No pressure, no leaks, plenty of air vents!
After several old steam boiler men have looked Ive taken in almost all conisderations, read all Dans books, countless hours online, still No pressure, not an ounce. The home heats very well, all radiators heat quickly, evenly, without noise. I have NO water hammer, all rads are pitched in this one pipe system.
My last project for this issue was to install 2" ball valves for each zone approx 6 feet away from the headers, this isolated each branch, success I thought, I was able to build pressure and watched the vaporstat do its thing. Ive got it narrowed to one zone (3 rads on this line). Heres what happens when I have all zones open except for the one in question, I open the ball valve which is also located near a 3/4 main vent from the wet leg approx 8 inches away and at the same height, i hear a whoosh and the boiler loses all its pressure....The whoosh appears to come from the 3/4 air vent, NO Leaks, no steam loss from the vents, No spitting, NADA, dry and quiet. So I then proceed to each of the 3 rads on the zone, all heated and fitted with new properly sized air vents. On one occasion with turning some of the vents upside down i get pressure, happened once, I was elated that it was a 20 dollar part. NO Luck, it was an abberation from a divine intervention that said to let this young man sleep soundly one night thinking he'd found the issue and it was a vent. My wife was elated that this was behind me, but me being so particular about mechanics and plumbing I kept checking the next day....Again back to square one. No pressure, not an ounce. Boiler runs and runs, Nest generates a history so I can see my run times by the day.
I know the boiler makes great pressure and steam with that zone closed, because Ive removed a 3/4" main vent on the opposite side of the basement and left it wide open, the steam pushes through with fervor, even with it open 3/4" ! Why aren't i seeing it or hearing something if I have a leak? Where is this pressure going ? Radiators all quiet and hot. Im at a loss, i will respond to any suggestions.
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Steam heating systems aren't supposed to make pressure -- or, more accurately, only just enough pressure to get the steam to the radiators, which may be only an ounce or two. As I read your description, a brief synopsis reads -- thermostat turns the boiler on, boiler runs, house warms up, thermostat turns off, boiler turns off. Which is exactly what's supposed to happen. What's not to like? The fact that it may run 18 hours in a day simply suggests that the heating system capacity is close to what is required in this miserable weather -- and that's a good thing, too.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
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The only ways a steam boiler stops firing is when the stat has reaches temp or the pressure reaches the preset limits, in my case 8 ounces. Steam heats the rads and then gives that heat slowly to the house. I’m not getting the power of the rads to do their job! The system should build to 8oz long before the house stat is satisfied and then let the rads heat the home. Otherwise boiler runs and runs. It never lets the heated rads do their thing.0
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Ah... no. The question is, are the radiators hot? Not does the pressure build. For example, in the main place I care for, the pressure does rise when the boiler fires off -- to 2 ounces. And sits there until all the radiators are hot. Since Cedric is slightly oversized, it then cycles off on pressure (6 ounces) until the radiation can catch up. That takes about an hour.
Now if the problem is that the pressure never rises and the radiators are not hot, that's different story -- and would suggest a leak, except that you say you are not using water.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England1 -
Jamie, I ask you this, why does my boiler build pressure almost instantly the moment I close the 2" ball valve to the zone in question? The boiler operates within spec on every isolation combination except when i incorporate that zone0
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Some of the discussions on this site ...unfortunately...have perpetuated the story unintentionally that a steam boiler "must build pressure"
Most of us know this is not true. Many install vapor stats and low pressure gages and then find out they are not needed, the boiler doesn't build pressure......so the homeowner thinks their is something wrong....so it seems like money spent for nothing.
If you are really concerned you could have the firing rate of the boiler checked and check the EDR of the boiler nameplate versus the EDR of all the radiation.
Seems like your fine to me0 -
A boiler does not make pressure, I think you have some misconceptions about how this works. The system will build pressure with resistance. If the boiler wasn’t connected to anything it would produce steam which would pour out until the water was gone, there would be no pressure.
Hook a properly sized boiler up to a heating system and the resistance of the system will dictate the pressure. When things are sized properly you shouldn’t get much if any pressure.
