Can you balance a system with no measurable pressure ever?

BobC

Have you confirmed the boiler is actually consuming as much gas as it's supposed to? If the pipe bringing gas into the house is full of crud (ask me how I know) the gas pressure will drop and you won't get proper gas pressure at that boiler.

The only way to be sure is to clock your gas gauge.

Bob

Jells

BobC said:

Have you confirmed the boiler is actually consuming as much gas as it's supposed to? If the pipe bringing gas into the house is full of crud (ask me how I know) the gas pressure will drop and you won't get proper gas pressure at that boiler. The only way to be sure is to clock your gas gauge. Bob

Thanks Bob, but I guess you didn't read all the commentary up thread about how I clocked and calculated the BTUs. Fair enough, this is gone on and on! 

I'm basically convinced it's a dirty boiler and burner. I didn't think it was possible to lose that many BTUs but it must be since it's the only answer that fits the facts.

ChrisJ

Jells said:

BobC said:

Have you confirmed the boiler is actually consuming as much gas as it's supposed to? If the pipe bringing gas into the house is full of crud (ask me how I know) the gas pressure will drop and you won't get proper gas pressure at that boiler.

The only way to be sure is to clock your gas gauge.

Bob

Thanks Bob, but I guess you didn't read all the commentary up thread about how I clocked and calculated the BTUs. Fair enough, this is gone on and on! 

I'm basically convinced it's a dirty boiler and burner. I didn't think it was possible to lose that many BTUs but it must be since it's the only answer that fits the facts.

You never told us what vents are on the radiators.
At that point, I gave up trying to help.

KC_Jones

I don't think you are giving enough weight to the venting situation. You aren't losing BTU's you just aren't getting them where you want. I can make rooms in my house colder, warmer, move things around with main vents, rad vents etc. My boiler is controlled by a PLC and fires exactly the same (based on weather conditions) all the time, the BTU's aren't lost, I'm just moving them to different locations.

We have tried to give you answers, you seem resistant to implement them, so I'm not sure what to tell you other than repeating what has been said.

You have a venting issue that needs to be resolved. What size vents are on all the rads? The total of all the radiator vents could exceed the supply of steam in which case you will not have control over the system, think of it this way, with excess venting it would be like disconnecting the boiler from the pipes. The steam would come out, but you have no control over it, but, as you said, everything would eventually fill up.

Now if you want it to go where you want, you need a complete assessment of every rad vent, every main vent, location on the system, length of run outs etc. Then, and only then, will we be able to offer any intelligent solutions to your issues.

I speculate the rads, in large part, are over vented and the steam is doing what it does, being lazy. The description of a hot riser next to a cold radiator is described by Gerry Gill in his research on venting. He had to slow one down to get steam to the other. If the steam isn't going somewhere, the only solution is smaller vents somewhere else, not a bigger vent.

ethicalpaul

Jells said:

I have now measured the total EDR as 343, excepting the 2.5" pipe that runs up through the baths. That's 82,320 BTU, right? So there's no way I'm undersized if I"m burning 130k.

No, I don't think that's right. Also, is the 130k the INPUT BTU, or the OUTPUT BTU?

The easier way is to look on your boiler rating plate for the "sq ft of steam" or similarly-marked value and compare that to 343. That value takes into consideration the efficiency of the boiler and the piping losses.

cross_skier

I am late to this discussion but I am also very low pressure like @ChrisJ.  About 0.2" of water column with new Magnehelic gauge not mounted on pigtail.  My mains and risers are vented extremely fast.  I balanced my system by changing out the slow vents on my radiators.  Back in the day my thinking was get the steam to all the radiators fast as a first then use the radiator vents as a final step.

ScottSecor

I think you need to start with the basics. From the few minutes I spent reading it appears that the burner is not producing enough energy to heat the four family house.

Again in very general terms, assuming the "average" apartment has a total of four radiators of "average" size this would typically total about 150 square feet of radiation (aka EDR). 150 x 4 equals 600 square feet of steam. Without looking up your boiler specs I would suspect you would need more than 200,000 BTU input to achieve this output (this assumes 80 percent efficiency with a clean boiler). I have never been to a four family house that is heated with steam that only needed roughly 130,000 BTU input to fill every radiator with steam!

