Inside water loop options

FireMed

I had a system designed by a company but I am having troubles with it.

I need some advice on a change to my system.

The current system has a pump at the boiler feeding 4 in-floor heat circuits (all with the same size pumps!). When any of the inside pumps turn on, the outside pump is triggered to feed them. The issue I am having is that when the system activates the outdoor pump is feeding a fixed flow to either one, two, three or four circuits. So with one circuit, the pump outside is trying to pressurize the system. With 3 or 4 circuits running, they are working to draw more flow into the system.

My thought was to separate them into an outdoor and indoor system. The outdoor pump would feed a heat exchanger and the indoor pumps would draw heat off that system. Obviously, the outdoor system is open but the inside would need some sort of an expansion tank.

Another option that was just recommended is to setup the outside pump feeding a loop (manifold) that feeds directly back out to the stove. This is through an existing 1" pex pipe. The inside systems would draw off of that. The advantage I'm told is that the outside pump would be able to pump freely.
I don't know that this would work because as more pumps inside fire up, would they not just draw water from the return line to make up the difference?

The current system is not providing enough heat and this is one of the problems. I would really appreciate any experienced input on this decision.

Thanks in advance.

hot_rod

is this an outdoor boiler?
primary secondary piping or a hydraulic separator will keep the pumps from interfering with one another.

FireMed

Yes, it's outdoors.
I have never heard of "primary secondary piping".