When you close a ball valve on one branch you reduce the system size which increases the resistance so you get more pressure. Open the valve and you change that, pressure drops and back to normal.
Pressure in a steam system is bad, and not needed for operation. Also building pressure actually slows down the heating, to build pressure the steam has to stop moving, you ball valve shows this perfectly.0 -
KC Jones. Considering my home was built by Ernest Flagg, a widely known architect from the 20th Century- built for his daughter no less, Im going to think his boiler crew at the time were closely scrutinized and likely the top men in that space at the time. So, the pipe work likely spot on, the boiler likely sized perfectly. Im still curious about this whoosh I ONLY hear when i close and open the ball valve for this particular zone. All other ball valve opening/closing lead to no whoosh at the main vents...0
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This is a bit of a guess -- but if the boiler does build some pressure with the three other zones open, but not that one, I'd have to wonder a bit at the main vents on the other zones. Not that I think you have a problem -- if the house heats evenly, I'd not worry about it -- but I can understand the curiousity.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
The main criteria is, is your house heated comfortably? If so and if your boiler does that without building pressure, then you are in the best situation you could be. If you try to make your boiler build pressure when it doesn’t need to, you are just wasting fuel and money. It takes energy, which costs $’s, to build pressure. Be happy sounds like you have a perfectly set up heating system.0
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We need some pictures of the boiler, the piping around the boiler and some of the vents. Especially all of the main vents.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Gary Smith:
Im wasting fuel by satisfying the stat ONLY, the boiler won't stop running unless the stat tells it because i never get to 8 oz of pressure which would allow the rads to give their heat to the room without the stat satisfied. My situation is unique because i get great even heat, dry steam, no water loss etc....BUT I need a way to get the rads to their job before the stat tells the boiler enough...Gary Smith said:The main criteria is, is your house heated comfortably? If so and if your boiler does that without building pressure, then you are in the best situation you could be. If you try to make your boiler build pressure when it doesn’t need to, you are just wasting fuel and money. It takes energy, which costs $’s, to build pressure. Be happy sounds like you have a perfectly set up heating system.
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Jamie Hall said:
This is a bit of a guess -- but if the boiler does build some pressure with the three other zones open, but not that one, I'd have to wonder a bit at the main vents on the other zones. Not that I think you have a problem -- if the house heats evenly, I'd not worry about it -- but I can understand the curiousity.
Main Vents all brand new, properly installed on nipples about 4 inches over the main at the end of each line. House was built by the book, no plugs, no steam boiler repairmen allowed to touch any lines that would change original specs. Like I said earlier, with the zone at issue closed via the 2" ball valve, I can remove any of the other main vents and I see a full head of steam, so even if i had a leak somewhere, the boiler is able to make steam and pressure with a 3/4" hole! which by the way makes a racket, so if I had a similar issue in the problem zone, I'd see/smell/hear it. Its a small house, all pipes visible. Im having a physics issue, the steam is disappearing when introduced to the questioned zone and the boiler can't keep up...scratch my head, a lot.0 -
AnthonyV said:
Gary Smith:
Im wasting fuel by satisfying the stat ONLY, the boiler won't stop running unless the stat tells it because i never get to 8 oz of pressure which would allow the rads to give their heat to the room without the stat satisfied. My situation is unique because i get great even heat, dry steam, no water loss etc....BUT I need a way to get the rads to their job before the stat tells the boiler enough...Gary Smith said:The main criteria is, is your house heated comfortably? If so and if your boiler does that without building pressure, then you are in the best situation you could be. If you try to make your boiler build pressure when it doesn’t need to, you are just wasting fuel and money. It takes energy, which costs $’s, to build pressure. Be happy sounds like you have a perfectly set up heating system.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Look. The thermostat only knows one thing: is the temperature of the space where it is set, or isn't it? If the temperature of the space is below the set point, it will close and ask the boiler to produce steam to warm the space up. If it is at the set point, it will open and the boiler will stop.
Now you say "I get great even heat, dry steam, no water loss" and, eventually -- even with the rather chilly days we've had lately -- the thermostat evidently agrees: it does turn the boiler off.
