zero pressure on boiler

JHprovidence

I am a renter and have been working with my landlord to get the heating system to be more efficient. I have replaced all of the broken vents with mostly gortons after using the venting capacity chart, but I can't seem to get them all to close. The thing is the gauge on the boiler never goes above zero. There is not a gauge on the pressuretrol so I am wary to keep creeping that up without having much knowledge on boilers. It is a old ARCO boiler. I think the model is a 1902 S. Also it is a counterflow system and sadly it has no main vents



questions:

1. Why is the boiler pressure reading zero?

2. Should I keep increasing on the Pressuretrol? it is currently shy of 5 psi

3. There are two pipes that go nowhere. They once went upstairs but they have been cut off and sealed at some point. Could these be causing problems

4. Has anyone worked with a good steam person is RI if I can convince the landlord to add main vents?

5. Which one of Dan's books would be best for someone who is a renter, inexperienced, and has a counterflow system?



*in the third picture the first pipe goes upstairs and is cut off at some point. There is a second one that does that further down the main line.

MDNLansing

As a Homeowner

Here are a couple of things from my POV. If some of the vents stay open, you won't build much, if any, pressure. You need the system to seal up tight to get pressure to build. The vents are designed to allow air to escape, then close off once the steam gets to them and they heat up. Either they are faulty and not closing with the steam, or the steam never gets to them and they never heat up.



Are the vents getting hot and staying open, or do they stay cold and open? If they get hot but stay open, they need to be replaced. If they never get hot, then you have an issue of steam not reaching the radiators properly.



As for main venting, you need it. Period. Inform the landlord that the lack of vents and pressure is hard on the boiler. You didn't mention who pays the gas bill, but that is seriously affected by this as well. The boiler is running far too long and hard to heat the house.



Without vents on the mains, I suspect your entire system is trying to vent through the radiators. As the boiler runs, it will take a very long time to vent the entire system this way. While it's running, eventually enough heat is put off by the radiators and the thermostat stops calling for heat. All without building any pressure in the system. It is is very expensive to operate like this.



The pressuretrol only affects the burner based on system pressure. Once the pressure hits a certain point, the burner shuts off. Pressure begins to fall and when it hits the low limit on the pressuretrol, it kicks back on. That is, if the thermostat is still calling for more heat. No matter what you set the pressuretrol at, it won't do anything unless pressure is being built and relayed to the controls. If you truly have no pressure, its a useless contraption on your boiler.



Once you get some pressure and efficient heat, your system should only run for a few mins at a time. So, thermo calls for heat, boiler fires up, runs to the high pressure limit, shuts off until the low limit is reached, then fires back up again. This process happens over and over until the thermo says, no more, it's hot enough.



I have a big old system in a big old house. When my thermo calls for heat, my boiler fires up, runs for 5 to 10 mins and shuts down. I've dialed mine in to be efficient enough so that only one cycle is needed to raise the house temp 4 to 5 degrees. So, my boiler only runs about 10 mins every couple hours. Granted it's not all that cold out yet, but you get the point. Even an old system, in an old drafty house, can run well and efficiently.



You need a pro in there yesterday. You either have no pressure and are throwing dollars out the window. Or you are in fact building some pressure but your control and safety devices aren't working. Either way, landlord needs to at least pay for a system inspection by a pro. ASAP.

Rod

Old Boiler Problems

Hi- DO NOT keep increasing the pressure setting on the pressuretrol ! Are you getting steam to any of the radiators? If so, which ones? The ones closest to the boiler or farther away? 

Do you feel air coming out of the radiator vents? Don't test this with your bare hand as steam can give you a bad burn! Use a strip of newspaper and hold it near the vent outlet to help you detect movement.

That's a really old boiler and the efficiency is probably quite a bit lower than a modern boiler. Has the burner been checked lately by a pro?

Main Vents-  A Counterflow system needs main vents at the far end of the main from the boiler. Air out of the main faster means steam to the radiators quicker which results in less burner "on time". Less burner "on time"  means less fuel is used. I can't think of a better reason than that which would convince a landlord that they need main vents!

 

Rhode Island Steam Pro -  Here's a link to Steam Pro that is listed in the Find a Contractor section at the top of the page, http://www.heatinghelp.com/professional/263/Gronski-Plumbing-and-Heating-Inc

 Steve Gronski has done some really nice work on counterflow systems.

