Hi all, first time here, and I'm hoping someone can shed some light on what i think is a problem. I'm heating my shop with a natural gas boiler, conventional type, via 3 loops of pex in the concrete in a single zone. Last weekend i fired the boiler for the first time to begin heating the shop. Everything went fine, no issues with producing heat. After about 36 hours of operation and the heating call being satisfied and maintained, i happened to notice that the color of my supply and return pex tubing to and from the floor had darkened. Out of concern, i powered off the boiler and shut off the gas and allowed the system to cool so I could take a look at the water/glycol. Once it had cooled, i attached a hose to the boiler and drained about 2 gallons into a clean white plastic bucket. The glycol was as black as tar!!! I've been reading myself death trying to figure this out. I'm being lead to believe its corrosion/iron oxide from the cast boiler.... This fast? After letting the bucket of glycol rest a few days, the liquid cleared and the bottom of the bucket was covered with a layer (approx 1/8" thick) of thick black substance. So for fun, i took a magnet to the outside of the bucket and sure as I guessed, the sludge pulls to the side of the bucket, so its definitely containing iron. My boiler is cast, floor tube is oxygen barrier pex, pump is cast, and connections are 3/4" copper.
Guys help me out here, is this normal? I feel at this rate i'll have no boiler left by the end of the season?
The glycol mixture was approximately 40%.
Guys help me out here, is this normal? I feel at this rate i'll have no boiler left by the end of the season?
The glycol mixture was approximately 40%.