Main vent on the riser...in my living room?

paserafi

Happy New Year everyone. I've been putting a lot of time and work into getting my single-pipe (opposite flow) steam system into comfortable, efficient, and quiet working order. Most of my research has been on this site. The major changes I've made are

1) Lowering the differential Pressuretrol settings:

-previous: 2psi cut-out and 2psi cut-in (which made no sense to me)

-current: ~1.5psi cut-out and ~1.0psi cut-in (approximate because the scale is blank below 1.0psi which is annoying).

Once that simple adjustment was made, I noticed an immediate improvement in steam getting to the risers faster, but still about a 40 minute radiator warm-up cycle (boiler running the whole time) and clanging and banging in the 2" main, 1.5" runouts, and 1" risers...and in the radiators. I should mention the pitch of the main is great, and only 2 out of 7 runouts are pitched less than desireable but pitched nonetheless.

2) Replaced all radiator vents (7 total, 950sq ft condo) with Gortons. Although they sound like they work over-time, the venting "cycles" line up with what I would expect (air coming out at beginning of heat cycle, air being sucked back in at the end of the cycle). So no clogging/sticking. On the furthest radiator (about 30' of pipe from the boiler) I used a Gorton#6 angle vent and that guy vents like crazy. Radiator heat-up time reduced a little but boiler just ran and ran and ran, but at least that far rad heats up now.

3) I insulated everything after having some left-over sketchy asbestos removed. Radiator heat-up time is now down under 10 minutes. Clanging reduced about 95%. Timing of all 7 radiators venting is within a minute of each other which is 1000% improvement over the H.D. cheap-O vents. But the venting is loud and in some radiators, sometimes, I hear gurgling and hissing (a little spitting) at the vents.

So the new (or more prevolant) sympton is the loud vents, rushing sound of air, some whistling on both ends of the cycle, and I think short-cycling (at zero internal boiler pressure, and thermostat reading the same as the set temp, the boiler fires up and the vents start to sing while everything is still nice and warm).  Here's my plan:

4) new thermostat (Lux 1500T has good reviews, nice features, well priced)

5) add a main vent (none currently, or ever, on this system). I had a plumber with 30+ years of steam system work in the Boston area (a fan of heatinghelp.com and Dan's books that he saw on my coffee table) come do an assessment. He observed for about an hour and a half. Boiler size is close, a little over. Checked pitch everywhere, recommended a lift of one radiator, which bought about 1.5" rise on a 10' run out, so it's pitched better now. Told me to insulate, so I did. Said a main vent could help, but it might also cause problems like steam moving TOO fast to some risers and carrying too much water (water line to horizontal main is 38" so it should be dry...site glass hardly moves at all and is clear/dry). He said he could install the Gorton#2 I prematurely bought, but it would be pricey to re-pipe due to the winding, cornering, tight squeeze that is at the end of the main, before heading out to that farthest radiator. He said a quick, cheap "trial" would be to install the Gorton at the top of the riser for that radiator, in the living room.

Thoughts on his assessment and my plan? Would a main vent cure the over-worked radiator vents and eliminate the gurgling and hissing, and would a main vent at all affect the short-cycling? Or is that more related to possibly a flaky thermostat and/or pressuretrol? I've noticed the boiler takes a long time to reach the 1.5psi cut-out...usually heating the house from 63 to 68 degrees happens first and takes 30+ minutes. The radiators get hot fast now but the ambient temp creeps up slowly (according to the cheap honeywell) and the boiler runs the whole time. Once I observed it cut out at 1.5psi before the house reached the set temp, but that might have been a very cold day. Finally, is the "main" vent at the top of the riser a reasonable option, or will this cause problems?

Thanks, and apologies for the long-windedness.

BobC

Venting

IOt sounds like the installation of an air vent on the steam main might cure a lot of your problems. It will vent all the air from the boiler and the main without forcing it all through the radiator vents.



The Gorton #2 is a physically large vent and may not fit all applications, Post a picture of the venting location and maybe someone will see a way to do it without entailing a lot of work. If that radiator is the last on the main you could vent it like that as long as you don't mind having a large copper vent sticking up there.



The alternative might be to use one or two Gorton #1's, they vent at about 1/3 that of the #2 but maybe you don't need that much venting., If your total main 30 ft long (what size pipe is that?0 you will probably need 2ea #1's if not the #2. Maybe you could sell the #2 to recoup some of that money you've already spent.



Once you have the main vent in place you might find the gorton #6 to large for some radiators but lets wait to see what happens.



Bob

paserafi

will post pics tonight...

Thanks BobC, I will post pics tonight of the locations where the main vent would fit, satisfying the 6" rise requirement (if that's a real thing). One location being above the floor in the living room. And yes, that is the last radiator on the main. I share the same thought that the Gorton#6 might end up being too large once I vent the main, but that bridge is off in the distance still.

paserafi

Pics of potential main vent locations

Attached are the pics of the radiator and the piping right below it. The 1" riser drops below the floor into a 90 which joins it to a 1.25" pipe that spans 2 joists (both are notched to accomodate).  The 2nd 90 elbow turns the 1.25" pipe parallel to the joists and runs over the top of the center beam for about 3' (third pic) and pops out on the other side (fourth pic) into the 3rd 90 which connects to a 4th 90. This is where the run-out meets up with the main which is 1.5" pipe heading back towards the boiler. After 6' of 1.5" pipe it expands to 2.5" pipe for another 16' where it joins the header above the boiler.



