System Balancing Question

JohnW2

I'm having trouble getting my one pipe steam system balanced the way I want it. The main problem is that the house was built with a huge radiator in the master bedroom, and it gets like an inferno in there. You have to turn the thermostat way down at night or open a window to be able to sleep. I can easily solve the problem by turning the air vent on that radiator down to 1. The problem is, when I do that, the rest of the system gets angry. I start getting whining from the air vents on the other radiators, and I get expansion and contraction noises on the other radiators that I don't get when the master bedroom one is turned up higher. It seems to be the case that the system needs the bedroom radiator to do its part in order for the whole system to run properly. The air vents are all knew, and I have a new Gorton #2 main vent. I have the pressuretrol bottomed out at .5. Is what I'm describing typical, or should I be able to turn down the bedroom radiator without causing problems with the rest of the system? And, if this isn't typical, is there anything else I can try? Thanks for any help.

KC_Jones

Are you positive you have enough main vents? It sounds like the radiators are still trying to vent the mains. That would be one reason that turning down one vent would affect the other rads. If the main is fully vented before the rads start getting steam it shouldn't act like this. Have you timed the venting of your main to get a feel for what is going on in the system? Just a few ideas I am sure others will chime in with some ideas. A map of your system can help you and the people on this site help with diagnosis, length of mains what type of vents on the rads the size of the rads etc. I am sure some will ask for some pictures as well. The more you can post the better the responses will be.

BobC

Do you know what the steam pressure is? A 30 PSI GAUGE IS NOT AT ALL GOOD DOWN AT THE 1 TO 1.5 PSI YOU SHOULD BE RUNNING AT.

Do you know what the EDR (sq ft of radiator) of that one radiator is in relation to the rest of the radiators? What kind of vent is on that one radiator and what kind of vent is on all the others? In general you want to vent the mains very fast and the radiators slowly.

Are you sure the pressure is below 1.5PSI?

Bob

Fred

My guess is that the Pressuretrol is way out of adjustment or defective. You say you have it bottomed out at .5 psi. That is probably cut-in. There is a wheel inside that you adjust for cut -out (the pressure at which the burner will shut down) That wheel should be set at about 1 psi. Additionally, you need to sit there and watch the pressure gauge during a full steam cycle to see if the Pressuretrol is actually working.

KC_Jones

And as has been stated many times on this site get a proper low pressure gauge 0-3 PSI which will actually tell you something.

JohnW2

Thanks for the replies. The pressuretrol is set how Dan says to do it in his book. The cut-in is at .5 and the white dial is set to 1. The gauge is a 0-30 gauge, but I've never seen it move off of zero. I haven't measured the radiators so I can't give an exact number. The house is small, with eight radiators. I would say three are large, three are medium and two are small. This is one of the large ones. (I know that isn't much to go on; I need to measure.) The radiator valves are all Tunstall adjustable valves that can be set from 0-8. I have one Gorton #2 main vent. I can hear it working, so it is doing something. How can I tell if the Pressuretrol is defective? Also, KC, can you tell me what you mean by timing the venting of the main to get a feel for what is going on in the system? Thanks.

KC_Jones

You turn the system on and once the header at the boiler is hot STEAM HOT you start timing the steam and track how long it takes to reach the end of the main. You can compare that to how long the main is to see if you are venting enough. If you haven't done so I strongly suggest you buy
Balancing Steam Systems Using a Vent-Capacity Chart, by Gerry Gill and Steve Pajek from the store it will explain in greater detail what I am talking about. It helps take a ton of the guess work out of this. It's only 10 bucks and it goes to charity. There is a lot of information in there about venting and balancing the system. I don't have any Gorton #2 on my system, but I do have a couple #1 and I can tell you they are silent when working. If you are hearing them vent I would suspect they are being overworked. My old vents made hissing noises and were way undersized. Now that I have the proper size they are silent. Someone else can feel free to correct me if I am wrong there.

Fred

In my case, the 0-30 PSI gauge would say 5 PSI and I wouldn't believe it because the Pressuretrol was set at .05 and 1PSI. After seeing/hearing a good bit of hissing from the rad vents, I put a 0-3 PSI gauge on and the pressure was way high. There is a way to adjust the Honeywell 404 Pressuretrol and I was able to get it back in adjustment but I decided to put a Vaporstat on so that I could manage pressure in ounces rather than pounds. I kept the Pressuretrol as well to provide a backup should the vaporstat fail. Needless to say, the system has been much happier at the lower pressures. The only way to tell if the presuretrol is working is to turn the thermostat up 3 to 4 degrees above current room temp and sit by the boiler during a full steam cycle and watch the pressure gauge (this is where a 0-3 PSI gauge is much more reliable). If the pressure goes well over the 1.5 PSI range, the Pressuretrol is either out of adjustment or failed. Also, If you can measure the length of your mains and the diameter, we can tell you how much venting you need. That gorton #2 is a good start but still may not be enough. do you only have one main? Each main should be vented.

JohnW2

Thanks again for the replies. I will order the ebook. I only have one main; I will measure it tonight. I did think of a related question I have. Lately, I've been getting really obnoxious banging sound from a few of the radiators a few minutes after the system turns on. It's not water hammer; it's a single snap. As best as I can tell, these three radiators all have a pipe that is touching the edge of the wood floor and this is where the sound is coming from. However, we have lived in the house for 10 years, and these noises are recent. It would seem odd that after 10 years, all three radiator pipes settled against the edge of the floor at the same time, so my guess is that they've been like that for a while. Is it possible that too much pressure in the system would cause the steam to be hitting the radiators with more force, and this is why several of them started making these noises all at the same time?

Fred

Noise could be from almost anything. Does it just happen once at each radiator? It could be simple expansion of the pipe or radiator or it could bea pipe rubbing against the floor/joist. Excessive pressure can make strange things happen. Make sure the pressure is where it should be, check to make sure the radiators are pitched slightly back towards the steam inlet pipe/valve so that the condensate can drain back to the boiler and make sure all of your horizontal piping has some pitch as well.

JohnW2

OK, I measured my main. It's 55 feet in length. Unfortunately, I don't have pipe calipers, so I could only take a measurement by measuring around the outside. It looks like 35 feet of the pipe is 8 inches around the outside, and 20 feet are 11 inches around the outside.

BobC

You probably have 35 ft of 2" pipe and one Gorton #2 is probably not enough. The 20 ft is probably 3" pipe and that has a little more air in it than 35 ft of 2" pipe.

You need a MINIMUM of a gorton #2 and a Gorton #1 on each main and you would be better off with 2ea Gorton #2's on each main. Also put a low pressure gauge on the system to see what pressure you are running at, I suspect your 30 PSI gauge is broken.

On the noise front look around and see if there are any spots the pipe might be rubbing and put a piece of milk jug in there to see if it quiets things down. Also go over all the piping you can reach with a level, don't trust your eye.

Bob

Fred

OK, It looks like the inside diameter of the 35 ft section is 2 inch pipe and the inside diameter of the 20 ft section is 3 inch. Total volume of air to be expelled is 1.808 cubic feet. The Gorton #2 can expell 1.1 cubic feet per minute at 1 ounce of pressure and 1.750 cubic feet at 2 ounces of pressure. I would have 2 Gorton #2 s on that main.

JohnW2

OK, I'll look into having that done. Thanks for all your help!