Central heating closed system losing pressure daily, no visible leaks, radiator overflowing

Hello,
I have a problem with constant pressure drops in the central heating installation. Closed system, the pressure can drop practically to zero every day. You can not see any leaks anywhere, everything is capped. One of the radiators is constantly overflowing, and you can hear the same sound in the boiler. one phenomenon in the morning when the pressure drops to almost zero and I am going to bleed the radiators, the pressure starts to increase to about 0.4. For any advice I will be grateful
dreams

marzena5 wrote:

Another phenomenon occurs in the morning when the pressure drops to almost zero and I am going to bleed the radiators

But why do you bleed the radiators?

marzena5 wrote:

the pressure begins to rise to around 0.4.

Itself? -no, you are doing something?

Lack of air in the expansion vessel is very likely the cause of problems.

If you feel up to it, you can try it yourself.
It seems to me, however, that the service technician's boiler has not been seen for a long time and the inspection would not be harmful.

To stanislaw1954
Shouldn't I be venting?

The pressure starts to build up as you bleed the radiators (should it be?).

marzena5 wrote:

Shouldn't I be venting?

The radiators are vented when the installation is filled, or when one does not want to heat - then this particular one is enough.
In this case pirate he will be right - no air in the expansion vessel.

Since there is no air in the vessel, I have one more question: I know that I can pump up the air with an ordinary pump, but can I do it without removing the vessel from the installation?

marzena5 wrote:

can I do it without removing the vessel from the installation?

Of course.

marzena5 wrote:

can I do it without removing the vessel from the installation?

Yes. Before that, you need to close all the valves under the boiler and drain the water from it.
Inflate to about 0.8 bar and drain the water from the boiler again.
Re-pump to 0.8 bar and drain the water until you reach a situation where the vessel is about 0.8 bar and the water from the boiler no longer flows.

If the pirate was right, there should be a pool of water under the boiler every morning, which is thrown out by the safety valve, because the damaged vessel does not compensate for the pressure increase in the installation. If this is not the case, the vessel must be checked, but the cause may lie elsewhere.

More and more boilers drain to the sewage system from the safety valve. So the puddle is not that obvious.
It is often a really small amount of water which is sometimes difficult to see under the boiler.
It also happens that the boiler is built in such a way that it will come out somewhere only when the valve is sent by a bucket of water.

It does not mean that it is 100% fault of the vessel. However, it is the most likely cause of the fault.

Tomorrow I will try to pump up the expansion vessel. Please tell me what to do when I get up in the morning and the pressure drops completely? First, pump up the vessel, then add water and bleed the radiators.

Nevertheless, since there is no air cushion in the vessel, i.e. the vessel is full of water, this water must run away somewhere, especially as you have to tap it every day.

There is no point in getting a doctorate, we will wait for my friend Marzena5 to check the vessel and then we will consider what to do next.

I saw an installation where, in a thread led through the wall, I would like to add that the installation made of copper, one of the elbows, looked like Swiss cheese. It's just that the copper at that point has been scavenged, and that is where the leak was. The defect is invisible at a glance and very difficult to detect.

Added after 14 [minutes]:

Order like you say:
- replenish the pressure in the vessel,
- let water in
- bleed if necessary.

I have a question, what is the boiler and what is the pressure in the installation?

Viessman mono boiler with 33kw power, solid fuel. I try to keep the pressure on the stove 0.8 bar. The installation is new 4 years ago, but it's the first year of burning in what.

marzena5 wrote:

Another phenomenon occurs in the morning when the pressure drops to almost zero and I am going to bleed the radiators, the pressure starts to increase to about 0.4.

Maybe during this venting process, you just inflate the air and the pressure rises from the height of the water column.

The heaters are deaerated if the pressure in the boiler is correct. Otherwise, the effect will be counterproductive.

How high is the installation. What is the difference in height between the boiler and the radiator at the highest point.
e.g. a boiler in the basement, and the highest heater on the first floor is about 8m of water column, so if you have it, the pressure you set is definitely too low.

The house is a one-story house with a usable attic, the church on the ground floor, the highest heater is a bathroom in the attic about 4 m above the boiler.

marzena5 wrote:

about 4 m above the boiler.

Hence increasing pressure up to 0.4 bar.

Check this vessel and let me know what and how.

piracik wrote:

marzena5 wrote:

can I do it without removing the vessel from the installation?

Yes. Before that, you need to close all the valves under the boiler and drain the water from it.
Inflate to about 0.8 bar and drain the water from the boiler again.
Re-pump to 0.8 bar and drain the water until you reach a situation where the vessel is about 0.8 bar and the water from the boiler no longer flows.

And it is not easier to just leave the valves open and pump until the vessel is 0.8 bar and the water stops flowing from the boiler?

A closed circuit and a solid fuel boiler are not the best combination. Under what circumstances did the problem arise? Was it not that, for example, there was no electricity, and the boiler was hot?

mauri_b wrote:

And not easier to just leave the valves open and pump until the vessel is 0.8 bar

Easier. Provided that the water does not have to be caught and it does not pour somewhere behind the cabinets.

I would like to tell everyone that I will not start pumping up the air until Saturday, (work). As you suggest, it will punch the diaphragm vessel to 0.8 bar. After pressing the valve, air comes out of the vessel, not water, I understand that the membrane is not leaky. To what pressure should I add water to the stove? Also to 0.8?
What could be the reason why the water in the boiler keeps overflowing (with pumps running)?
To legal
no, there was no electricity,

One more question: when venting pumps, how much water should the water flow after unscrewing the screw?

What if it is a leak in the floor or flooring? View from a thermal imaging camera? Have any of you found leaks this way?

Oh, this morning the pressure dropped to 0.1, what do you advise to let in water or not and start smoking with this pressure?

For leaks that are not visible, a liquid should be used to seal the installation.
Does the boiler have a cooling device? If not, open the system, just for your own safety
Each "overflow" of water in the installation indicates that there is air in it.

The stove has a cooling device, today I spoke on the phone with the man who installs the heating installation, he told me to cut off the floor completely, add water to 1 bar, and see if it would fall by the morning.

The floor is the least suspect. Unless someone has drilled.