Like @ChrisJ I'm baffled. Seems to me that your boiler is providing steam to the radiators when it's asked for it. The radiators are providing even heat, and enough of it, when asked.
The boiler is doing its job properly. The radiators are doing their job properly. Ah... what's the problem?Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
> @AnthonyV said:
> Gary Smith: The main criteria is, is your house heated comfortably? If so and if your boiler does that without building pressure, then you are in the best situation you could be. If you try to make your boiler build pressure when it doesn’t need to, you are just wasting fuel and money. It takes energy, which costs $’s, to build pressure. Be happy sounds like you have a perfectly set up heating system.
>
> Im wasting fuel by satisfying the stat ONLY, the boiler won't stop running unless the stat tells it because i never get to 8 oz of pressure which would allow the rads to give their heat to the room without the stat satisfied. My situation is unique because i get great even heat, dry steam, no water loss etc....BUT I need a way to get the rads to their job before the stat tells the boiler enough...
Why do you think your rads aren't working until your system builds pressure? The water expands when it heats to steam, then heads out to your rads. When it hits the rads, that steam condenses, which takes up less space than the steam and gives off its heat. This is the balance that all installs should aim for. Stopping on pressure means there was more steam available than neededYou can have it good, fast or cheap. Pick two0 -
@Canucker , ideally I'd expect the rads to give their heat while the boiler is off, the issue is the boiler runs 17+ hours a day, its a small house. As a means to achieve some efficiency, the most basic of efficiency, the boiler should get a few ounces of steam, cycle off and let rads continue to give their heat to the home. Thats not whats happening, The boiler runs 17 hours because the stat is the only off mechanism, its located in the largest room that happens to have 2 rads on opposite side, so its allows the house to heat nicely.0
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17+ hours of run time? everyday. No water loss, no visible leaks, vented better than any system I've ever see in a residential setting. No water hammer, no steam going out the Flue, all boiler controls function as spec'd, new pigtails to the vaporstat and the gauge. 2k sq ft stone home, as pictured in my image. the name of the house is BOWCOT, yes it has a name and a load of stuff on-line. So, I guess I'm looking to understand why I can't this sucker to cycle off other than the stat. I want to force 6-8oz of pressure so the rad can satisfy the stat instead of the Boiler burning fuel.Jamie Hall said:Look. The thermostat only knows one thing: is the temperature of the space where it is set, or isn't it? If the temperature of the space is below the set point, it will close and ask the boiler to produce steam to warm the space up. If it is at the set point, it will open and the boiler will stop.
Now you say "I get great even heat, dry steam, no water loss" and, eventually -- even with the rather chilly days we've had lately -- the thermostat evidently agrees: it does turn the boiler off.
Like @ChrisJ I'm baffled. Seems to me that your boiler is providing steam to the radiators when it's asked for it. The radiators are providing even heat, and enough of it, when asked.
The boiler is doing its job properly. The radiators are doing their job properly. Ah... what's the problem?0 -
Ah. Perhaps I see part of the difficulty here. The radiators only give off significant heat while they are being supplied with steam. They do store a little heat in the iron -- you can feel this once the boiler shuts off as they cool down -- but the heat which the radiators produce is only because they are being fed with steam. In most systems it will take less than a minute for the steam out in the system to condense once the boiler shuts off -- and then you get little more heat (the thermostat compensates for that by shutting the boiler off slightly early).
Bottom line: the radiators will only give heat if they are fed steam. Period. Which means the boiler has to be running.Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Does the system always run for 18+hrs or has it only been during the recent cold snap? I wish I could be there to see the system and show you how, from the information you've provided, you have what sounds like an almost perfectly sized and installed steam system. Very rare in this day and age. You are one of the few we've heard of around here to have a system, that I'm willing to bet, is extremely comfortable to live with because there are no overheating incidents due to shutting down on pressure or banging pipesYou can have it good, fast or cheap. Pick two0
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What is the thermostat set to @AnthonyV? Are you using set backs?0
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Respectfully disagree that 'radiators only give heat while being fed steam'...This defeats the whole purpose of the radiator, the cast iron absorbs the heat from the steam then give off their latent heat. This was one of the designing principles behind the industrial revolution.Jamie Hall said:Ah. Perhaps I see part of the difficulty here. The radiators only give off significant heat while they are being supplied with steam. They do store a little heat in the iron -- you can feel this once the boiler shuts off as they cool down -- but the heat which the radiators produce is only because they are being fed with steam. In most systems it will take less than a minute for the steam out in the system to condense once the boiler shuts off -- and then you get little more heat (the thermostat compensates for that by shutting the boiler off slightly early).
