is air in it over a longer distance, it looks like a long eye of the spirit level, which takes up a large part of the pipe cross-section, and only a thin stream of water squeezes under this air hole. in most cases, the floor pump is not able to push such an air lock.

Close all other circuits and try to vent. If only the pump does not work, do as Saskia advises and connect the water hose to the manifold. Maybe give me a photo, we will be sure that this is not some hack on the manifold. For example, a loop connected to the bypass valves.

I closed all circuits for over an hour and left only the shabby one. Unfortunately, the level of the float in the rotameter is at the same level.
But there is some success.
The installation is under warranty so we managed to download the installer / contractor on Monday (I think). He suspects the valve under the rotameter because he has already had two such cases. Well, unless it does not show up, I undress myself. I will inform you about the progress.

Problem solved. On the lower strip of the distributor prod. The gorgiel upper part of the valve (the movable one with a rubber mushroom head) was something slightly clunky. After replacing the top part only, the problem was solved. The upper strip of the distributor, where the rotameters are, was ok. Thank you for all your help and advice.

At the end, such a small digression.
I am worried that the installer = the contractor took 50 PLN for the repair. And he bought the equipment on an invoice for himself, the installation is one year old and the problem occurred in March this year. I got an invoice for the installation with 8% VAT. But somehow he did not care and did not take it on his chest that the equipment was faulty from the beginning. He already did one trip to unscrew the twisted rotameters and he also deleted 50 PLN. Eh ... C'est la vie

I believe that this cash flow should probably be in the opposite direction because of the shortcomings and the hassle associated with it. I am also an installer and I would be ashamed to do so. I also had minor faults which I removed immediately, and the clients offered me at least a refund for my journey, but I always refused and I feel good about that. And I have had regular clients for over 20 years, and my clients also ask me to entrust them with colleagues for works that I do not do, and this is better than the PLN 50 stripped from the client. [/ center]

Adamonter wrote:

I think that this cash flow should probably be in the opposite direction because of the shortcomings and the troubles associated with it .... [/ center]

I share your opinion. Unfortunately, my installer is not so much. I consider the topic to be resolved. Thanks to everyone for the tips and tricks.