One-Pipe Steam system gurgles - upgrade in progress

Tom Hopkins

I just finished helping a relative out with their problematic one pipe system. If yours is working right, you should barely feel the air escaping from the radiator vents when steam is flowing to the radiators. If flow is stronger, then your mains are undervented.

There is some excellent discussion on venting radiators in each of Dan Holahan's books - I would definitely read at least one of them if you have not already done so.

Leah Frances

One-Pipe Steam system gurgles - upgrade in progress

The one-pipe steam system in my new-old-house was in need of some maintenance. So I:
1. pitched all radiators toward supply valve;
2. repacked leaky supply valves so they could be all the way open;
3. removed all old hoffman vents;
4. added new vents (varivents), valve bodies (honeywell), and TRVs (honeywell); and
5. insulated the naked supply pipes in the basement ($ouch$).

I also changed the thermostat for the boiler - many days it only comes on twice a day. But it is COLD tonight.

For all my work I am able to balance the heat (feel) in the house much better! No more overly hot or cold rooms!

BUT - BIG BUT - I now have gurgling spitting valves in my first floor radiators. Second floor radiators do not gurgle or spit. Tonight I slowed the varivalves down as much as possible.

I haven't replaced the main vents yet (I've bought the replacements) because I can't get them off the damn pipes.

Any thoughts about keeping my vents from spitting and gurgling? Or getting the main vents off their risers? Clearly I have some sort of condensate problem. What do I do? Help. I don't want all my hard work to be in vain.

FYI: boiler runs at < 1psi, and was installed 5 years ago, we had alot ($$) of work done on it this fall. I am worried that my return lines might be clogged (lots of iron in the water) but that will have to wait until spring until I monkey with it.

Long Beach Ed

As Gary Says...

Replacing the main vents would be a good place to start. Use two wrenches and penetrating oil. They'll come off. Then replace them with Gorton vents, which are much faster than most of the older main vents.

There are many piping problems that can also be causes. Just as Gary says, read the books and see if the near-boiler-piping is correct and if pipes are properly sized to the load.

Those are the solutions.