Bottom line: the radiators will only give heat if they are fed steam. Period. Which means the boiler has to be running.0 -
Danny Scully said:
What is the thermostat set to @AnthonyV? Are you using set backs?
its a Nest thermostat set to different temps for our schedule, so even more the point that Im conserving burn time to an algorithmic solution set by engineers. the Nest also offers a setting for steam heat so it knows the delays in heat up time and understands the cool down cycle.0 -
See now we’re getting somewhere @AnthonyV. Technology can be a wonderful thing but in this case, the simpler the better. Get rid of the schedule and any kind of other “algorithmic solution set by engineers”...Set it to ONE consistent temperature, that’s it. No set backs no nothing. Leave it alone and get back to us.1
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The temp modulation is but a few degrees for each 6 hour slot in the day, it drops when house is empty by 2-3 degrees, then heats up when house is occupied. the algo only drives the scheduling. As it stands, by keeping the house at that warm temp all day would cause the boiler to NEVER go off. Worsening my dilemmaDanny Scully said:See now we’re getting somewhere @AnthonyV. Technology can be a wonderful thing but in this case, the simpler the better. Get rid of the schedule and any kind of other “algorithmic solution set by engineers”...Set it to ONE consistent temperature, that’s it. No set backs no nothing. Leave it alone and get back to us.
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You came here for advice from professionals. I’m a professional. I deal with this everyday. I’m telling you that nest is part of the problem. Best of luck.2
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You're in NYC?
It's been very cold. It's not unreasonable for a boiler to run 18 hours per day in such weather.
A properly sized one would have run 24 hours during these conditions or close to it.
The Nest is garbage.Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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Stick to banking. You've got the engineering wrong almost completely. Also ditch the Nest.AnthonyV said:
Respectfully disagree that 'radiators only give heat while being fed steam'...This defeats the whole purpose of the radiator, the cast iron absorbs the heat from the steam then give off their latent heat. This was one of the designing principles behind the industrial revolution.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England2 -
Anthony,
It seems that your boiler is well matched to the amount of attached radiation. I have the same situation. My boiler is rated at 271sqft of EDR and my radiators add up to 265sqft of EDR. When my boiler is running observed pressure is below 1oz. The heating cycle is completely controlled by the thermostat. Steam moves on the pressure differential between the boiler and the air vents. High pressure goes to low pressure even if the difference is a fraction of an ounce. By closing off your mains you causing your boiler to be oversized. This will cause the pressure to rise. The boiler is making more steam than your radiators can condense. I myself don't use any setback, but that is a personal choice. How long does the boiler run on a call for heat? Should be around approx. 20 minutes. How long is it off between calls for heat? What is your setpoint? What is the setback you're using? I'm not familiar with the Nest thermostat as I've never used one. I use a Honeywell FocusPro 5000 set to 1cph. This gives very satisfactory results. This Tstat doesn't track total daily run time so I don't know what it is.0 -
Why is my understanding of the engineering wrong? Latent heat?Jamie Hall said:
Stick to banking. You've got the engineering wrong almost completely. Also ditch the Nest.AnthonyV said:
Respectfully disagree that 'radiators only give heat while being fed steam'...This defeats the whole purpose of the radiator, the cast iron absorbs the heat from the steam then give off their latent heat. This was one of the designing principles behind the industrial revolution.