I did not notice what the BTU input rating of your boiler is. I suspect the contractor installed the proper size boiler but I am not confident that the gas burner is providing the proper size flame. Again in simple terms, you appear to have a three gallon pot of water on the gas stove, but unless you crank that burner up a little you will never make that pot of water boil. In other words, get your contractor on site and ask him to go over the burner and the boiler.

Jells

ChrisJ said.

You never told us what vents are on the radiators. At that point, I gave up trying to help.

At that point I did not know, I don't live in the building and I needed to get into the apartments to measure the edr and see what the vents were. 

But venting controls where the heat goes, not it's creation, and this boiler is burning gas continually that does not show up in the system as heat. Heat doesn't vanish from a steam system that doesn't have a leak. If it's burning continually and never satisfies the thermostat or builds pressure so that the cutoff turns it off, every radiator should eventually get heat, right?

Ex: the main to the kitchens riser that feeds three small rads finally got a new Gorton 2 on Saturday. I could feel that it was hot. But the riser in the kitchen just above was still cold. The radiator had been taken off the valve there because I am renovating the apartment. I opened the valve all the way and sat next to it for 15 minutes but nothing ever came out, it stayed cold. There wasn't enough pressure to move the steam 3 ft with the boiler firing continuously.

I'll post all 14 vents later, I don't have the data with me.

ScottSecor

If the boiler is in fact making steam, it has to make enough steam to fill every steam supply, every radiator, etc. IF THE BOILER IS NOT PRODUCING ENOUGH STEAM some of the risers and some of the radiators will not get steam. The steam sometimes collapses before it ever gets to the radiators, regardless of how big a vent you install!

ChrisJ

ScottSecor said:

If the boiler is in fact making steam, it has to make enough steam to fill every steam supply, every radiator, etc. IF THE BOILER IS NOT PRODUCING ENOUGH STEAM some of the risers and some of the radiators will not get steam. The steam sometimes collapses before it ever gets to the radiators, regardless of how big a vent you install!

Wrong direction.

You slow radiators down in that case.
I know Jstar and I know how he works.

If someone else messed with the system there's a good chance it's now far out of balance.

cross_skier

High pressure goes to low.  If he took opened the valve and it stayed cold even though the supply was hot.l then there must be a mysterious vacuum caused by collapsing steam somewhere in the system.

Jells

KC_Jones said:

 You have a venting issue that needs to be resolved. What size vents are on all the rads? The total of all the radiator vents could exceed the supply of steam in which case you will not have control over the system, think of it this way, with excess venting it would be like disconnecting the boiler from the pipes. The steam would come out, but you have no control over it, but, as you said, everything would eventually fill up. 

Let's agree I'm completely overvented. If the thermostat is never satisfied and the boiler runs continuously with the pressure switch never shutting it down, how could there be risers and rads that simply never get heat?

Jells

ScottSecor said:

If the boiler is in fact making steam, it has to make enough steam to fill every steam supply, every radiator, etc. IF THE BOILER IS NOT PRODUCING ENOUGH STEAM some of the risers and some of the radiators will not get steam. The steam sometimes collapses before it ever gets to the radiators, regardless of how big a vent you install!

This is exactly why I think the venting discussion is a red herring...

ChrisJ

Jells said:

KC_Jones said:

 You have a venting issue that needs to be resolved. What size vents are on all the rads? The total of all the radiator vents could exceed the supply of steam in which case you will not have control over the system, think of it this way, with excess venting it would be like disconnecting the boiler from the pipes. The steam would come out, but you have no control over it, but, as you said, everything would eventually fill up. 

Let's agree I'm completely overvented. If the thermostat is never satisfied and the boiler runs continuously with the pressure switch never shutting it down, how could there be risers and rads that simply never get heat?

Because there are radiators that are stealing all of the steam.

BUT if you know better you don't need our help.

