Near boiler thumping/puttering troubleshooting

PCapNJ

Hello HH Team!
I have an interesting noise that has developed and curious to hear if my assessment/analysis is logical and appropriate. I have a 1 pipe steam system, running very low pressure and overall system performance is great.

Currently, during some heating cycles, I hear a thumping/puttering sound that resonates through some of the house. When going to the boiler to investigate, the burner mostly drowns out the noise so it's difficult to pinpoint where it is happening. The noise happens BEFORE steam is generated as the header is not hot and I can 'feel' the puttering when my hand is on it. I equate the sound to an engine misfiring in case that analogy helps.

I thought it was vacuum of some sort, so I open my skim port and it still makes the sound with no impact. Sound stops once steam enters the mains and the system is 'warmed up.'

This never happened before, but only two things were done to the system that could be tied to it. I replaced a coupling that was leaking in my hartford loop and has to take off my drop header to do so and reinstall. Perhaps I didn't install it correctly?

The other improvement is that I went from an 11" unlined chimney to 6" stainless steel chimney liner for exhaust. Could this have caused it? I'm thinking of getting an expert in to perform combustion analysis? Is that the right test?

Thanks in advance for any thoughts!

Jamie Hall

Having changed the chimney that drastically, yes you should have a combustion analysis and adjustment with instruments done. Whether that is the source of the sound I don't know -- but it certainly should be done.

ethicalpaul

Since you say it is before steam generation it makes me think that you might have sediment at the bottom of your boiler that is causing "kettling" which is that the sediment at the bottom of the boiler insulates the water at the very bottom of the boiler (under/within the sediment) from the rest of the water, and that water would boil before the rest of the water and might make sound from the rapid collapse of the steam bubbles as they break through the sediment and hit the cooler water.

Just a guess

delcrossv

ethicalpaul said:

Since you say it is before steam generation it makes me think that you might have sediment at the bottom of your boiler that is causing "kettling" which is that the sediment at the bottom of the boiler insulates the water at the very bottom of the boiler (under/within the sediment) from the rest of the water, and that water would boil before the rest of the water and might make sound from the rapid collapse of the steam bubbles as they break through the sediment and hit the cooler water.

Just a guess

Easy to test, just do a quick flush and see what comes out.

Big Ed_4

What is the model of your boiler ?

PCapNJ

Weil McLain PEG-45 is the model.  

Good thought on kettling, due for a flush so I will look into it with a camera and see what may be down there.  Doubtful, since I built a wand thanks to this forum and have done some good boiler cleaning over the years but you never know.

I'm going to try to get an expert from this forum over and adjust the combustion for sure and hopefully go form there.