Changed the Main Vents, but Radiator Vents still sing

ccordero

Had a problem recently where my radiators were singing very loudly. I ended up replacing the main vent with new Gorton #1s and the radiator vents with Gorton #5s.

When the call for heat ends, I can still hear an annoying whistle coming from the radiators. It's not as terribly loud as it used to be (it would hurt my ears), but still loud enough to be annoying.

What can I do to fix this? I wanted to use a a Gorton #2 on the main vent, but it's simply too big for where I'd need to install it. Is it possible to use multiple Gorton #1s? I saw in pictures on the internet that some bigger buildings placed multiple air eliminators, in a T shape where a single vent used to be.

Part of me thinks that that would be overkill though. My house is not a mansion. Are there other things I could do?

jhewings

Since this happens after the cycle is complete, I believe you are hearing air rushing back into the radiator vents. The steam collapses causing a vacuum. This happens at my house and there is a fairly loud sound at a riser vent, although not as annoying so I have not tried to stop it. I have read that adding a vacuum breaker next to the main vents can solve this.

Long Beach Ed

Make sure your steam pressuretrol is set as low as possible. If it is, consider the vacuum breaker jhewings suggests. Have you checked to see if the boiler is terribly oversized?

KC_Jones

Unless your main is less than 10’ long more main venting would be worthwhile.  I’m running 4 Gorton #1 on a 25’ main and 2 on a 15’ main.

ccordero

Pressuretrol is set to basically the lowest setting. How would I know if the boiler is "terribly oversized"? It's a brand new boiler, installed in July 2022. I haven't had any hint that it might be oversized though.

I have two main vents, both are around 25' each.

KC_Jones, would you be willing to share pictures of your 4 Gorton #1's? I'm not sure how I would install more of them for me.

KC_Jones

ccordero said:

Pressuretrol is set to basically the lowest setting. How would I know if the boiler is "terribly oversized"? It's a brand new boiler, installed in July 2022. I haven't had any hint that it might be oversized though.

I have two main vents, both are around 25' each.

KC_Jones, would you be willing to share pictures of your 4 Gorton #1's? I'm not sure how I would install more of them for me.

In my opinion if the boiler is being shut down by the pressuretrol, the boiler is oversized or you are seriously low on venting, depends when it cuts it out. Both things could be true, oversized and too little venting. The pressutrol is a safety not an operating control. Based on what we see here, sizing is done wrong by a majority of contractors.

I don't have pics of my vents, but here is a thread showing one.

https://forum.heatinghelp.com/discussion/181621/main-vent-antler

EBEBRATT-Ed

Your getting the noise when the boiler shuts off. That is the steam in the radiators, boiler and piping condensing back to water. Steam condensed back to water changes in volume 1700 times. Picture a box 28"x 28"x28" filled with water. When that box changes to steam it would take a box 28' x28'x28' to contain that steam.

Your venting may be inadequate, how does the house heat and how long for steam to reach the radiators?

When the boiler starts on a call for heat hod your hand on the steam header and when it gets too hot to hold start timing. See how long it takes for steam to get to the end of the steam mains.

To eliminate the noise issue put a vacuum breaker or a y pattern check valve on the boiler on any tapping above the boiler water line. This is a simple job.

Tunstall sells vacuum breakers, or you can get a check valve at a plumbing supply house.

EdTheHeaterMan

Changed the Main Vents, but Radiator Vents still sing
This is the first time I ever remember anyone telling me about a heater singing...
I have always told customers who called to tell me the heater is Humming that the heater probably forgot the words... This is something I have never encountered. Perhaps it is just that season for singing!