Replaced iron radiator pipes with non-barrior pex. Trouble?

I bought my first house in April and went right to work finishing the basement. It's a 1925 house with a 10-20 year old boiler connecting to the original pipes leading to the 7 cast iron radiators. The original pipes that fed the radiators hung quite low so the first step was to remove them. We built two manifolds (supply and return) with 7 valves each leading off the boiler. We then ran PEX from the manifold to the radiators.

It has worked perfect, with great control on room heat by controlling the valves. Problem is, the city found out, is making us pull a permit, and I hear that we used the wrong kind of PEX. I hear with any iron in the system, you want to use PEX with an oxygen barrier otherwise the components can rust. Is this really something to worry about? And is there code saying that I need oxygen barrier? The last heating guy I had to bid was confused.

Even if it passes an inspection, do I still want to replace it? (gosh I hope not) Thanks for your thoughts!

(ps - if you're thinking about doing this, I totally recommend it, except for the wrong PEX part)

 

Replace it. The PEX you are using will allow oxygen into your heating system. The oxygen will cause your radiators and boiler to corrode.

 

PEX tubing with an oxygen barrier must be used when ferrous components are present in a radiant heating system. If an oxygen barrier is not used in these systems, the ferrous components will rust. However, if a radiant heat system does not contain ferrous components standard PEX tubing may be used. The above is copy and pasted, I was a little curious my self as i have never used it.

Trying to think of what radiant heating system wouldnt have ferrous components, Solar maybe?

 

It must be replaced. The boiler will fail and all other ferrous items such as the pump, expansion tank. flo valves, air separator etc if they are ferrous.
You could install a heat exchanger to protect the boiler but still does not protect the rads etc.