The main doesn't terminate at a dead-end after the last radiator run-out to riser. It makes those four 90deg turns, reducing the pipe size from 1.5" to 1.25" and then finally into the vertical 1" riser.



The only locations with enough headroom for the Gorton#2 vent is at the 3rd and 4th 90deg connections, replacing the lower elbow in fourth pic with a Tee. Or at the top of the riser (Tee on the riser, gorton#2 on top vertically, install horizontal gate valve for radiator).



Plumber also suggest move the radiator to the left (in first pic) which puts it closer to the main. Eliminate all those 90s and the 1.25" section of pipe and just have the 1" riser drop down to the main, with only 1 bend into a Tee, with the main vent on the other side of the Tee. This would be costly, as I dont have the tools or skills to cut and thread black pipe.

J.A.

a few things

In your original post you mentioned that you insulated your pipes, but your pictures show bare pipes, are the pictures just old?

Also, as has been discussed here previously, the little gray Honeywell pressuretrols are nowhere near exact in their control of the steam pressure, they are more like ballpark guesstimates. After you insulate your pipes and install main vents, you might want to think about getting a good low pressure gauge (as Rod always suggests - from Gaugestore.com http://bit.ly/zV7O4V ) and seeing how inaccurate your pressuretrol really is. Then I would suggest you really think about replacing it with a vaporstat. You might cringe at first at the price, but you'll easily recoup that over the course of a heating season compared to what I'm sure you'll see as wasteful over-pressure of your current setup. Just my two cents, best of luck with your system fixes.

paserafi

Pics are old, prior to insulation

J.A., yeah those are old pics. The vaporstat upgrade was discussed with the plumber, and he mentioned it's pricey. I'll do my own research on it, as I know for sure I'll recoup SOME savings, if anything at least the cost of the part, like you said. Last night was in the teens outside so naturally my boiler ran quite a bit. I noticed at one point my thermostat read 65 but the rooms around it all felt warmer. I touched the thermostat to open the lid and it jumped to 67 (not a good sign). Then i ran downstairs and waited as the boiler continued to run for another 5 minutes until reaching 3.5psi (on the internal chamber guage) and then it cut out. So I'm thinking step 1 of my plan above needs to happen in the next day or two...new thermostat. Since my pressuretrol is set to cut out at 1.5psi, then it's either way crappier than you said it probably is, or the pressure guage is inaccurate/not calibrated.

Any thoughts still on the location of the main vent? Think it will be effective and proper at the top of the riser? I can get over the look of it in my living room if it means quieter, more efficient heat cycles.

BobC

Gorton #2

Mounting it on the riser in your livingroom would work as long as you and your plumber can come up with an easy way to do it, do yourself a favor and don't do anything that will make you have to remove the spud from the radiator. That is not easy and can incur unexpected additional expense.



You could also mount it off one of the 90's in the basement by replacing the 90 with a T but by the time you add another 90 to the T and a reducer to get down to the 1/2" I'm not sure you would have room for that Gorton #2. You could just pipe it over to an open joist bay but make sure there is some slope so any water finds it's way back to the boiler. Again the Gorton #1's would fit but then your left with an expensive paperweight on your hands.



With the addition of a main vent the radiator vent will only be handling the radiator and not the whole system so it could be fairly low capacity vent.



The pressuretrol may be off but I'd suspect that 0-30 gauge first.



Bob

paserafi

Gentle with those spuds

Thanks BobC. You're right, it would be a very tight squeeze fitting that Gorton #2. Piping over to another joist bay is a good idea. The cheaper option of installing it at the radiator is certainly more risky. I removed one spud in another room to replace a broken shut off valve that I could not fix, and it was a 3-hr project involving a sawzall and chisel. The little rounded corroded nubs in the the old spud sheared right off with very little force turning the spud wrench. Desperate, I found this link possibly somewhere on heatinghelp: http://bungalow23.com/2006/09/27/replacing-a-radiator-valve/  - down in the comments by Robert, the sawzall method is detailed. It worked, in case anyone runs into this problem. I slightly cut into the radiator threads (yikes!) but used thread sealant on the new spud and it never leaks. Cast iron is soft enough, I would recommend sawing by hand with a ridig metal cutting blade (pull saw would work i think, if the blade is for metal).



As I'm typing, the radiators are hissing away after I cranked the heat up since it's 20 degrees outside. The cycle went as normal, minor clanging, some hissing. Then all around the same time all the vents started sucking air back in, whistling as they work. So I'm feeling good about the main vent solving my problem. But then, the vents started gurgling and getting very loud. They were blowing back out again, even though the thermostat was reading set temp. The boiler had cut on again, and was making new steam and pushing it back up again. The gauge was reading "0 psi". Could this be the crappy/faulty thermostat, or could it be something bad in the switch electronics on the radiator itself? I switched the TS to OFF and the boiler cut out, so I'm thinking it's gotta be this stinkin honeywell TS.