Jells

ChrisJ said:

Because there are radiators that are stealing all of the steam.
BUT if you know better you don't need our help.

If I knew it all I'd not be asking. But, sorry, I also require advice to make logical sense to me before I act on it. A rad can only 'steal' so much steam, then it shuts, and the steam goes elsewhere in the system if the boiler is still firing. What part do I have wrong? 'Stealing steam' explanation only works if the boiler stops firing at some point.

ChrisJ

Jells said:

ChrisJ said:

Because there are radiators that are stealing all of the steam.
BUT if you know better you don't need our help.

If I knew it all I'd not be asking. But, sorry, I also require advice to make logical sense to me before I act on it. A rad can only 'steal' so much steam, then it shuts, and the steam goes elsewhere in the system if the boiler is still firing. What part do I have wrong? 'Stealing steam' explanation only works if the boiler stops firing at some point.

No...
A radiator is a condenser and as long as it's radiating heat and you're feeding it steam it's condensing steam and producing water.

The vents job is to let air out so steam can fill the radiator. Once it's filled, it can condense steam at full capacity. Any amount you cool the outside of a radiator below the temperature of the steam will cause it to condense steam on the inside. The cooler the room is, the more steam it will consume, continuously until you stop feeding it. If you were to blow cold air across it, it would really suck down steam, fast. As it condenses steam it creates a vacuum which literally sucks more in right behind it even if there's no pressure.

If you slow a vent up, and only let a radiator fill a few sections it can only condense a fraction of the amount of steam. A 20 section radiator full of steam to the end is slurping down a lot more than one with only 1 or 2 sections full of steam.

ratio

What @ChrisJ said. As long as there's steam making it to the radiator, it's condensing it & actually sucking more steam towards itself due to that 1700x volume change it goes through when it condenses. Slow down the other rad vents, don't speed up the non-heating ones.

@JStar was well respected here, but has there been any work done after he was last out? Any chance the tenants 'helped out' by changing vents?

Jells

ChrisJ said:

Jells said:

ChrisJ said:

Because there are radiators that are stealing all of the steam.
BUT if you know better you don't need our help.

If I knew it all I'd not be asking. But, sorry, I also require advice to make logical sense to me before I act on it. A rad can only 'steal' so much steam, then it shuts, and the steam goes elsewhere in the system if the boiler is still firing. What part do I have wrong? 'Stealing steam' explanation only works if the boiler stops firing at some point.

No...
A radiator is a condenser and as long as it's radiating heat and you're feeding it steam it's condensing steam and producing water.

The vents job is to let air out so steam can fill the radiator. Once it's filled, it can condense steam at full capacity. Any amount you cool the outside of a radiator below the temperature of the steam will cause it to condense steam on the inside. The cooler the room is, the more steam it will consume, continuously until you stop feeding it. If you were to blow cold air across it, it would really suck down steam, fast. As it condenses steam it creates a vacuum which literally sucks more in right behind it even if there's no pressure.

If you slow a vent up, and only let a radiator fill a few sections it can only condense a fraction of the amount of steam. A 20 section radiator full of steam to the end is slurping down a lot more than one with only 1 or 2 sections full of steam.

That all makes sense except for the notion that it can suck up steam faster than steam can distribute to the other risers and rads, assuming there's enough steam being produced. As I've understood the theory, a rad fills with steam till the vent closes. The steam condenses as it gives up it's heat to the rad, and then the rad is hot for quite some time till it gets cool enough for the vent to open and refill with steam. If a boiler is firing continually, that 'refractory period' allows the other slower rads to fill. No matter how widely vented, a rad can't suck up all the heat from a properly sized and firing boiler even accounting for vacuum effects.

I'll say my basic thesis again. The heat from a continually firing, properly combusting boiler needs to show up somewhere. If some rads are sucking up all the heat, those rooms should be broiling! They're not. FWIW I have no doubts that the venting balance in this place is a mess, but I'm unconvinced it's the main problem.

ratio

Jells said:

That all makes sense except for the notion that it can suck up steam faster than steam can distribute to the other risers and rads, assuming there's enough steam being produced. As I've understood the theory, a rad fills with steam till the vent closes. The steam condenses as it gives up it's heat to the rad, and then the rad is hot for quite some time till it gets cool enough for the vent to open and refill with steam. If a boiler is firing continually, that 'refractory period' allows the other slower rads to fill. No matter how widely vented, a rad can't suck up all the heat from a properly sized and firing boiler even accounting for vacuum effects.

