Outdoor Coal boiler

[Transporter]

Im changing out my glycol in my boiler cause the PH has dropped too low and I have had a steel fitting corrode and start leaking.The glycol that leaked out was dark colored and PH very low.When I went to the boiler and started draining it the glycol there seemed to be almost clear but when I blew air through the lines and took the return line off it came back black.Why wouldnt it all be mixed around the same color does the corroded metals just stay in the lines that are down low in the basement???

 

[Blu Du]

could be electrolisyls, fixed by a better ground. see it all the time with well pumps on the older 2 wire with no ground motoers. all fittings should be brass copper or stainless

 

[hilinerider]

when the additives in antifreeze break don the color changes and they drop out, triethylene glycol used in dehydators changes color if it is over heated

 

[Transporter]

Its propolyne glycol.The nipple that corroded was steel that was between the main circ pump and a brass ball valve the lines coming into the house are plastic coated copper pipes ivec piping or somthing like that there is some coper piping around the furnace and zone pumps.I just dont understand why the difference in glycol at certain points in the system when in circulates throughout.