No oxygen barrier in radiant floor heat

[JOE1943]

I installed a radiant fl heat,350ft of pex (no oxygen barrier) ,ran it off gas hot water heater.5 Years later I'm installing a gas hot water boiler for BBHW, taking out hot air.The question is will I have a problem with rust in the new boiler when I connect the low temp radiant heat .I should of used a oxygen barrier but nothing to saying except I was DUMB.The new boiler will be gas,hot water ,150 temp ,3 or 4 zones,mixing valve,pex(with oxygen barrier) and copper.I thought I posted this already but can't find it so I'm doing it again.

[Ed Janowiak]

If you're concerned about this existing loop buggering up the new boiler, isolate it from the rest of the system with a plate type heat exchanger.

[fire]

Yes .isolate te rad. loop it will mess up the system if you dont. it will need separate boiler feed, expansion tank, and rust proof pump.