Not quite. The radiator fills with steam (under slight pressure), forcing the air out, until the vent closes. When the steam condenses, it's volume reduces by about 1700 times. The radiator will then be at a lower pressure than the system piping and will keep pulling steam into the radiator until there is no more steam to be had (burner off) & then air will be pulled in via the vent. The condensation is an ongoing process.

I'll say my basic thesis again. The heat from a continually firing, properly combusting boiler needs to show up somewhere. If some rads are sucking up all the heat, those rooms should be broiling! They're not. FWIW I have no doubts that the venting balance in this place is a mess, but I'm unconvinced it's the main problem.

If the boiler is sized properly, it's a lot more susceptible to going out of balance. If it were oversized, there would be plenty of steam available even after the fastest-filling radiators are full.

Remember what Sherlock Holmes said. When you have eliminated all which is impossible, then whatever remains, however improbable, must be the truth. Or as least worth checking out.

Jells

@ratio & others: I'm puzzled. Every argument in favor of venting being the primary problem is predicated on the notion of the heat being limited by feedback, of the boiler shutting off at some point due to thermostat satisfaction or the steam pressure switch. But during the cold snaps of the boiler has been running continuously because the riser to the room with the thermostat has been cold. And other radiators were also cold, (I repeat) despite the boiler running continuously.

I have posted the EDR and the gas usage. The heat is not showing up in the system!  Something somewhere would be getting hot!  I'm not trying to do this alone, I am trying to get another tech to take a look at this thing. I've even considered buying my own combustion analyzer, as silly as that might be.

And for what it's worth Jstar never balanced the radiators after he installed the new boiler. It was 9 years ago, and I remember he measured some of them to get the EDR so he saw what was on there, but I am certain there was no balancing after the installation.

ratio

My biggest assumption is that it ran correctly in the past; and I'm taking at face value your assertions that you are not losing water/steam or gas. After that, the most likely is a venting problem, as those are somewhat consumable as well as easily (although perhaps well-meaningly) tampered with.

After that, you've got a real mystery on your hands!

Jells

ratio said:

My biggest assumption is that it ran correctly in the past; and I'm taking at face value your assertions that you are not losing water/steam or gas. After that, the most likely is a venting problem, as those are somewhat consumable as well as easily (although perhaps well-meaningly) tampered with.

After that, you've got a real mystery on your hands!

Why is a sooted up burner and boiler that is not burning the gas properly or transferring the heat to the water not on the table?

ChrisJ

So

The system was never balanced by Joe.

It's burning 130,000 btu/h and feeding a reasonable amount of radiation for the fuel it's consuming.

From the start we've asked you about venting. We've told you repeatedly that it's very important and you've just said it's never been done by the guy that installed the boiler.

You keep saying you have no idea what's going on, we keep telling you but you keep saying it can't be that.


I don't know what to say.

Jells

ChrisJ said:

So The system was never balanced by Joe. It's burning 130,000 btu/h and feeding a reasonable amount of radiation for the fuel it's consuming. 

On what are you basing this conclusion?

ChrisJ

Jells said:

ChrisJ said:

So

The system was never balanced by Joe.

It's burning 130,000 btu/h and feeding a reasonable amount of radiation for the fuel it's consuming. 

On what are you basing this conclusion?

Are you nuts?

Jells

ChrisJ said:

ChrisJ said:

So The system was never balanced by Joe. It's burning 130,000 btu/h and feeding a reasonable amount of radiation for the fuel it's consuming. 

On what are you basing this conclusion?

Are you nuts?

I wasn't challenging your statement, I just wanted to know what you were basing it on. The answer was you were agreeing with my conclusion that the BTUs were appropriate to the EDR. Thanks.

