Possible causes of these radiator sounds?

heatinghelp819

I would like to get an exhaustive list of possible causes of the following sounds. #1 (a and b) are coming from rad and main vents and lasts throughout the time the boiler is firing. #2 is coming from the radiator metal when it's heating up and again when cooling down (I think its expansion of the rad itself, not the feet on the wood or anything like that, so milk jug trick won't help). Both noises happen even with no setback/when heating only a degree.

Radiators are recessed and heavily painted over from years of paint. They are cast iron, including the frame which fills with steam (a couple pics attached). These noises are new following replacement of two leaking radiator valves, and are happening on most of the radiators throughout the house. Before this the system was relatively quiet.

I'd love to first start with a broad list of possibilities given this information and then narrow it down. Thank you!

1a. https://m.youtube.com/watch?v=75epDyvMjfM

1b. https://m.youtube.com/watch?v=gC9cFno7ZuM

2. https://m.youtube.com/watch?v=eumzFrS7DE4

(Sorry if this posts twice; looks like my first attempt failed)

JUGHNE

Even edited that is pretty brief.

JUGHNE

I screw up postings maybe twice a day.
The first vent sounds like panting of air in and out.
The second could be the same issue.
The third I believe is water hammer tinging in the rad

When the valves were change was any piping raised or lowered?
New valves are usually shorter in height than the old ones.
If I remember from Dan's book the panting is from water pockets being pushed back and forth, plunging air in and out of vents.
That water hammer could be from water not draining out of the rad. Are you sure that steam sized valves were used and not water only types?
What pressure is the system running at?

Smoke or flame near that vent may show you the air movement.

Steamhead

The heavy breathing is probably caused by dirty water in the boiler, or a water pocket in a nearby steam line.

The other one could be expansion as the radiator heats up.

HVACNUT

Like I said at other times, not a huge steam guy but that 2nd video sounds like Carol Anne in the T.V.

heatinghelp819

Any other thoughts anyone?

@JUGHNE after learning more, I had the same thought the other day about the sizing of the new valve, or whether maybe different sized parts were used which resulted in piping get pushed down, affecting their slope. I don't know the answer to that. I have some before and after pics, but the old valves were in such bad shape it's hard for me to tell. The pipes are also mostly in walls, so I can't see them. I have a call out to the person who did the work, but I'm sure he won't remember or will say (as he already has) that the replacement couldn't have caused this.

Abracadabra

Are the mains insulated?

heatinghelp819

Yes the mains are insulated.