Odd skimming results?

adasilva

Skimmed my boiler this am and all went well. Drained the boiler to proper level and ran it to see how the water level would be as it runs. Water level was steady and with about 1/2" of movement, which I assume is good? Odd thing is as it ran, my low pressure gauge didn't show a any readings. The water has now turned rusty as it has now come up to temp. Any thoughts on this would be helpful. Any steps that I may have missed?

Danny Scully

Skim some more!

adasilva

@Danny Scully I'm thinking that it's residual crap from the bottom??

JUGHNE

Could your pigtail for the gauge be plugged from the relocation of sludge within the boiler?

JUGHNE

Looking at your pigtail picture and if that is your skim port I would guess you collect stuff in there.
Would be better to turn the 1/2" tee up and reconfigure the 1/4" piping so it is above that point. IMO

Fred

If the water line is stable, just drain the boiler, flush it out as best you can and refill it. Skimming won't remove any crap laying on the floor of the boiler. If you are sure the pigtail is clean, little to no movement on the gauge is not a bad thing.

adasilva

@JUGHNE makes sense to me. In the interim I'm thinking I just tighten the 3/4 T so the gauge and ptrol are at 10 o'clock?

adasilva

@Fred I believe that the whole idea of skimming is to keep the water line from jumping around. And I will pop off the gauge as I'm skimming to verify that the pigtail is clear but I just did all that last weekend to set this up so I'm almost positive it's clear!

Fred

adasilva said:

@Fred I believe that the whole idea of skimming is to keep the water line from jumping around. And I will pop off the gauge as I'm skimming to verify that the pigtail is clear but I just did all that last weekend to set this up so I'm almost positive it's clear!

Yes, I went back and looked at your new set up. The little rust color may clear up with a drain and refill although most dead men expected a "Tea" color to the water. It otherwise looks clean and I suspect some don't see that coloring because we add a Steamaster tablet or two which is a light purple and probably masks that tea coloring. It is raw cast iron and water after all. Good job on the skimming!

adasilva

@Fred thank you sir! No better feeling than to accomplish a project with positive results.

adasilva

@Fred so skimming has increased the amount of wet steam...... listening to my vents gurgle as I type. Thinking the piping with the equalizer before the takeoff is what's the issue now. Pressure is at about 1/2 lb till the end of the cycle, just saw 1 lb but t stat was satisfied and knocked it off. Going to move my main vents higher than what they are now see if that gives me any gains. Water level is solid though.

Fred

Wet steam/gurgling is probably not related to the skimming you did.
Check:
- That the system pressure is actually correct. Do you have a 0 - 3 PSI gauge on the system? The 0 - 30 PSI gauge is never accurate at low pressure.
- Did you clean the pigtail and make sure it is not plughged?
- Are the radiators that gurgle pitched back towards the supply valve?
- And the dreaded last question: Is the boiler piped correctly, so that water can drop out of the steam, into an adequate header that is pitched to an equalizer and then down the equalizer?

adasilva

@Fred ok so all the rads tend to gurgle at times. Even the furthest one from the boiler. Since I've skimmed the farthest radiator heats up the quickest but that also has a mom c vent on it. I did that because in the beginning I was unaware and followed the card details on the vent. They actually tend to tell you to utilize a different vents due to locations from the boiler and in the house ETC. As previously discussed I did clean my pigtail when I removed it to put in the skim port setup.
I do have a 0 to 5 pound pressure indicator on the pigtail with the ptrol. I'm aware of the issues with the 30 PSI gauges on the boilers being basically a plug. It tends to run at about a half a pound but when it was hissing and gurgling when I wrote my original post it got up to 1 psi. I have posted my boiler piping before and told that it was wrong. For some reason whoever installed it put the equalizer before the take-off to the main and it should be after.
What perplexes me about it is that I just got home and my wife turns the thermostat back only 2 degrees and it's been fairly chilly today and I turned it up and it ran fine with very minimal gurgling just now. I'm debating about picking up 9 Hoffman # 40 for the radiators themselves and see how it operates after that.

Fred

Depending on the type/size of the radiator vents, they can cause some gurgling If the vents are too aggressive. Refresh my memory, do you have good venti ng on the mains? That can also pose a problem. I think slower radiator vents may help some. I doubt that putting #40's on all of the radiators will balance each room, like you want. At the end of the day, probably the best (real) fix is to get the near boiler piping corrected.

