DIY almost works Flow problems though

[Nick Kendall]

Hello I have done allot of reading and studying still am struggling with the flow in my radiant heat system. I previously had it working great in my house then I got a bigger boiler and added my garage and am thinking I need a bigger pump

I currently have 9 loops of 3/4 pex Each within 10’ of 300’ to the manifolds
A pair of 5 loop manifolds one has house lines and the other has 4 garage lines I had it started last weekend with just my 9kw boiler but I found a 15kw a friend had so I switched to that and got it started up but it had a circulation pump on the bottom side so I just left it in place and am using my original taco 07 after the expansion tank My issue seems to be that I can only get flow to register through one of my manifolds at a time and when it flows it’s max if 1-2 when previously I was able to get more, and as soon as I try to turn open both manifolds I am not registering any flow on any meters
I have an f5 Nd f7 pump currently
I would think just a bigger pump but since adding the just a different boiler I lost flow pressure. Any help will be greatly appreciated thanks Nick Kendall

 

[Plumber69]

You must have something hooked up differently. is the send and return backwards. Is the pump pumping wrong direction

 

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[Nick Kendall]

Well I got the 1/6 hp pump I removed the xtra old pump and i removed the screen from the return side manifolds and it has tons of flow now Max’s out the guages thanks much.
In the mean time though I ran my boiler for a couple days straight and now it tripped the 60 amp breaker on either the boiler or in the breaker box. just getting started researching what could be wrong any ideas?