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Mark N said:
Anthony,
It seems that your boiler is well matched to the amount of attached radiation. I have the same situation. My boiler is rated at 271sqft of EDR and my radiators add up to 265sqft of EDR. When my boiler is running observed pressure is below 1oz. The heating cycle is completely controlled by the thermostat. Steam moves on the pressure differential between the boiler and the air vents. High pressure goes to low pressure even if the difference is a fraction of an ounce. By closing off your mains you causing your boiler to be oversized. This will cause the pressure to rise. The boiler is making more steam than your radiators can condense. I myself don't use any setback, but that is a personal choice. How long does the boiler run on a call for heat? Should be around approx. 20 minutes. How long is it off between calls for heat? What is your setpoint? What is the setback you're using? I'm not familiar with the Nest thermostat as I've never used one. I use a Honeywell FocusPro 5000 set to 1cph. This gives very satisfactory results. This Tstat doesn't track total daily run time so I don't know what it is.
I would say the boiler runs for nearly 1 hour before the stat is satisfied, then re-fires in 20 mins or so. Vaporstat is set for 8 oz with a subtractive diff of about 4 oz. It never triggers as the boiler never gets to even register 1 oz. Im unsure why the NEST has anything to do with the cycling temp, it merely allows a scale on a longer term outlook that helps with short cycling and processing latent heat the radiators give off etc... The older guys seem to shun the technology yet the data says otherwise. How else could you keep track of efficiency? how can you attempt to improve efficiency without the data? all fair questions.0 -
I’m 33 @AnthonyV
If you don’t want to listen that’s fine, when you figure it out let us know what it was. 
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AnthonyV said:Mark N said:
Anthony,
It seems that your boiler is well matched to the amount of attached radiation. I have the same situation. My boiler is rated at 271sqft of EDR and my radiators add up to 265sqft of EDR. When my boiler is running observed pressure is below 1oz. The heating cycle is completely controlled by the thermostat. Steam moves on the pressure differential between the boiler and the air vents. High pressure goes to low pressure even if the difference is a fraction of an ounce. By closing off your mains you causing your boiler to be oversized. This will cause the pressure to rise. The boiler is making more steam than your radiators can condense. I myself don't use any setback, but that is a personal choice. How long does the boiler run on a call for heat? Should be around approx. 20 minutes. How long is it off between calls for heat? What is your setpoint? What is the setback you're using? I'm not familiar with the Nest thermostat as I've never used one. I use a Honeywell FocusPro 5000 set to 1cph. This gives very satisfactory results. This Tstat doesn't track total daily run time so I don't know what it is.
I would say the boiler runs for nearly 1 hour before the stat is satisfied, then re-fires in 20 mins or so. Vaporstat is set for 8 oz with a subtractive diff of about 4 oz. It never triggers as the boiler never gets to even register 1 oz. Im unsure why the NEST has anything to do with the cycling temp, it merely allows a scale on a longer term outlook that helps with short cycling and processing latent heat the radiators give off etc... The older guys seem to shun the technology yet the data says otherwise. How else could you keep track of efficiency? how can you attempt to improve efficiency without the data? all fair questions.
I use an outdoor reset with my steam boiler that calculates run times based on outdoor temperature and the heatloss of my house.
My thermostat is a Honeywell Prestige with multiple indoor sensors.
I shun the Nest, not technology.
Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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The thermostat is literally what controls the system and as far as that goes, it's doing it's job.
For some reason you think otherwise and we're all baffled by this.Single pipe 392sqft system with an EG-40 rated for 325sqft and it's silent and balanced at all times.
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> @AnthonyV said:
> Respectfully disagree that 'radiators only give heat while being fed steam'...This defeats the whole purpose of the radiator, the cast iron absorbs the heat from the steam then give off their latent heat. This was one of the designing principles behind the industrial revolution.
>
> Stick to banking. You've got the engineering wrong almost completely. Also ditch the Nest.
>
>
>
> Why is my understanding of the engineering wrong? Latent heat?
The latent heat is given up the instant the steam condenses, which happens roughly speaking within a few seconds of it entering the radiator. Once the boiler cuts out the radiator is constantly cooling. Will you get some heating after boiler shut down? Yes, but it's minimal. I have a system on mine that reads in 1/100th of a degree and I can stand there and watch the temp in the room rise after boiler shut down and then begin to fall again. This all happens within minutes and the rise might be 1 tenths of a degree and then it will start dropping. This of course depends on the outdoor temperature, but with the weather we have been having I get zero rise in temp after burner shut down.
