Boiler, Entran Onix plugged

[Jerry]

My system is a hot water baseboard, all 3/4" copper pipe, multi-zone with separate circ pumps, built in 1998. There is some corrosion on the boiler and I'm researching replacements. I run an OA reset 150-180 and an indirect domestic hw tank. I have three Smith KS2008 hydronic kickspace heaters piped in parallel on three of the zones with mono-flo tees. The heaters are connected to the system via Entran Onix 1/2" tubing. Every single one stopped working and I found them plugged with rust deposits. I have no other evidence of this in the system and flow through my baseboards is good. Has anyone come across this? Where would the rust deposits come from and why would they accumulate in just the Onix tubing? Would you recommend using new Onix piping as a replacement? I don't have much room to work with for PEX or copper.

 

[Fitter30]

Low flow in a system will catch all the dirt and corrosion in a system. Fin tube has more flow thats why it's cleaner. Your water chemistry is way off. Water stink? Flush everything out including fin tube and boiler forward and backwards. Pull the pressure relief valve off and dump some treatment in before refilling system. Has the system had alot of fresh water added over the years because that adds oxygen causes the corrosion.
https://www.supplyhouse.com/Rectors...MI8sPZlZb_6AIVh7zACh3fCAnnEAsYAyABEgKVYvD_BwE

 

[Sponsor]

 

[Jerry]

Low flow in a system will catch all the dirt and corrosion in a system. Fin tube has more flow thats why it's cleaner. Your water chemistry is way off. Water stink? Flush everything out including fin tube and boiler forward and backwards. Pull the pressure relief valve off and dump some treatment in before refilling system. Has the system had alot of fresh water added over the years because that adds oxygen causes the corrosion.
https://www.supplyhouse.com/Rectors...MI8sPZlZb_6AIVh7zACh3fCAnnEAsYAyABEgKVYvD_BwE

WAter doesn't smell but I did do some work and had to drain down some. I'll look into the treatment options.

 

[WorthFlorida]

Found this 11 year old post. It sounds similar to your problem.
https://forum.heatinghelp.com/discussion/124690/onyx-radiant-tubing