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To drain or not to drain?

YOu should always follow the advise of the manufacturer of your equipment.

Orange is the color of trouble in a warm water heating system. It is indicative of ferrous components rusting away as in the boiler, mixing valves, near boiler piping, circulator volutes and so on.

You need to discover whether the rusting is taking place BECAUSE (sorry, no italics) of regular flushing, or because the automatic fill valve is allowing FRESH WATER into the system because of hidden leaks.

The best water condition is black, dead water.

Call a professional and have the water checked. A detailed heating system water analysis is probably a good investment at this time.


  • Rodney Summers
    Rodney Summers Member Posts: 748
    Drain boiler periodically?

    I have a Weil-McLain WTGO-4 hot water boiler. My father-in-law says I sshould drain the rusty water from the boiler periodically. (The water is quite a orange-rust color). Yet, a tech at Weil-Mclain said not to drain it. They said that the less fresh water you introduce to the system, the better.

    I'm confused!!
  • JeffD
    JeffD Member Posts: 41

    Don't drain. The blacker and nastier the water the better. Everytime you add fresh water you add oxygen. Oxygen causes the corrosion, and the corrosion happens much faster at boiler temperatures. Also make sure your entire system is free from leaks. To much makeup water will kill a boiler really fast.
  • Chuckles_4
    Chuckles_4 Member Posts: 43

    The less water (and thus less dissolved oxygen) you introduce into the system, the better. But if you have orange water, you have a problem. There should not be that much rust. Probably you are losing water through a leak somewhere and the system is making it up with fresh water, thereby introducing a constant supply of dissolved oxygen.

    The Rhomar cleaning/passivating products are supposed to be good things, but I don't know how much they will help in cases as severe as this.
  • Rodney Summers
    Rodney Summers Member Posts: 748
    To drain or not to drain

    This is really good info guys. Here's the thing, about 4 months ago, we completed an extention on our house, and added about 80 linear feet to the baseboard heating system. Most of the system was purged, and of couse refilled when the job was done. Could the water still be orange from the fresh water added at the time?

    How long would it take for the water to turn black in a system, if of course there are no leaks causing fresh water to be introduced periodically?
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