The performance you see would be considered normal, actually I would suggest above average.
If you never ever hit the cutout pressure that is the desired performance, I really haven't a clue what you feel the pressure is doing for you? Remember as soon as the burner cuts out the steam collapses, I know in my system on the rare occasion I have hit my 8 ounce cut out (basically forcing it) the burner shuts down the pressure drops to zero in less than 30 seconds.
With no burner you get no heating, at least not at the level you are thinking.
When it gets cold like we saw recently, my boiler runs as much if not more than you are stating.
There is no free lunch, and you are incessantly looking for one that does't exist.0 -
Listen to what?Danny Scully said:I’m 33 @AnthonyV
If you don’t want to listen that’s fine, when you figure it out let us know what it was.
I guess everyone has their own preference as far as stats go. But the Nest receives its info via the web, thereby doing the same job as the outdoor reset, down to wind, humidity, temp etc...and its able to process the data so that outside temp isn't the only input in deciding run time. Im partial to the newer technology I suppose. But Thank you for the help, it is appreciated.ChrisJ said:AnthonyV said:Mark N said:Anthony,
It seems that your boiler is well matched to the amount of attached radiation. I have the same situation. My boiler is rated at 271sqft of EDR and my radiators add up to 265sqft of EDR. When my boiler is running observed pressure is below 1oz. The heating cycle is completely controlled by the thermostat. Steam moves on the pressure differential between the boiler and the air vents. High pressure goes to low pressure even if the difference is a fraction of an ounce. By closing off your mains you causing your boiler to be oversized. This will cause the pressure to rise. The boiler is making more steam than your radiators can condense. I myself don't use any setback, but that is a personal choice. How long does the boiler run on a call for heat? Should be around approx. 20 minutes. How long is it off between calls for heat? What is your setpoint? What is the setback you're using? I'm not familiar with the Nest thermostat as I've never used one. I use a Honeywell FocusPro 5000 set to 1cph. This gives very satisfactory results. This Tstat doesn't track total daily run time so I don't know what it is.
I would say the boiler runs for nearly 1 hour before the stat is satisfied, then re-fires in 20 mins or so. Vaporstat is set for 8 oz with a subtractive diff of about 4 oz. It never triggers as the boiler never gets to even register 1 oz. Im unsure why the NEST has anything to do with the cycling temp, it merely allows a scale on a longer term outlook that helps with short cycling and processing latent heat the radiators give off etc... The older guys seem to shun the technology yet the data says otherwise. How else could you keep track of efficiency? how can you attempt to improve efficiency without the data? all fair questions.
I use an outdoor reset with my steam boiler that calculates run times based on outdoor temperature and the heatloss of my house.
My thermostat is a Honeywell Prestige with multiple indoor sensors.
I shun the Nest, not technology.0 -
@AnthonyV
You haven't answered any questions I posted about the EDR capacity of the boiler or the EDR capacity of your radiation or if the firing rate of your boiler or combustion efficiency has been checked.
Without that information no one can help you.
Want pressure?
Install a valve in the steam supply pipe coming off the boiler. Throttle it until you get the pressure on the boiler that you want. Watch your expensive vaporstat cycle the burner, watch your new pressure gage build pressure. Enjoy!
Then you can enjoy the increased price of fuel needed.
The lower the pressure generated to heat the building the lower the fuel consumption
Until we know weather your boiler is undersized or not no one can tell what is happening. Your boiler could be under fired...Combustion test1 -
@AnthonyV , We all wish our boilers were sized so closely to the connected radiation that we don't build anymore pressure than what is needed to get steam to all the radiators. The reason you build pressure when you close that third main (or as you term it "Zone") is because when you take any number of radiators off line, you reduce the connected radiation or EDR, reducing the number of radiators that can condense the steam. That causes the boiler to produce more steam than the remaining radiators can condense, hence you build pressure. That's not any sign of success. The goal, as everyone has said is to allow the boiler to provide enough steam to heat each room and satisfy the set temp of the thermostat. Remember, when you isolate a main, yes, you build pressure but you are not warming those rooms that are served by that main. That is not what efficiency or comfort is about.
