Main vents

alboguy

Hello all. This is my first post on this forum. I curently own a 1952 ranch 1400 sq. It has original steam heat. 2 weeks ago we replaced the furnace. I also replaced all the vents in the radiators with maid o mist vents. Nr 4 in the living room where the thermostat is located. Nr 5 in the warmer room and n6 in the 2 coldest rooms. The radiators heat up nicely. The last ones to heat up ar the ones in the living room, why?. Also replaced the main vents with gorton nr1. Should i pit more venting or is this enough. Now my real question is about the boiler, i lt shuts itself off every 3 min when is pruducin steam and the wayer on the glass moves violently up and down. Why.

KC_Jones

Most likely not enough venting on main. The rule of thumb is a Gorton#2 for every 20' of 2" (2 3/8" OD) pipe. A Gorton #2 is roughly 3 times the capacity of that #1 vent. As far as the bouncing it's because the boiler needs skimmed. I am guessing this wasn't done because the skim port wasn't installed. Funny they took out the knockout for it, but then didn't install it. You need to skim to get the oils out.

Mark N

You have a bullheaded tee in the supply piping. Each main should have its own take off from the header. Have the skim port installed and skim the boiler. Insulate any part of the mains that is missing insulation. Add more main venting as per KC's advise.

Fred

It looks like they did a nice job of piping your new boiler but they did fail to put in a skim Port. Not much work to put it in but you need to ask them to come back out and install one and skim it and show you how to skim it. Any new boiler and any new piping will have oils in the interior surfaces that wash down into the boiler water and float on the surface making it difficult for the steam bubbles to break through the surface to burst and create the steam you want. You may have to skim it multiple times until the water in the sight glass stabilizes. It should not bounce more than 1/2" to 3/4" when the boiler is running. The boiler is probably shutting down on low water as the water is probably being pushed out into the system due to the oils. Hopefully they measured your radiators and sized the boiler to the total Radiator EDR so as to prevent the boiler from short cycling on pressure. Make sure your Pressuretrol (gray box mounted on the looped pipe, pigtal) is set for a Cut-in Pressure of .5 PSI (scale on the front, adjusted by screw on top) and the Cut-Out is set to "1" (take cover off of Pressuretrol and you will see a white wheel inside numbered from 1 - 5) .
As far a your living room radiator, it probably takes longer because you are using a smaller vent (a number 4) while the other rads are venting faster. I wouldn't mess with trying to balance the venting until the boiler has been skimmed as that can have a significant effect on how the system heats. Once you get the water, in the boiler, stabilized, try adjusting you radiator vents down a bit. Vent the Mains fast by making sure you have enought vents on the mains and try to vent the rads reasonably slow so that steam gets to each rad at about the same time and so that the rads heat reasonably evenly. Remember, in mild weather the rads may not heat all the way across before the thermostat is satisfied. That is normal.

alboguy

How should i vent the mains faster, install more vents on both main pipes. Iam new to this make it like a loop, iam not sure,haw many vents do i need? Thanks for the answers

Fred

If you look at your 3rd picture, you have a Gorton #1 vent there. What you need to do is measure your main(s) For every 20 ft. of 2" Main, you should have a Gorton #2 (which is 3.5 times faster than a Gorton #1 at venting). If you need more that one Gorton #2 (based on the length of the Main(s), just buy a Tee and a couple elbows and add them there where that Gorton #1 is.
As was noted by @markn , you do have a bull headed Tee (where your riser connects to the headers, going in opposite directions. That shouldn't be there. That should be two mains, each individually tied into the header. It should be changed. In any case, for venting, you should treat each direction as a seperate Main and vent each end of each direction. That's the way it needs to be when you get that piping corrected and in the interim, adequate venting on both ends will help ensure one side doesn't steal all the steam because air can't escape from the other end.

gerry gill

New boiler needs its water cleaned. And for the other question, the #4 vent is small, so it will expel air slowly and allow steam in slowly.

alboguy

So thw piping in the right side needs to be changed, i measured the main and is 54 feel long.

