Radiator Heats Only Halfway: Top Warm, Bottom Cold - Thermostat & Return Pipe Solutions

ok, I'll start with this filter, aha I will add that the inlet and outlet valves are working and are very hot, the inflow may be slightly more than the outflow. Tesciu tells me that maybe the underfloor heating takes so much heat that there is not enough heat for radiators and it is all on the same pump. but then why does some radiators heat well and others less? I exclude the reverse connection option because a year ago they all worked well and nothing was changed.
Maybe it is because the water was not drained from the entire circuit after the end of the previous season and somehow the radiators inside these radiators rusted, which may indicate that the water was very rusty when venting.

Maybe it is because the water was not drained from the entire circuit after the end of the previous season and somehow the radiators inside these radiators rusted, which may indicate that the water was very rusty when venting. [/ Quote]

Hello!
We never drain the water from the installation after the end of the season.

qusha. explain to me is there any rule that some heaters heat less well and others do well? e.g. on storeys? that is, the ground floor is ok, the first floor is not. or other addictions? or chaotic? Flooring shouldn't matter here
meaning.

I noticed that it depends on the riser, for example, in one riser there are 2 radiators in the room on the ground floor and directly above it, which heat up brilliantly, while on other risers they are underheated. In addition, I checked that at -23 degrees, I turned off the three heaters completely, after a few hours when it was freezing in the room, I turned them on again, the heaters reached their maximum temperature in less than 10 minutes. Only one fully and some half of the area.
I turned off the underfloor heating and still the same. The plumber said you need to heat min. 60 degrees on the boiler for a week to make it equilibrate because the circulation is too large. The filter I have only oblique no additional, just cleans it.

qusha. I don't know yet what your connection to the radiators is. side or bottom? in any case, it will be good if you adjust the flow on the valves on the return. when they are tight, close the inflow and always unscrew them in each case equally by three turns. it's back. power supply, while at the side you will probably have a valve with the head. so unscrew the heads on each one and check on the valve how the numbers match. check if there is any relationship between these settings with underheating of the radiators. To sum up: the rule of thumb is to set the same flow on the return. power supply to max (i.e. when you remove the heads, the needle will unblock the flow), write what and how. do not touch the flooring. let it warm normally. not much influence here.

Added after 1 [minutes]:

only as a rule, set the flow knobs equally

As I mentioned at the beginning, I have the bottom power supply on the right. When I turn this screw at the bottom, it does not come out or screw in, just when it is in the "I" position, it is full flow, and when "-" it does not exist. I turned on one heater and then unscrewed the inflow first and then the outlet and nothing changed ...

qusha. well. then you have consoles with ball valves. leave the supply in position "I" (from the inside of the radiator) and the return (on the outside) in the 45-degree slant position. The radiators have screwed valve inserts and the heads are attached. try to take them off and read how the numbers match. the rest, do as I wrote above and let us know what resulted from the observation.
greetings
wish warmth :)

Added after 15 [minutes]:

to unscrew the heads you have to set to max open (5)

The team came and fixed it.
It turned out that such a case also appeared in others, where they installed installations.
They changed it to a closed system, changed the water, added some special fluid to the installation so that it would not rust from the inside and put a few vessels so that the pressure would not burst the installation in case the water in the boiler boiled.
The most likely cause was excessive sedimentation and rusting from the inside because air was supplied to the installation in an open circuit.
I consider the topic closed.

Hello.
I have a gas stove and 1 heater heats up poorly and is cold at the bottom half of the room the tube is supplied and the return is warm all the radiators in the house are warm, except that 1 is vented and it is not the farthest, the pump is on 3

For those who come here because they are looking for why the radiators heat poorly.
I have steel plate radiators.
These radiators are not painted from the inside and simply rust, but if you prefer steel, they oxidize in a peculiar way: there is such a black sludge that settles at the bottom of the radiators. And petrified black lobes circulate in the installation.
Rinse the radiator with the system full and pressure almost 2 bar by unscrewing the bottom plug in the radiator.
You can also drive a magnet over the radiator from the bottom up because the deposits are iron.
Ideally, use a Fernox F3 cleaner followed by an F1 inhibitor to help stop corrosion.
The procedures are described on the manufacturer's website. I used the Silver method.
Two out of 19 radiators were stained after 5 years of use.
I also changed the three-way valve insert because the black stone also settled on the axle.

I have the same problem, do you think that changing the hydraulic settings at the valves will help? 2 new purmo heaters bought and put on a few days ago and one heats up poorly and only half, I pulled up the stove to high temperature and the pump also for 3 and nothing special, on another forum they advised to change these settings, but what do they actually give to what is it and what principle it works.

Hello The problem turned out to be the thermoregulator that had too little capacity, the solution was the butterfly valve (by the radiator) which did the trick and now the radiator flashes like this la la I consider the topic closed