Water trickling sound after boiler turns off - normal?

JH3550

Hi! I am at a house that is not my own, and I observed the following:
After the thermostat is satisfied and the boiler shuts off, I heard what sounded like water trickling into the boiler. I’ve never heard this before in my one pipe system. Could this be condensate dripping into the boiler? Is this normal?

One pipe steam.
Natural gas boiler.
House built in 1896. 
the system runs ok, but could use new main vents and radiator vents (they haven’t been replaced in at least 25 years and probably longer.) a couple of the radiator vents hiss loudly. 

I also could see steam coming out of one of the main vents. I think it would be wet steam; it was visible like what you see when a shower is running. 

Thanks for your wisdom!

neilc

post another picture floor to ceiling from that right side,
need to see what n where the header supply connects to existing at the ceiling, and what all that old insulation piping is doing

JH3550

@neilc like this?

EdTheHeaterMan

Somebody didn't look at the instructions

Big Ed_4

What you hear is the condensate trickling back from the dry return...

neilc

EdTheHeaterMan said:

Somebody didn't look at the instructions

What Ed says,
you're sending wet steam up into the system,
and I'm betting you're hearing all that condensate make its way back, on the dry returns where they drop back down to return,
does that bullhead main pitch away, both ways, from the header riser?

EdTheHeaterMan

It would be normal for your system. If the installer followed the instructions.

Edit: Found better illustration for YOUR boiler.
That noise might not be so obvious. But there would still be condensation returning to the boiler, so it may not go away completely.

neilc

@EdTheHeaterMan did you modify that picture?
(surprised to see that bullhead at the end of the header)

EdTheHeaterMan

neilc said:

@EdTheHeaterMan did you modify that picture?
(surprised to see that bullhead at the end of the header)

No I didn't, that is out of a newer version. I thought that was odd also, but I found a better illustration that better matches the OP's boiler. Here is the original illustration from my post so folks know what your are talking about. But it looks like it should work as a second or alternate main location as far as steam and condensate are concerned.


It's on page 11 of this document.

JH3550

does that bullhead main pitch away, both ways, from the header riser?

Hard to tell with the insulation and the only level I have with me is my phone (this is not at my own house). It’s reading level FWIW

JH3550

Oh dear, i’ve read a lot of posts on here, where someone asks a question and the answer is “your boiler is piped wrong,” and now it’s me! This is not at my own house. it’s at a family member’s house, so I don’t get to make the call on what to do about it. 

Given that the near boiler piping is incorrect, is it worth replacing the main vents and radiator air vents or will they just be filled with water and messed up quickly?

This started because the upstairs is getting hotter than the downstairs. I thought I would replace the main vents and the radiator air vents since they are decades old, and then balance them to get the heat more even.

thank you everyone for your replies!

neilc

you teased us with trickling water, and pictures of a boiler not piped quite right,

the vent(s) that pass steam(vapor?), will they close eventually, as hot steam reaches them?
and for the hot upstairs, slow those vents down, you may not need to change the whole house,

back at the boiler,
what pressure does it get up to?
has the pigtail and connecting piping been checked and serviced?

EdTheHeaterMan

Ten years is a good life for a steam vent. It will be time to retire them soon. When you start to do that, think about adjustable vents for each radiator. That way you can slow down the upstairs and increase the down stairs. But once all the vents are closed, if there is a long call for heat, the size of the radiator will determine the amount of heat that it puts out. As the steam condenses and draws more steam in, the radiator will stay hot. until the call for heat stops the burner.

Where is the thermostat located? In a colder room? Then the call for heat will be long. If you can get that room warmer faster by venting that radiator faster, that may help. But if the radiator for that room is just too small... then you have to figure out a different way to reduce the heat in the other rooms. Lots of tricks to do that are available. Radiator covers, Thermostatic radiator valves place on the vents. Sometimes you just have to turn off that radiator in the room that is too hot.

Or you can do what they do in New York City... Just open the window! LOL

JH3550

neilc said:

you teased us with trickling water, and pictures of a boiler not piped quite right, the vent(s) that pass steam(vapor?), will they close eventually, as hot steam reaches them? and for the hot upstairs, slow those vents down, you may not need to change the whole house, back at the boiler, what pressure does it get up to? has the pigtail and connecting piping been checked and serviced?

The pressuretrol was set at between 2 and 3 for cut in with a differential of 1.5. I changed it today to ~.5 and a diff of 1. The 0-30 psi gauge is now reading below 1 (fwiw, I understand from reading this forum that those gauges are not great at low pressure). 

No idea if the pigtail and piping have been checked. Probably not. 

My plan was to replace the vents, slow down the 2nd floor vents and adjust the first floor vents to get the heat more even. I was just wondering if the incorrect piping and wet steam would wear out the vents faster than under the correct conditions

thank you everyone!

neilc

dialing the Ptrol down is a good move,
that you see a difference on the gage suggests the pigtail and pipe is working, check it when you can.

wet steam itself won't wear out the vents,
if it's carrying up dirt and grundge it might foul a vent though,
some vents respond to vinegar or CLR baths to clean and clear them out,

I don't see a skim port,
does the water jump much in the sight glass?

JH3550

The water moves in the sight glass about an inch or so. It bobs; doesn’t seem wild or dramatic. 

I haven’t been able to tell whether the main vent closes; the thermostat was calling for heat and then shutting off the boiler after just a couple of minutes, a bunch of times per hour. I went into the thermostat settings and it was set for hot water 🤦🏻‍♂️. I changed it to steam.