What is my boiler spitting on my floor?

Hello,

I am a brand new user, and appreciate in advance any help I can get. I live in a rental, and don't know much about my boiler system. What I do know is that it is very old and inefficient (it's natural gas). Although the sticker is very faded, it appears to be a Weil Mclain CG-4. I came home and I found what certainly looks like oil on my floor. I was under the impression that the system heated water and pumped it through the copper lines in my baseboard, and didn't involve any oil. It feels, and smells like oil. It appears to be coming from a pressure relief valve on the side of my boiler. There is a link to pictures of it below. Any idea what it is? Thanks very much in advance.

only thing I can come up with is its cutting oil from the threading of the black steel piping or Its just really dirty water.

Strictly Service said:

only thing I can come up with is its cutting oil from the threading of the black steel piping or Its just really dirty water.

Click to expand...

It's anti-freeze.

If a system may be exposed to freezing temperatures, it's not uncommon to put (a special kind, not automotive!) antifreeze into the system to prevent that from damaging things. It does decrease the efficiency of heat transfer, though.

With any boiler, especially if there are any leaks and water gets added frequently, over time, the water can become pretty nasty.

It is just normal boiler water. Boiler water can be as back as ink. The one think that does concern me is that it appears that you have a discharge from your safety valve. I would suggest that you have a plummer check out your expansion tank, water filltrol system and safety valve, something is not good and it will happen again.