If you want to convince me to go chasing venting ghosts before getting a combustion analysis, you need to explain where all the BTUs are going. They're either going into the water and therefore into the building of which there's no evidence, or they're going up the flue. If the boiler is running continuously the heat doesn't just vanish no matter how badly balanced the venting is!

A building with a boiler running continuously, which it's not designed for, should overheat. Balancing is just that, directing heat from one place to another, with the assumption that the boiler is being shut down by reaching its set point on thermostat or the pressure switch. This is not what we're seeing.

KC_Jones

So, how many days/weeks/months has the boiler been running 24 hours straight without shutting down, at all?

Also what was the result of the last combustion analysis during scheduled maintenance?

ChrisJ

Jells said:

ChrisJ said:

ChrisJ said:

So

The system was never balanced by Joe.

It's burning 130,000 btu/h and feeding a reasonable amount of radiation for the fuel it's consuming. 

On what are you basing this conclusion?

Are you nuts?

I wasn't challenging your statement, I just wanted to know what you were basing it on. The answer was you were agreeing with my conclusion that the BTUs were appropriate to the EDR. Thanks.

If you want to convince me to go chasing venting ghosts before getting a combustion analysis, you need to explain where all the BTUs are going. They're either going into the water and therefore into the building of which there's no evidence, or they're going up the flue. If the boiler is running continuously the heat doesn't just vanish no matter how badly balanced the venting is!

A building with a boiler running continuously, which it's not designed for, should overheat. Balancing is just that, directing heat from one place to another, with the assumption that the boiler is being shut down by reaching its set point on thermostat or the pressure switch. This is not what we're seeing.

No no,

I don't need to convince you of anything and I don't need to explain anything.
I was trying to help you, for free, in my own time. My system works very well. I do not have any heating issues so I'm not the one asking for help.


Whether or not you do anything with it is up to you.

I'm not sure why an issue that should have been solved in a day has already taken two weeks to fix.

Jells

KC_Jones said:

So, how many days/weeks/months has the boiler been running 24 hours straight without shutting down, at all?

Also what was the result of the last combustion analysis during scheduled maintenance?

Last March the boiler was dirty, I don't have the report. The tech said he didn't do it on Sat because the call wasn't for routine maintenance! I've told him I'm not paying for the huge repiping of the returns he suggested without a combustion analysis.

The runtime varies. Here's a sample graph and the weather that week. This recorder is on the vent pipe of the boiler. You can see it fired continuously for over 48 hrs.

EBEBRATT-Ed

Do a combustion test or at least take a stack temperature . That will tell you if the boiler is absorbing heat

PCapNJ

RE: where your BTUs are going... could it be possible that one of your tenants is opening a window because one of the radiators is too hot thus causing a radiator that is pulling most of the steam? Food for thought, fwiw.

Jells

EBEBRATT-Ed said:

Do a combustion test or at least take a stack temperature . That will tell you if the boiler is absorbing heat

Thanks. I'm trying to get any tech here to do a combustion test. Is it stupid for me to buy one of the $400 units? That's like one service call! But I read they're fussy and need frequent calibration.

Can you elaborate about stack temp? I have a cooking thermometer with extension probe and graphing capability that I can put in the hole for analyzer probe. What exactly would I be looking for? What should the normal range of exhaust temp be?

@PCapNJ I wish it were that simple! They know I'm trying to get the heat tamed. In fact the bigger problem was telling the tenant with the thermostat in their living room they couldn't use a space heater in there because it'll tell the boiler to turn off!

Dave in QCA

I'm sorry for coming late and also sorry if I have missed a point in the conversation.
To Me, this sounds like the classical situation of radiators being over vented. I have spent huge amounts of time on a property, trying to figure out why a radiator would never get steam. My mind went to possible clogs in the steam line, and every other possibility that I could think of. Then, I read some comments on a system on this site, I think it might have by the Steamwhiperer, and it was from others too, including Dan. The age old problem, so often overlooked, is over vented radiators.