The swoosh you hear, when you open that isolation valve, because you have allowed the system to build pressure with less connected radiation, is all the air in that closed main is now pushed out through the vent very quickly. When steam hits that vent, it then closes. After that, there is no longer any noticeable pressure in the system because you have now returned the full condensing capacity of the system that matches the output of your boiler.
What everyone here has said, in their posts is correct. Enjoy that you have your system perfectly sized and tuned and leave all those mains (or zones) open, except perhaps for the rare occasions when you want to build some pressure at the boiler to blow sediment/crap out of the boiler. At those times you want to temporarily close all the mains. If you want to save fuel costs, lower the set point on the thermostat.0 -
I will have to get back to you about the EDR calculations. I did have the efficiency test done, came in at about 75%. Im not sure if that test encompasses the combustion, but all levels were within range when the efficiency test was performed. Mind you, the system is a texaco Fuel chief, converted to gas from oil in the 1970's according to paperwork found. Boiler was estimated to be from the 1950's according to one gentleman. I was quite surprised to see 75% efficiency for that old girl.EBEBRATT-Ed said:@AnthonyV
You haven't answered any questions I posted about the EDR capacity of the boiler or the EDR capacity of your radiation or if the firing rate of your boiler or combustion efficiency has been checked.
Without that information no one can help you.
Want pressure?
Install a valve in the steam supply pipe coming off the boiler. Throttle it until you get the pressure on the boiler that you want. Watch your expensive vaporstat cycle the burner, watch your new pressure gage build pressure. Enjoy!
Then you can enjoy the increased price of fuel needed.
The lower the pressure generated to heat the building the lower the fuel consumption
Until we know weather your boiler is undersized or not no one can tell what is happening. Your boiler could be under fired...Combustion test0 -
Well said, Thank you for that insight, The whoosh is what was driving me to heck, I agree with the physics 100%, but heres why I still think an issue is at hand. Th whoosh is only heard one 1 of the 3. The other 2" ball valves don't create that whoosh out of the main vents when I release the pressure back to those mains. Why only the one main thats causing the pressure to goto zero? There isn't any possibility that the the small rad vents are letting all that pressure/air escape without me hearing...Fred said:@AnthonyV , We all wish our boilers were sized so closely to the connected radiation that we don't build anymore pressure than what is needed to get steam to all the radiators. The reason you build pressure when you close that third main (or as you term it "Zone") is because when you take any number of radiators off line, you reduce the connected radiation or EDR, reducing the number of radiators that can condense the steam. That causes the boiler to produce more steam than the remaining radiators can condense, hence you build pressure. That's not any sign of success. The goal, as everyone has said is to allow the boiler to provide enough steam to heat each room and satisfy the set temp of the thermostat. Remember, when you isolate a main, yes, you build pressure but you are not warming those rooms that are served by that main. That is not what efficiency or comfort is about.
The swoosh you hear, when you open that isolation valve, because you have allowed the system to build pressure with less connected radiation, is all the air in that closed main is now pushed out through the vent very quickly. When steam hits that vent, it then closes. After that, there is no longer any noticeable pressure in the system because you have now returned the full condensing capacity of the system that matches the output of your boiler.
What everyone here has said, in their posts is correct. Enjoy that you have your system perfectly sized and tuned and leave all those mains (or zones) open, except perhaps for the rare occasions when you want to build some pressure at the boiler to blow sediment/crap out of the boiler. At those times you want to temporarily close all the mains. If you want to save fuel costs, lower the set point on the thermostat.0 -
@AnthonyV , there are any number of factors that can make a difference between those mains:
- The difference in length and diameter of the mains. Longer and or bigger mains have more air in them.
- The size and/or number of vents you have on each main.
- The amount of time you let the boiler build pressure before you open any of the isolation valves.
- The actual pressure in the system at the time you open anyone of those valves
- The number of radiators connected to each main. The more radiators, the more vents to dissipate the air.
- The size of the radiators connected to each main. Bigger radiators can act as a larger "buffer" to the impact of sudden exposure to pressure.
- The size of the radiator run-outs on each main.
- The list just goes on and on.
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