Gurgling Pipes

EF_4

when more of the radiator heats up with each cycle? We use day/night thermostat settings, so the system is cold when it first comes on in the morning.

Today, when the system cycled for the first time, very little of the radiator got hot. More of it got hot during the second cycle, and even more during the third cylce of the day. In fact, the air vented much better during the third cycle as compared to the other two. Nonetheless, there still was a gurgling sound each cycle. For all three times, I can hear the condensate rolling through the horizontal feed after the cycle ends. Is that normal? It was quite loud afer the first cycle.

EF_4

For many years, I've had a problem with spitting air vents and gurgling sounds associated with two radiators in my apartment. I live on the second floor of a four story residential building. The problem seems to have gotten worse this season. I have a one-pipe steam heating system. My boiler has a small crack, and has not been replaced yet. The problem I will describe predates the crack.

The two problem radiators are fed by a riser that is connected to another riser by a horizontal feed pipe that travels under my floor. In other words, a riser from the basement main feeds the ground floor apartment and crosses horizontally about 81 inches to another riser that feeds the rest of the building.

When the heat cycles on, I can hear the steam traveling in the riser. It sounds almost like a grinding sound, as if the steam is having trouble traveling. Further into the cycle, I hear a gurgling or sloshing sound or boiling sound that seems to be coming from the pipe underneath my floor board. I don't necessarily hear that sound at the beginning of the cycle, but it gets worse further into the cycle. This morning, it sounded like a stream underneath my floor board after the cycle had ended.

Early in the heating season, the two rads connected to that riser would spit water from the air vent. I had to turn off one radiator because it would spit so much water, and it would spit it high into the air. I left the other rad open b/c there was no other rad in that room. I put a large sponge underneath the air vent. Recently, that radiator has stopped spitting water as regularly as it did. It will spit once in a while.

A few days ago, I turned on the other rad, and it did not spit as much water and would get hot. It would just dribble from the vent as the rad filled with steam and heated up. This morning I noticed that the air vent on this rad just puffed and puffed when the steam came on, and only part of the radiator got hot. There were no water hammers during that time. I then heard that stream sound after the cycle ended.

When it was really cold earlier in the seaon, I did get some water hammers in that riser when the system turned on for the first time in the morning after being off all night. But we haven't had that problem recently.

The person in the first floor apartment keeps turned off the radiator that is fed by the riser that is connected to mine by the horizontal feed. During this season, he did turn on that radiator for a short time, and it worked fine. His air vent spit a little bit of water at the beginning, but after that his rad worked fine.

Does this sound like the horizontal pipe underneath my floor is sagging or back pitched? Or is there some other problem? I'm hoping to solve the problem without opening up the floor, but I'm fearing I will have to do that.

Steamhead (in transit)

I think you might be right

time to have a pro look it over. You'll need one anyway for the boiler replacement. Try the Find a Professional page of this site.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

EF_4

Can someone explain . . .

This morning, when the heat came on, the gurgling sound seemed to come from the radiator. The rad heated up mostly, and water dribbled from the air vent as the rad heated up.

If water was inside the rad, on the bottom, shouldn't I get water hammers as the steam enters the valve and runs into any water in the rad?

BTW, the water that dribbles from the air vent is clear, not dirty. Don't know if that matters in figuring out what the problem is.

LarryC

Gurgling radiator

Home owner here.

Could it be that the radiator vents until it heats up, but does not let air back in when the radiator cools? If so, then condensate fills up in the radiator and there is no way for all of the water to return to the boiler. The incoming steam bubbles thru the standing water, hence the gurgling sound. After the heat cycle finishes, unscrew the vent and see if you hear the air whistling back into the radiator, as the condensate drains back to the boiler.

Or, try to blow air back thru the vent when the radiator is cold. If no air flow back in, bad vent.

Larry C

The Wire Nut

I'll Try that . . .

but I don't believe that to be the problem. I've changed air vents many times, and the problem remains. Also, the rad is not heating up fully the first time it vents. It will vent air, heat up some, then pant and dribble water.

But even if you are right, shouldn't there be water hammering as the incoming steam runs into all of that condensate?

Craig_12

water noise

I have an older hydronic heating system, my issue is that I am hearing ever louder water sloshing through the baseboards. Any thoughts on what might cause this ?

thanks Craig

EF_4

Actually, I couldn't blow on the air vent because the end of the rad is too close to the wall. My head won't fit in the space. LOL.