- Rod

Ironman

Pressure

No residential steam boiler should ever be set above 2 psi. Most are set even lower. Turn the pressuretrol back down. You actually waste fuel and cause more problems by having it set too high. The gauge is probably not functional.



As mentioned, you need a pro in there.



Dan's book "We Got Steam Heat" is a great primer. It's available in the book store.

JHprovidence

Radiators are filling

Everything is moving along until the last radiator which is huge gets near filling… then things are just strange is all i can say. I can get all the vents to close using different brands of vents, but I have to make the system much slower. Also all of the radiators do not fill until the giant one does and of course since there are not main vents steam likes to favor the closest rad on the main.



When it comes to Steve Gronski, have you had work done by him or know people who have had work dome by him?

Jamie Hall

If things are as you say...

you are in pretty decent shape.  You  probably do need main vents, which will help even out when steam gets to the various radiators.



It is not at all unusual for a steam heating system to not raise significant pressure -- particularly if all you have to read it on is the required 30 psi gauge.  If the system is balanced reasonably well, all the steam produced by the boiler is condensed in the radiators, and the pressure at the boiler will never go over a few ounces.  The only exception to this is on recovering from a very deep setback -- say over 5 degrees on a cold day -- when the boiler runs long enough so that all the radiators are fully hot.  Then it may cycle off on pressure.  But that's rare.



As has been said, dial that pressuretrol back to 2 psi shutoff (some are additive differential, some subtractive -- make sure which you have, and the be sure to set it so that the cutout will be not more than 2 psi (1.5 is better, but you may not be able to get there with a pressuretrol) and the cutin then should be around 1 psi.



I might warn you that if the pressuretrol is set much over that, and you do begin to raise pressure, there's a good chance that you will ruin the vents (as well as burning a lot of fuel you don't need to) -- they don't like high pressure.

nicholas bonham-carter

Old boiler in RI

You should check the pressure with a new gauge, after cleaning out the pigtail , as I suspect it is over pressure which is preventing the vents from closing.

In the absence of main vents, you can sometimes put Gorton D's on the last radiator on a main, but that is not as good as havering a real main vent.--NBC

JHprovidence

boiler size

one piece of info I did not include. This boiler at one time heated more than just the first floor. Now it heat just the first floor and I have 134 square feet of radiators on the system. I am sure the boiler is way oversized. Also when we have skimmed it. The sight glass takes about 10 min to refill.



Thanks to everyone for all of their comments. I have now done my best to set the pressuretrol at 2psi. Since there is not a gauge I turned it to five and counted until five turns got me to the bottom and then turned two up. If anyone has a better method I would love to hear it. Now that I have done that I think I just had it at two and a half before.



NBC I tried a gorton C but the speed causes some water hammer issues in the pipes so I pulled back to the 6

VA_Bear

JH's gauge looks like it is on a buffer Nick.

I'd bet the gauge buffer is full of garbage and would recommend reducing the Pressuretrol to 2 PSI cut out and 1 PSI differential, replace the gauge with a 0-5 PSI steam gauge and replace the buffer with a 180 degree steam pigtail to protect the gauge from direct steam exposure.



JH, if you turn the pressure control down to 1 PSI, does the boiler shut off automatically? This is a quick check to determine if the gauge is the problem or if the boiler is not producing pressure. I have also attached a low pressure gauge to the boiler drain with a hose bib adapter (Lowes or Home Depot) to check the jacket pressure. The water is the same pressure as the steam.

ChrisJ

Buffer?

VAbear, if I may ask what is a buffer and how does it work?

JHprovidence

thought better pictures might help

I will try reducing the pressuretrol on the next cycle but I am pretty sure that it was all the way at the bottom when I first started to play with it.

ChrisJ

Pressuretrol

I'm a homeowner and not a pro,

I have a pressuretrol like that.  I decided not to use it and to use a mercury type I had instead as it worked much nicer at lower pressures.  What I found was the style you have even all the way down wasn't kicking off until almost 3 psi.



I'm not sure if anyone has asked but have you been testing and blowing down the low water cutoff weekly?  Please make sure you do a blowdown with the burner on so you can ensure the burner turns off every time.  This is very important and it seems like most do not realize they must do it with the burner on. 



Personally, I would also try and replace the pressure release valve with a new modern one but that could result in disaster so please proceed with great caution.  I just did one on my neighbors 80 year old 3 pass boiler and the original came out with no problem but I've got a feeling it often doesn't turn out that way. 