In the system I was working on, when I went around and very carefully adjusted the Hoffman 1A vents to about what a Hoffman 40 would be (you have to take the screw off and actually look at the hole alignment)
After the venting on ALL of the radiators was slowed down, the system starting working perfectly. The radiator that would NEVER EVER get any steam at all, started heating at the same rate as the rest of the system and the fast radiators were slowed down.

Vent your Mains very fast and your radiators VERY slow.

I'm curious to see how this problem works out.

Jells

Dave in QCA said:

I'm sorry for coming late and also sorry if I have missed a point in the conversation. To Me, this sounds like the classical situation of radiators being over vented. I have spent huge amounts of time on a property, trying to figure out why a radiator would never get steam. My mind went to possible clogs in the steam line, and every other possibility that I could think of. Then, I read some comments on a system on this site, I think it might have by the Steamwhiperer, and it was from others too, including Dan. The age old problem, so often overlooked, is over vented radiators. In the system I was working on, when I went around and very carefully adjusted the Hoffman 1A vents to about what a Hoffman 40 would be (you have to take the screw off and actually look at the hole alignment) After the venting on ALL of the radiators was slowed down, the system starting working perfectly. The radiator that would NEVER EVER get any steam at all, started heating at the same rate as the rest of the system and the fast radiators were slowed down. Vent your Mains very fast and your radiators VERY slow. I'm curious to see how this problem works out.

Thanks Dave. I do understand the concept, but the heart of my argument against venting being the primary problem is that the situation you were in was predicated on the boiler actually shutting down at some point when the thermostat was satisfied. If your boiler ran continuously for days at a time, that problem radiator would eventually have gotten the heat, right?

ethicalpaul

We know that the sq ft of the conditioned space is not directly relatable to the correct size of the steam boiler, but just for curiosity's sake...what's the sq feet of conditioned space?

EBEBRATT-Ed

@Jells stack temp under 320 is low meaning the boiler is underfired.

at about 550 and up I would be wondering if the boiler was sooted on the fireside, scaled up on the water side or over fired and at 650 I would think for sure something is amiss

Jells

ethicalpaul said:

We know that the sq ft of the conditioned space is not directly relatable to the correct size of the steam boiler, but just for curiosity's sake...what's the sq feet of conditioned space?

Well, only the 3 1k sq ft units have radiators. The basement studio is warmed by the insulated mains passing through it, as is the boiler/laundry room. So 4k total, but only 3k by rads. The building is 45% attached on both sides, and one side of the unattached portion has the stud bays filled with brick masonry. My guess is that was a firewall of some kind.

KC_Jones

EBEBRATT-Ed said:

@Jells stack temp under 320 is low meaning the boiler is underfired.

at about 550 and up I would be wondering if the boiler was sooted on the fireside, scaled up on the water side or over fired and at 650 I would think for sure something is amiss

^^^^This.

You show a maximum temperature of 114.4° and say the boiler is firing. If that is really true, something is seriously wrong.

Jells

EBEBRATT-Ed said:

@Jells stack temp under 320 is low meaning the boiler is underfired. at about 550 and up I would be wondering if the boiler was sooted on the fireside, scaled up on the water side or over fired and at 650 I would think for sure something is amiss

Awesome, that's something I can sink my teeth into! By 'underfired' do you mean incomplete combustion is taking place?

Jells

KC_Jones said:

EBEBRATT-Ed said:

@Jells stack temp under 320 is low meaning the boiler is underfired.

at about 550 and up I would be wondering if the boiler was sooted on the fireside, scaled up on the water side or over fired and at 650 I would think for sure something is amiss

^^^^This.

You show a maximum temperature of 114.4° and say the boiler is firing. If that is really true, something is seriously wrong.

Sorry, I think I misremembered where the thermometer was placed, not that it's a internal measurement anyway. It's actually on the crosspiece of the steam header sitting on a terrycloth pad. The only purpose I had placing it there was to get a read on the cycles, not to learn anything from the temps it was getting. I'll be putting a probe in the vent pipe that can, via bluetooth to my phone, graph the temps. I normally use it for roasting turkey and smoking meats. It's probe is rated to 716°F, I guess we'll see...