What does it mean to \"FLUSH OUT\" my steam heating system?

tomd7735

If you have adjustable vents on each radiator, they are there to balance the system for radiators nearer of farther from the boiler. Over the years, they get adjusted. Probably out of whack by now.
What's nice, if you can afford it, are thermostatically controlled valves on each radiator. About $80 per, US$, last I checked.

dcha

what does that mean?

In talking with a friend, I mentioned that my gas-fired single pipe steam radiator system was having some problems with "even heat". While he was incredibly vague, he said that I should simply call a plumber and have my whole system "flushed out". He said that it's good to have a "maintenance flush" every 3 years to get all the "gunk" out of there. When I asked for details, he couldn't tell me more.

Is he just blowing smoke? Or is there truth in what he's saying? Thanks in advance for any wisdom on this topic! I love this website!

Brad White

Know thine enema

Granted the term "flush out" can be a bit vague.

When a system is started there is that bit, firing with TSP, skimming and repeating to get the oil out. That is a different procedure and subject.


What I think you are referring to, that over time all of that water an air creates a good bit of rust which then settles in the lower reaches of the boiler. This means the returns in most cases, some in the boiler of course, but really, any low point.

A good installation would have valves (full port ball valves) on the returns to which a hose can be attached. Better installations will have a valve at the other end to connect a hose. Plenty of ways to do this, but the key is to get out the mud that settles, gets churned up and settles in instruments, the LWCO and any place where it can do harm.

Some larger boilers (Smith Mills 4500 and 6500) had mud drums along the bases to give room for this to collect without issue but had cleanouts fore and aft to allow raking the stuff out.

Mind you, many systems never have this done and work for years and years without issues. Me? I like clean. Others may differ.