Need Help Rebalancing a 1-Pipe Steam System

roc_rktec

Hey all,

We finally replaced our old, oversized, and incorrectly piped Utica boiler. Our new Weil McLain EG-40 (many thanks to all that commented and advised back in 2024) and its near boiler piping were a big improvement, and as part of the work, we reopened two capped main vent tappings. Years ago I went through the effort of balancing the system with the old boiler and only one functioning main vent, and so, I now need to retune everything.

I know I made some mistakes in the past, and so, am hoping to not knucklehead it up this time.

The system as it stands today is as follows:

Weil McLain EG-40 Boiler serving a 343.5 EDR System

Main	Piping Measurements	Air Vol	Radiators	Vent
Header	8' of 2" and 2' of 3"	.290 cf	n / a	n / a
1	2' of 2" and 16.5' of 1.5"	.277 cf	None	None
1A	14.5' of 1.5"	.203 cf	L1, P, L2	(V1) Gorton #2
1B	11' of 1.5"	.154 cf	F, G	(V2) Gorton #1
2	3' of 2", 6.5 of 1.5", and 3' of 1.25"	.190 cf	D, O	(V3) Gorton #1
3	3' of 2"	.069 cf	B, K	Converse flow

Rad	Main	Branch Piping	EDR	Valve
L1	1A	4' of 1.25"	42	Gorton #5
P	1A	14' of 1.25"	45	Gorton #6
L2	1A	2.5' of 1.25"	42	Gorton #5
F	1B	1' of 1.25" and 2.5' of 1"	55	Gorton D
G	1B	13.5' of 1.25"	36	Gorton C
D (t-stat)	2	6' of 1"	42	Gorton #5
O	2	21' of 1.25"	36	Gorton C
B	3	6' of 1.25" and 14' of 1"	21	Gorton #6
K	3	3' of 1.25" and 5.5' of 1"	24.5	Gorton #6

Current Issues/Symptoms:

• Uneven heat (no duh)!
  • Radiator F is the coldest, with B & K heating too quickly.
• Quiet puffing/whistling of radiator valves (skimming has diminished this, as several used to gurgle).
• Clicking/tapping water hammer in branch line to radiator O.

Initial Thoughts/Questions:

• To balance the mains: Install a Gorton #2 vent at V2, and install a second Gorton #1 at V3.
  • Is this venting capacity too rapid? Should I slow everything down?
  • Current vaporstat goes down to .5lb. Would getting down to 2-3oz really make a difference?
• Radiators B & K heat way too quickly, likely due to being on the converse flow main and having valves that are too fast.
  • Perhaps dropping from a #6 to a #5?
• Is there anything faster than a Gorton D for radiator F? Do I have to slow the rest of the system down to balance it out?
• Radiator D should be slowed down, due to t-stat being in the room.
  • Perhaps dropping from a #5 to #4

I am open to any and all feedback and suggestions.

Thanks!

Big Ed_4

Radiator venting , you need resistance upstairs to direct steam down the main first . We want to heat all the radiators the same time at first .. The steam will follow the least resistance way .. . I use the adjustable Hoffman . I first set the small radiators to A , medium to B and large to C. Don't over adjust , try it for a few days . All too loud raise them all up a notch . Room to warm , better to size smaller then opening the others .. Noise = too little venting and unbalanced to much venting …

dabrakeman

Great job of drawing up your system!

First check the pitch carefully on that line to radiator O. Any level area or sag that could collect a bit of water? Might also want to do this on the stretch of pipe 1b.

Seems like some big vents overall on not too big radiators. Gets very hard to balance when everything is venting so fast IMHO. I would start off dropping the vent sizes on those two radiators close to the boiler probably to 5's if not 4's.

You could consider another Gorton #1 at V2 but I really don't think you need it. You total main venting is more than sufficient for the volume of pipe it is handling. Looking at the situation where steam gets to the 1a/1b junction the total venting in the 1a direction (choosing 2oz cfm) is about 39% more than the venting in the 1b direction but to the end of the mains at least the pipe volume is 32% greater in 1a than 1b. So, maybe the main would fill slightly sooner in the 1a direction. The takeoffs to the radiators are quite short along 1a thus the slower venting on those rads vs F and G makes sense. I would try going slower on those before trying to find a faster vent for F and G. Just seems potentially something else is slowing F and G thus my suggestion to really check the pitch of 1b and the takeoffs to the radiators F and G.

Quite honestly if it were me I would tend to start out with everything ~ #5 and bump down initially on the overly hot and up to 6 on the cold. If piping is correct (pitch and pipe diameters which they should be if original) I don't think most any radiator should need anything faster than a 6.

ethicalpaul

Quite honestly if it were me I would tend to start out with everything ~ #5 and bump down initially on the overly hot and up to 6 on the cold. If piping is correct (pitch and pipe diameters which they should be if original) I don't think most any radiator should need anything faster than a 6.

In my opinion, this is the way. You can't do it with math. And change just one vent at a time (with Maid O Mist you can just change out the orifice on top of the vent of course) then see how it feels.

AdmiralYoda

Is this a mythical "Triple Header" system? Do I see a traditional header with a single riser….that goes into a bullhead-Tee header….which splits into two more bullhead-Tees that feed the two mains that are combined? Am I missing something?

Why couldn't they have split the two mains and fed each of them independently off of the new header?

Just a homeowner here so just trying to learn…not trying to sling anything at you 😊 I'm sure there were obvious reasons that I'm not experienced enough to notice.