"Jordan" wrote in message
. ..
I have three floors in my house, all with base board heaters. Each loop is
a zone. They all come off my Burnham oil furnace.

I had to drain the system to replace a section of pipe on one of the
zones. When the water drains out it comes out really dirty. I know my
water is a little hard so is this normal or do I need to add something to
the water in the loops when I fill it back up?

It is normal. That water has been in there for a long time along with any
internal residue from the tubing, boiler, etc. .

Oh, you don't have a furnace, you have a boiler. Furnaces heat air.
Boilers heat water.