Two boilers one installation - Installation diagram for two boilers

Hello all. I have a coal stove and want to connect two boilers for one installation. I drew a diagram of the current installation with a planned oil stove connection. I would like the furnaces to work together, but if there was a furnace failure or no fuel or fuel, one of the furnaces could work. In the attached picture, the dotted line is the one that I want to connect to the current installation. I am not a professional, please bear with me if there is something wrong. I am asking you for a schema evaluation and tips.

Oil boiler in a closed system? There must be a connection of both systems through the exchanger. There can also be both boilers in an open system but connected to the heating circuits by a clutch.

Hello, thanks for your interest, I made a second diagram, you could peek and evaluate, I added a plate heat exchanger, I want to connect it so that together one stove will fire, the other will fire, or two will work. I wonder if the oil stove will not work, the boiler will not heat the water, I think so. Is the rest of the installation from the oil stove to the boiler and the circulation is good. I will ask you if I can leave the boiler connected in the old installation so that I can use it and if I can do it without the heat exchanger and clutch. If I drew the diagram again wrongly, could you draw this diagram for me if it is not a problem. best regards

I asked if the oil boiler in a closed system because you drew it yourself in the first diagram. Make an oil boiler in an open system. Connect both boilers to the coupling and from the coupling to the installation.
http://www.letorex.com.pl/grafika/por_sch_14b.jpg
Here it is in a closed system. Remember about proper protection of both boilers.

Is this arrangement also ok?

http://test5sdkfsdf.blogspot.com/2011/07/raz-na-wegiel-raz-na-gaz-dwa-zroda.html

I suggest installing a cooling coil on the coal boiler and closing the system!

Hello, as in the title, I plan to add an oil boiler to the installation to convert it into pellets, I want to replace the fireplace with peas after the season, put a fireplace with a jacket. Now I want to connect the oil boiler with the smallest possible adjustments, but with the possibility of smoking one or the other, I have problems with the coal stove every now and then and I want it to be warm. I still found this diagram on the electrode. you can advise if this pattern will be good.

On a fireplace with a water jacket, you can also install a cooling coil and make the heating system closed.

At the moment I want to connect to the existing installation with an oil boiler open system, the fireplace is a planned change after the heating season. Is the last scheme good?