Can't identify sound from 1-pipe steam

michael_15

Within the first 5-10 minutes of my steam boiler starting up, there's a moderately loud sound which I can't identify. It lasts for a few minutes. It's not hissing, or banging, or gurgling. It just sounds like water is flowing. (I don't have an automatic water feeder, so I ruled that out.)

It sounds like, well, the sound that a toilet generally makes after you flush and when it's filling the tank. It's about as loud as that, too, assuming you're standing perhaps 10 feet away.

I'm not sure where exactly the sound is coming from; the pipes seem to transmit them around the house.

-Michael

David Efflandt

Water approaching boiling

Haven't you ever boiled a pot of water or used a tea kettle? As water approaches the boiling point, tiny bubbles form, but collapse before they can escape the not yet hot enough water. This makes sort of a rushing sound. It is like that, but on a larger scale.

Once the water gets hot enough and starts boiling with full size steam bubbles, it is quieter.