Rod

Rhode Island Steam Pro

Hi - My home is in central Maine so I don't have any personal experience with Mr. Gronski other than from seeing pictures of a 2 main counterflow system that he did. It is excellent work!  I'll post the pictures below.

As other have mentioned you might want to check the gauge pipe to make sure it is open.

You really need some main venting. It isn't all that hard to tap the pipe and install a vent.

- Rod

JHprovidence

which one is the gauge pipe

Sorry for my ignorance. Which one is the gauge pipe?I am from Tennessee and have never experienced anything beside central heating and air up until two months ago. I have gone from "what! they don't have ac to what hell is all of this hissing and banging!" Thank you for the pics of mr Gronski's work. I am trying to arm myself with as much info before I approach my land lord about what I can't do on my own.

Rod

Buffer = Snubber?

Hi Chris- I think this is the same as a "gauge snubber"

  Ray Gauge snubber  http://www.raysnubber.com/

  Porous for Steam - Part # 32627  - 1/4 “  NPT Stainless

                                  - Part # 32618  - 1/4 “ NPT Brass

- Rod

Rod

"Gauge Pipe"

Hi- The "gauge pipe" is what connects the gauge to the boiler. The bulge below the gauge is what we are calling the "buffer" or "snubber". This and/ or the gauge pipe may be plugged up.   

   Good steam pros are very busy at this time of the year and it isn't necessary to use one as any plumber or handy hand should be able to install a main vent on the top of the steam main at the end of the pipe.  However I would give the landlord that steam pro contact so when he needs to replace the boiler he will be able to get the right person who really knows steam to handle the job.  If you stick around this board a while you will see many botched installs by people who were supposedly "steam experts"

- Rod

JHprovidence

directions for plumber

is there any thing I should read before instructing a plumber where to tap the pipe

Rod

Main Vent

Hi - It might help if you could post a picture of the end of the steam main and the length and size of the main so we can determine how much venting you will need.

- Rod

VA_Bear

Closer to a pigtail Chris

Some of the little globe shaped devices similar to what JH shows below his pressure gauge are water filled devices with a convoluted internal passage which does the same job as a conventional pigtail by transmitting the pressure through an isolating water column (I came across some in an OLD!!! (1880s) system my family machine shop was involved in and cut them open to get a better idea of how they work. It could be a snubber, however I don't recommend them on a steam system for two reasons: First a snubber has a very fine porous metallic mesh which isolates the gauge from dramatic pressure variations by forcing the fluid flow to take several turns and reduces the shock effect on the gauge sense element. This mesh also acts as a filter media and traps debris (it loves grabbing very fine rust particles), causing it to clog easily on steam systems and restricts the pressure passage over time. Second, a snubber offers much less protection from direct steam exposure to the gauge element than a pigtail or a buffer and shortens the life of the gauge significantly. Most residential steam systems don't have a problem with sudden pressure shocks to the gauge and the snubber is not needed. Commercial and industrial systems which need snubbers usually install them on the gauge/sensor side of a pigtail which protects the snubber and the gauge.



This is why I recommended the replacement of the buffer with a pigtail, if nothing else because the buffer is more prone to clogging than the pigtail is due to its design and material.



Hope this helps.

VA_Bear

Great advice Chris

Testing the operation of the pressure relief and blowing the low water cutoff down are critical for the safe operation of an automatic boiler. The pressure relief can keep the boiler from turning into a NASA worthy missile and the low water cutoff keeps you from cracking a boiler jacket and pulling out several thousand hard earned dollars and going without heat in the middle of winter (every pro here and most of the amateurs know Murphy's Law has a special affinity for HVAC/R systems!). Even though local codes have only recently enforced a manual reset second low water cutoff device on residential and light commercial boilers, I have recommended an electronic probe manual reset low water cutoff since I first began working on boilers with any regularity (about 15 years on and off now). If you want to know why, Check out the video below (Thanks to Mythbusters) and remember that at it's heart, a steam boiler is just a water heater which is not flooded out...



http://youtu.be/rGWmONHipVo



and



http://youtu.be/9bU-I2ZiML0

JHprovidence

end of the line

the main line is 26 feet. it also has a branch that comes off at the at the beginning that goes to a riser that goes to the giant radiator in the living room. That branch is 12 feet



1. End of the main

2. The branch I talked about

3. End of the branch before the riser