Optimal Usage of Plate Heat Exchanger in Fireplace with Water Jacket & Open Expansion Vessel

I have a fireplace with a water jacket, an open expansion vessel and a plate heat exchanger. However, the system heats very poorly, i.e. a hot stove and summer heaters. What is the plate heat exchanger used for, is it always necessary? If I have an expansion vessel, could I remove the exchanger?

gurix wrote:

What is the plate heat exchanger used for?

It is used when connecting an open heating system (fireplace) with a closed one (gas boiler). Is the fireplace only as a support or as a main source? Is the circulation pump available? Sketch a diagram. The fireplace through the glass will always be hot. what temperature at the exit from the coat? If the fireplace is a boiler, I don't see the point of using a heat exchanger, two circulation pumps, etc.

And if I would give up the heat exchanger, should the expansion vessel be installed at the highest point, i.e. higher than the highest radiator?

Added after 1 [hours] 30 [minutes]:

I got really pissed off at the weekend, took a hammer and "smashed" the fireplace casing. I studied the forum and here are my conclusions. (I attach a makeshift scheme of my installation and a few photos):
1. The fireplace is not connected to the cross, and in my opinion it should
2. One of the filters (the one on the radiators supply) is mounted upside down.
3. Here I have the biggest problem, namely, the plate heat exchanger, it's not enough that my opinion is too small 12 plates, I'm not sure if it is properly installed. The water circulation is counter-current, but I have a question whether it is important from which side of the exchanger we connect the fireplace supply and from which the radiator circuit? My exchanger is mounted "upside down". It has a different connection (internal thread - No. 1 in the diagram) and the others have an external thread. In my opinion, hot water from the fireplace should be connected to this entrance, and for me this connection is connected to the radiator circuit. Or maybe it doesn't matter?
Please answer if I am right in all points. Thank you

The fireplace is not connected properly. The dish should be self complementary. Are you sure you drew the diagram correctly? The pump in the radiator heater in which direction has the arrow (on the pump body)? If down then wrong.

This exchanger is definitely too small. In addition, you would have to adjust the flows in the primary and secondary circulation. As the exchanger is too small, the fireplace system pump is as high gear as possible, and in the secondary circuit as low as possible.

gersik wrote:

The fireplace is not connected properly. The dish should be self complementary. Are you sure you drew the diagram correctly? The pump in the radiator heater in which direction has the arrow (on the pump body)? If down then wrong.

The pump is up so OK but I have a question the exchanger is connected against current only whether the left and right sides matter, i.e. e.g. to the left we connect the fireplace circuit and the right radiator circuit. Maybe it does not matter. Which scheme is correct? I just wonder why one exchanger has one connection and the other three are the same? Could this be the manufacturer's 1 entry mark

Exchanger probably a little too small, you need to build it to have access to filters, dump any zinc, the fittings should be black! I would not be surprised if the heat exchanger was partially overgrown as well as fittings