I'm guessing that the skim removed the oils off of the surface of the water, allowing more bubbles to burst and release steam up into the header/mains. Being wet, because of the near boiler piping situation.

adasilva

@Fred I have about 55' of 2" main with 2 bj big mouth vents and I have a mom main vent with a d orifice laying around that I have a spot for in my antler piping so why not add it, right? 👍 With the coming time off for the holidays I plan on reconfiguring my antler to raise it up probably three more inches and add in the maid of mist vent. I agree with your thoughts on the wet steam being pulled up into the main due to the bad piping. The boiler was installed in 2006 and I'm dying to do a dropped header and move the equalizer to where it belongs but my line of work doesn't allow me the time to do it in the warm months!

Fred

@adasilva, the two Big Mouths are more than enough for 55' of main. The Maid-o- Mist won't get you enough to even worry about it. It will just be something that will fail, fairly quickly.

neilc

the "is the pigtail clear" question still stands,
even though you have that 3# gage with the Ptrol, it is only telling us the pressure on that side of the pigtail,
if pigtail is not clear, you could still be making 5/10/?? on boiler side of pitail

Fred

@neilc , he did take his pigtail off a week or two ago and cleaned it out, along with adding a skim port.

neilc

my bad,
missed that,
see it now

Fred

@neilc , Don't feel bad. I missed it too and he told me a couple times

adasilva

@Fred OK, since I've skimmed the boiler the heating time has dramatically increased easily 10 min per cycle. The water level is smooth as butter but there are random drops that come in from the top of the site glass as it runs. Also the pressure doesn't show until about 15 to 20 min into the cycle and stays steady at about 1/2 lb until the very end of the cycle and then I have seen as much as 1.25 lb. Another oddity that I have noticed is the radiator that I have changed out the leaky pipe on is now the last to get hot. I have a total of 9 units two of them upstairs. The one I repaired is #4 in line from the boiler. Number 9 (last on the run) gets hot the quickest. Would the equalizer pipe being before & not after the take off to the main be the cause for all these issues?

Fred

@adasilva the water droplets at the top of the sight glass are an indication that the boiler still needs some additional skimming.

The way the radiators heat could be the result of the way you have balanced/vented the system/radiators.

While the system pressure is well within acceptable ranges, some of the pressure at the end of the cycle could be the result of a boiler that is a bit larger than the connected EDR. What is the Boiler output and the total Radiator EDR?


I think the biggest issue with the equalizer being on the wrong end of the header is probably wet steam. Also water droplets having to fall back into the boiler through the boiler risers instead of the equalizer..

adasilva

@Fred My total EDR in sq feet is 316.75 sq. feet the boiler is designed for 375.....So it is a little on the bigger side but not all that bad? I flushed more crap out of the boiler today after I had to redo my antler for my main vents as it puked out water as I was working in the basement. I'm embarrassed that I overlooked the pitch while trying to gain height . I also agree with the venting that I have done. I'm using MoM vents and can swap out the orifices to try to tweak them.

adasilva

@Fred OK so I did another beginners oversite.....not figuring in the pick up factor of 1.33. That gives me 421.27 sq feet of EDR and the unit sized at 375 which makes it undersized. I believe that this could be the reason for the long cycles? Man the more I learn the more frustrated I become lol

ChrisJ

adasilva said:

@Fred OK so I did another beginners oversite.....not figuring in the pick up factor of 1.33. That gives me 421.27 sq feet of EDR and the unit sized at 375 which makes it undersized. I believe that this could be the reason for the long cycles? Man the more I learn the more frustrated I become lol

The equalizer on the wrong side of the header is a huge issue, it makes the header useless as it'll backup with water.


Whats your boilers DOE output rating? The rated sqft of steam already includes a 1.33 pickup.

adasilva

@ChrisJ 120 MBH per the label

adasilva

@ChrisJ correction 90 MBH steam.....

ChrisJ

The net rating is 375sqft of steam.

Net meaning it includes 33% over for pickup.

It's 120,000 btu/h output gross which means enough, in theory, for 500sqft of radiation assuming absolutely no piping losses.

Fred

@adasilva , You did not make a mistake, the 375 Sq. Ft. rating on the boiler plate is the number you want to use to compare your connected EDR. You are a bit over sized but we've seen much worse. That is manageable. We have already discussed the problem with the way the header/equalizer is installed and the consequences of that configuration. It is what it is until you have an opportunity to correct that, it will cause wet steam. In the meantime:
- skim the boiler again
- Re-balance the radiators
- Keep the system pressure as low as possible which means no set-backs or anything that will cause extra long heating cycles.