Radiators Warm Only at the Top: Examining Uneven Heating, Regulator Settings, and Gas Boiler

The radiators are vented and when the regulator is set to 5 (maximum), the summer ones are only at the top of the radiator and so about 5 cm lower, and they are cold below. This includes two radiators in two rooms. It is very cold in the rooms. In the bathroom, when the regulator is set to 5, the radiator is warm to the point of burning. And the fourth radiator in the bedroom behaves like the two previous ones, but when set to 3, if I turn the regulator to 5, it does not heat and is cold the same as on 0. What is this about? maybe someone knows...? I would like to add that the apartment is in a multi-family block (150 apartments) with its own gas boiler room. No such problems with the neighbors. The previous two heating seasons were fine for me too. Please help and thank you in advance

And it wasn't that this radiator was not used for longer, or the installation was not recently flushed. Maybe some syphilis from the installation got into the thermostatic valve.

I think that someone from the neighbors removed orifices from the valves, or changed the pre-settings. In that case, you can't help yourself.
Regards, Grzegorz

Hello, I have a problem as in the title.
More details, I live (rent) in a two-family house, on the ground floor, basement, unheated basement, area, approx. 100m2. The house is about 40 years old, old-date installation, cast iron radiators, thermostatic valves that have not been touched for years. The problem occurs in the two largest rooms (separate circulation) each over 20 m2. There are 25 cast iron ribs in one guest room (length 2 m) entrance up, exit down the same side, the top heats along the entire length and the lower the radiator, the colder, I will add that the neighbors upstairs have a hot house when I smoke and want to have a normal temperature . In a room. What to do, where to start so that the radiator gives more heat over its entire surface. I will add that on the second circuit, where in smaller rooms, kitchens, bathrooms there are smaller radiators, they are hot from top to bottom. Help;

Hello!
You have to go talk to your neighbors and choke their radiators. The heat takes the easier way and goes up, these are the laws of physics.

boskiori wrote:

The previous two heating seasons were fine for me too

Remove the head from the valves and press a few times on the little wire that sticks out of the valve. It should move slightly. Often this pin can "stuck"

12 gucio what does "throttle their radiators" mean, because I don't really understand what this action is supposed to mean?

mirrzo, I suspect that there is no small wire in the thermo valve, as I wrote above, the installation is of an old date and the thermo valve looks like an ordinary valve, either one or the other, although I am not sure

Added after 1 [minutes]:

12 gucio typo of course "choke"

Added after 1 [hours] 48 [minutes]:

12gucio Choke or screw on the thermostatic valve (neighbors) so that the radiator that is higher will consume less and then more hot water will go to the radiator that is on the lower level? does it make good sense?
And below is a picture of my thermostatic valve, if you can call it that

Hello!
You think right, you need to screw it to the maximum at the beginning, when they start to heat you can gently unscrew it. You have a regular old-type valve. They had a throttle setting, maybe they are dirty. You will have some fun but there is light at the end of the tunnel. Good luck and be patient with the adjustment.

mcryb wrote:

And below is a picture of my thermostatic valve, if you can call it that

You can call it what you want, but the thermostatic wheel did not even lie.

This valve is a HISTORIC. During the heating season, it is better not to rotate it, as it may start to leak, especially if it has not been moved for several years and the seal may have aged. However, if you try to turn it and it starts to leak from under the spindle, it means that you need to seal the gland. Then you need to unscrew the visible hood nut, remove the gland (with pliers), wind the tow (linen or hemp) well saturated with thread paste on the spindle axis, push it in, push the gland and tighten it with the hood nut. Orifice for these valves is traditional - changing the flow requires replacing the orifice, which involves the need to drain the water!!! Maybe the orifice is silted and therefore the radiator does not heat, but this also requires draining the water, because you have to at least unscrew the valve head and manipulate the wire to push the orifice. Since the water needs to be drained to change the orifice (or clog the orifice), it is better to simply drain the water and replace the valve with a modern thermostatic one (having a pre-setting, replacing orifice, which can be corrected at any time without draining the system).

Zbigniew Rusek wrote:

Orifice for these valves is traditional - changing the flow requires replacing the orifice, which involves the need to drain the water!!! Maybe the orifice is silted up and therefore the radiator does not heat, but this also requires draining the water, because you have to at least unscrew the valve head and manipulate the wire to push the orifice.

Well, that's not entirely true.

Here are pics of the valve "from the inside".
You loosen the nut with a 30 wrench and a smaller one, probably 22, turn the head left-right to change the setting of the diaphragm to the hole inside the valve.

What mirrzo wrote is also like an additional "crinkling" (normally, a drilled metal disc is given as a ruff - often in the People's Republic of Poland they gave coins, just with the use of such valves). This shutter, when positioned on the side of the radiator, can effectively block the flow of water. So you have to set it from the opposite side. One correction. The nut is unscrewed with a size 27 wrench (preferably ring spanner) if it is a 1/2 inch valve.

bleed these radiators there should be a small valve put a container to it turn this valve when you hear air then wait for water to flow into the container just don't burn yourself

Please correct spelling errors
mod - mirzo

Yes, drilled orifices were inserted, but on the return.
As for the size of the key, it depends on its size - this one was 3/4, so it was size 30, but the sense of adjustment is the same. Often, after adjustment, these valves tended to leak if not tapered. He wasn't, he went to the steelworks.

mirrzo wrote:

Yes, drilled orifices were inserted, but on the return.

I have encountered such drilled orifices just on the power supply, even in the block where I live (before thermostatic valves were installed by a certain company), but not only there.