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Intense boiler noise on start up

This is surely a perennial favorite topic.
Quick background:
This is the 2nd winter at this house.
Boiler is 2008 Burham, gas.
Mains not insulated (It's on the list)
I've posted pictures in some of my earlier questions.
NBP not great but not terrible from what I'm told.
The boiler was silent when we moved in, but the water was green.
Had cleaning/service last winter and the water stayed clear, but the boiler (yes the boiler, not rads or mains) would bang pretty substantially unless I dropped the water an inch below 3/4 full in the gauge glass. It would also rattle like someone shaking a jar of metal BB's for a few minute until I felt the first bit of main get hot. I could live with that.
This past winter we didn't have it professionally serviced. I flushed, skimmed a few times, used Steamaster for while, drained/skimmed a couple more times. Now I'm on untreated water.
Problem
On start up the Boiler rattles like someone shaking a jar of metal BB's. This can be heard throughout the house, most loudly near the radiators, but the rooms are small so really everywhere is near a radiator. Then it bangs for 5-10 minutes. Each bang can be felt if you put your hand on the boiler, but the sound doesn't seem crazy loud standing right next to it. if you go upstairs, the noise is significantly louder and sounds far more concerning. Is it echoing and magnifying through the pipes/rads?
Question
What's causing this? scale/corrosion?
do the bangs cause damage?
are they indicative of existing damage?
What might fix it? I'm not against adding treatments, just not sure what needs to be addressed
Again, it was quiet when we moved in with green treated water then a little less quiet after a cleaning and now is't booming/banging on start up each cycle...then perfectly silent for the rest of the cycle.
thoughts?
Quick background:
This is the 2nd winter at this house.
Boiler is 2008 Burham, gas.
Mains not insulated (It's on the list)
I've posted pictures in some of my earlier questions.
NBP not great but not terrible from what I'm told.
The boiler was silent when we moved in, but the water was green.
Had cleaning/service last winter and the water stayed clear, but the boiler (yes the boiler, not rads or mains) would bang pretty substantially unless I dropped the water an inch below 3/4 full in the gauge glass. It would also rattle like someone shaking a jar of metal BB's for a few minute until I felt the first bit of main get hot. I could live with that.
This past winter we didn't have it professionally serviced. I flushed, skimmed a few times, used Steamaster for while, drained/skimmed a couple more times. Now I'm on untreated water.
Problem
On start up the Boiler rattles like someone shaking a jar of metal BB's. This can be heard throughout the house, most loudly near the radiators, but the rooms are small so really everywhere is near a radiator. Then it bangs for 5-10 minutes. Each bang can be felt if you put your hand on the boiler, but the sound doesn't seem crazy loud standing right next to it. if you go upstairs, the noise is significantly louder and sounds far more concerning. Is it echoing and magnifying through the pipes/rads?
Question
What's causing this? scale/corrosion?
do the bangs cause damage?
are they indicative of existing damage?
What might fix it? I'm not against adding treatments, just not sure what needs to be addressed
Again, it was quiet when we moved in with green treated water then a little less quiet after a cleaning and now is't booming/banging on start up each cycle...then perfectly silent for the rest of the cycle.
thoughts?
New owner of a 1920s home with steam heat north of Boston.
Just trying to learn what I can do myself and what I just shouldn't touch
Just trying to learn what I can do myself and what I just shouldn't touch
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Comments
Does this happen before or after the main vents close?
1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
One moment though...what level were you keeping it at where you experienced the banging?
I ask because 1" below 3/4 is still quite high so I wonder what it was before? Too high a water level can definitely lead to water being shoveled into the main especially with marginal near-boiler piping (like mine
It's a vapor system. My low pressure gauge (new this year) has never shown above 3 oz.
I've never checked the pH. Just regular pool test strips and water from the boiler drain should do it?
Just trying to learn what I can do myself and what I just shouldn't touch
Before that it was 2/3 to 3/4 full. He marked it on the glass, so I assume he filled it back to where it was before.
I've lowered it to 1/2 and I still get the banging.
Just trying to learn what I can do myself and what I just shouldn't touch
That may be where the popcorn sound comes from.
For the other banging, it could be that same cause (like the incorrect slope is causing water to get carried into the main), or there could be other pitch issues elsewhere in your system.
Were you ever able to get a good steam pro out to have a look?
I also had this noise in my old Burnham boilers--and would also get banging in them, just as the water began to boil. Both used Steamaster. Skimming didn't help.
What did work was Hercules Boiler and Heating System Cleaner. You can get it at the big box stores.
I had a gas guy in to clean a year ago. He has done steam installs and repairs and is listed on here, but I think steam work for him is still rare. The deal I made with my wife is that I'd clean/flush the boiler this year and then next year we'd pay the travel premium for a real pro (highly recommended here) to come out to make some system-wide assessments with the maintenance.
@Chris_L are you suggesting this
https://www.supplyhouse.com/Hercules-35-206-1-qt-Boiler-Heating-System-Cleaner-14603000-p
or this
https://www.supplyhouse.com/Hercules-35100-4-oz-Scout-Steam-Boiler-Cleaner-4-oz
I saw that the Boiler and Heating System Cleaner is siliconized. that struck me as an odd additive for a cleaner; I picture that gumming things up. I'm sure I have the wrong idea about that, but it threw up a flag for me.
Just trying to learn what I can do myself and what I just shouldn't touch
I don't know about its chemistry. All I know is that it is recommended for steam boilers and it worked.
I wouldn't recommend putting anything containing silicone in your boiler.
1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
NJ Master HVAC Lic.
Mahwah, NJ
Specializing in steam and hydronic heating
Just trying to learn what I can do myself and what I just shouldn't touch
NJ Master HVAC Lic.
Mahwah, NJ
Specializing in steam and hydronic heating
I've found on my own Burnham that it's incredibly sensitive to dirty water--both oils and suspended solids. My own boiler took about a dozen skims and flushes over the course of the first year after it was installed to tame it.
I didn't read through all your postings, but if the hammering you describe calms down initially right after a skim and then gets progressively worse over time I would recommend to keep skimming it.
18 Ounce per Square Inch Gauge
Time Delay Relay in Series with Thermostat
Operating Pressure 0.3-0.5 Ounce per Square Inch
Update:
Most recently, I drained out the half quart 8-way treatment and added another for a few days and then drained that out. Both times I got a LOT of fine rust dust settling out in the 5 gal buckets so the water was (is?) very dirty. It still banged, though not as bad. I'm inclined to repeat these cleanings with 8-way but I don't have any more at the moment.
I did, however, have a bottle of Hercules Scout. I added half a bottle of that two days ago and immediately the noise halted and it remains silent still. I'm not sure I like the idea of this leaving stuff in over the summer since it seems like it would settle out to the bottom over a few months of dormancy and I would fear it maybe crusting up , so I'll likely drain it out again. then keep repeating these cleaning steps going into next heating season.
With any luck, a few more cleanings/drains like this will get the the water to keep cleaner longer. since it never needs make up water, I'll be happy to get it back to more of a set it and forget it situation
Just trying to learn what I can do myself and what I just shouldn't touch
Do not be afraid to leave the boiler water treatment in the boiler over the summer. To prevent rust from from forming in the boiler over the summer fill the boiler with water to the top of the gauge glass.
Jake
by Jacob (Jake) Myron