Fred

alboguy said:

So thw piping in the right side needs to be changed, i measured the main and is 54 feel long.

I would put a minimum of 2 Gorton #2's on that main, 3 would be closer to ideal.
At the very top of your riser to the main(s) it looks like there is a Tee on top of the riser and a main that takes off in different directions. That's what needs to be changed. Each of those mains should drop to the header. It can be either the left or right main that is taken off of that Tee and dropped down to the Header.

alboguy

My plumer is coming tomorrow to put the skim port in, ill tell to chage the piping to. Ill keep you posted

Fred

Keep us posted!

alboguy

Hegot the boiler skimed, big difference, no more bouncing, boiler works better. I asked him about the pipe, he said its fine, nothing needs to be changed. Friday ill put the valves in.

Fred

Of course he'd say that. It's not right. It may work, somewhat, but it is not going to give you optimum steam flow. It is so much easier to fix it now than wait a couple years when the steam has pretty much welded those fittings together and you can't get a good balance between the radiators on those two mains.

alboguy

How does it look? Should they hiss when the mains get hot. I mesured the mains again and the were 38 feet, 34 feet, is this enough venting?

Fred

You should be good! It would have been nice if you could have elbowed up on the antler that has the Gorton #2 and the two Gorton 1's and then horizontally just so you could get a little better drainage and keep any dirt from blowing into those vents.

alboguy

Thanks, should they hiss when they vent air?

Fred

You will hear air blowing out of them but they should close and be silent when the steam hits them and closes them.

nicholas bonham-carter

Noisy vents are a sign of over pressure,or under venting, so check your system, with an installed 0-3 psi gauge.--NBC

alboguy

Radiators in the living room are the last to get warm, they have a nr 4 on them. They are not as hot as all the other ones. One thing i noticed after a changed the main vents, the system is so quiet. Shouls i put different vents in the living room, the radiators are pretty big, actually they are convectors.

BobC

Are those radiators at the end of the main?

If the piping has a sag or is not sloped it can collect water and that will collapse steam so it does not get to the radiator as fast as it should. Check the pipe that connects those rads to the main to be sure it has some pitch back to the main, also check to make sure that convector can drain back to the main also.

If all the slopes look good you try using a #5 vent to see if that speeds things up.

Bob

Fred

If the thermostat is in the living room, you don't want those convectors to heat too fast or they may satisfy the thermostat before the other rooms are up to temp.

alboguy

Ok, checked the pitch and its perfect, no sagging. So leave the nr4 vent or put a nr5

Fred

This is a situation where you can try a #5 but probably might do better by slowing some of the other radiators down a bit. They are possibly robbing the living room rads of some steam. Try the #5's and see if it affects other rads.

alboguy

They definitly heat up faster in the living room with a nr5. All the other heat up pretty much the same on all the other rooms, but not all the way, the bottom part is not hot like thw upper part.

Fred

Usually when a radiator heats either across the top or the bottom, that's a good indication that you have that radiator vented too fast and the steam is short circuiting the radiator by running across the top or bottom to the vent and closing that vent before the radiator can evenly heat. When we typically talk about a radiator not heating all the way across, we mean from side to side (but the tubes that heat, heat evenly top and bottom)and that is typical in mild weather and the thermostat is satisfied before the rad heats all the way across.
Try slowing one of those rads down with a smaller vent and see if it heats more evenly.

alboguy

All 4 do that except the convectors, i havr nr 5 on 4 radiators, 2 are small and 2 are pretty big

Fred

Venting those Rads too fast. They will heat across the Top OR the bottom but not likely to fully heat from top to bottom. The Vents re closing too fast to let all the air out.

alboguy

Damn no luck, should i try the hoffman vents? Spend a little bit extra and get a better valve.

Fred

I use the Hoffman 1A's. They are adjustable so you don't have to switch them out and they are reliable. Some people say they click but I haven' had that issue, except for one that has silenced after a couple months.

alboguy

At what setting did you set them near the thermostat, i ordered 2 today, iam leaving the mom on the other ones as they are working nice