Angle valve plastic thread rotates hollow

Hello, a question for specialists. I cannot unscrew my hot water angle valve in the bathroom to replace it – it turns hollow at one point. It seems the plastic thread is damaged. I have already asked at the sanitary specialist shop, with a picture of my wall installation, but they just shrugged, saying it is probably not a standard installation. The plastic holder seems to be the problem. Can someone explain to me what is behind the plastic holder? The annoying thing is, I think that since I tried to turn it here 4 weeks ago, the hot water pressure in the entire apartment (8-family house) has not been as strong anymore. The main water valve is fully open. So far, there is no moisture detected and neighbors downstairs have not complained yet.

Thanks for the tips and advice.

Rental or ownership.

In case of rental apartment, inform the landlord who should send someone. In case of ownership, call someone yourself.

Water damage can be expensive.

Morning

You have loosened the connection hose of the fitting and then tried to turn the valve out of the wall? Although you turned counterclockwise, the valve did not come loose?

As a plumber, I would have now turned off the water and immediately looked for the cause. Possibly something is already broken in the wall.

In your place, to avoid extensive damage, I would IMMEDIATELY order a professional first thing tomorrow morning.

Olli

Hello,

I am the owner. I turned off the main valve in the bathroom, loosened the fitting hoses, and turned the angle valve to the left. It seemed as if it was screwing out slightly, but after about 10 turns in total, nothing more happened. I then stopped to avoid damaging the thread further, in case that is the cause.
I am simply interested in why the requested professional, certainly with over 15 years of experience, we share the same yard at the company, didn’t know what kind of installation this is. Is it something exotic? And what is behind the plastic holder? Is it a coupling that connects the water pipe to the valve? An extension? And could something have happened inside by turning the valve? I did not have to apply excessive force.

Thank you for the effort