Oversized boiler - how to reduce gas pressue

ALIGA

I suspect my home has too large of a weil mclain gas steam boiler 250k btu. I dont have any calculations to back me up, but the home is roughly 2600 square feet with 12 boilers.



The pressuretrol kicks in at 1.5psi, when the thermostat is not satisfied. My gas bills in the winter are thru the roof.



Is there a way I can lower the fuel consumed by the boiler? thank you in advance.

nicholas bonham-carter

Large bills

To start, you could try to adjust the pressuretrol down to .5 psi cut in, and 1.5 cut out. Over pressure is a real gas hog, as you may only need 2 ounces of pressure to heat all the radiators. I suspect the pressure was turned up by some well-meaning, but unknowlegible serviceman to compensate for a lack of main(not radiator) venting. Locate your main vents, and take a picture which you can post here, and we will tell you whether they are up to the job of allowing the air to escape with no resistance. Post some pictures of your boiler piping as well.

I am sure your boiler is too large, but getting the air out easily will save fuel.--NBC

ALIGA

You are correct

initially the ptrol cutin was set to 2 or so. I reduced it down to .5 lowest it will go. I also added in a 5 psi gauge, and see that at around 1.5psi it cuts off. At the end of the main vent is a bronze colored vent, I suspect a Gorton.



I have been reading about downfiring, closing off burners, etc. Trying to reduce the cycling as the radiators are heating up, but the thermostat is not satisfied, and it feels like the boiler runs, and then turns off.

Hap_Hazzard

Where to begin...

The correct size of the boiler can only be determined by surveying the connected radiation load. If you can tell us the sizes of all your radiators, in columns, sections and height, and post some pictures so we can help you identify them, then someone can look up the ratings. Or, if you prefer to do it yourself, you can find ratings for most of the more common radiators in the library. If all your radiators aren't in there, there's a book you can buy that has just about all of them.



You can't assume, from the fact that the boiler is cycling on pressure, that the boiler is oversized. First, if your main venting is inadequate, the pressure will be higher. Do you know where your main vents are located? Are they the right kind, and are they working properly? We can help you sort this out, but we need that information.



Second, the burner might not be adjusted correctly. Homeowners occasionally turn up their burners to compensate for poor performance. Inadequate main venting and removal of insulation from the piping are usually the root cause, but it's easier to turn a screw than fix the real problems. Unfortunately it can also cause dangerously high CO levels and set nearby combustibles alight when the burners kick in. You should have a technician do a combustion analysis if you haven't already done so.



There are lots of things you can do to make your fuel bills lower. Read through some of the threads here and see what you can learn. You might also want to get a copy of Greening Steam, available from the Shop.

Hap_Hazzard

What kind of LWCO do you have?

If you have a Hydrolevel CycleGard, they shut off the burners every ten minutes regardless of pressure or temperature. There is a green light on top that indicates when it is in shut-down.



By the way, Mr. Bonham-Carter has studied main venting and pressure control extensively. He can give you good advice on that. I've take a lot of his suggestions, and they work.

ALIGA

Thanks HAP and NBC

Let me take pics of the Gorton, and see if that is venting air when the unit kicks on from a cold start.

Hap_Hazzard

Start measuring those radiators too!

And get that combustion analysis. The tech will be able to tell if the firing rate is too high or if it can be downfired. What kind of burners do you have?

ALIGA

I have some pics

It looks like there are two mains, I can see the end of one, and it looks like it has a small Gorton. I also have attached a pic of the weil mclain jacket, seems like a lot of rust buildup. Lastly there is a pic of a potential antler setup where I can install larger vents. I noticed while the main was warming up, there was no sound of air releasing out of the gorton.



pics are here: https://plus.google.com/photos/101487885737658497414/albums/5811211541527838801?authkey=CPjA8ZiwuZ2VgQE

Hap_Hazzard

Oh my.

You've got some problems with your near-boiler piping. The header is too low to prevent carryover and much too small in diameter, and as someone recently pointed out here, anything you do to improve the venting and lower the pressure is going to increase the steam velocity through the header and extract more water from the boiler. This is something that needs to be corrected before you can address the other problems, and it's not the kind of thing you can tackle by yourself in November. I redid my near-boiler piping myself, but I spent all summer planning and working on it. Unless you want to live with it the way it is until spring, I think you're going to need a good steam man to repipe your boiler. Where are you located?

ALIGA

Location lower NYC

I am in queens, ny. I will tackle it myself with the great knowledge found here. Do you think one Gorton 2 will be sufficient. The current one does not seem large enough to be a Gorton 1 or 2.



Can you comment about the rust. Any ideas on that. The boiler is at least 22 years old. Thank you.

nicholas bonham-carter

About that rust

This is the time to pay close attention to any excess water your boiler may use. If you have an auto filler, valve it off, and mark the water level using a clothespin on the sight-glass rods. Check it often to see if you are losing water. Obviously, that rust shows signs of a leak, and who knows how close the end will be for the boiler.--NBC

Dave in QCA

Check for Leaking Sections

Oh my!  This does not look good!  In addition to several piping issues, I am most concerned with the rust that is appearing on the access plate immediately above the burners.  There is normally not any moisture or condition in this area that would cause rust.  I am very suspicious that you may have a leak or a hole in your boiler located above the water line.  The only time it would actually leak is when the boiler is runing and it might manifest itselt in the appearance that I am seeing in the first photo.



Your boiler needs to be inspected ASAP.  Take the top of the boiler off.  The remove the insulation blanket.  Next, remove the cover that is called the flue collector.  This will let you look directly at the top of the cast iron sections and even down in between them.  Take pictures and post them.  The iron should be reasonably clean, not accumulations of flaky rust and white residue.



I wish you the best luck, but this does not look good.

ALIGA

Hi Dave

I will try to take the covers off, I bought this place one year ago. The boiler is at least 22 years old, it was installed in 1990. I hope I can get a few more years out of it.



Worst case scenario if it does go, should I be looking at a weil mclain replacement, or are there better options out there. thanks.

BobC

Lets hope the boiler is ok, BUT

if worse comes to worse and it has to be replaced you have to find an installer that knows steam. The quality of the installation matters more than the brand of the boiler.



Also you should buy a couple of books on this site ("We Got Steam Heat" and "The Lost Art of Steam Heat"). the first is a beginners guide to steam heat, the second will give you all the information you need to understand exactly how steam heat works. Both are well written and easy to understand. If you are to have to replace a boiler or oversee extensive repiping you have to understand steam so you get a good system that will last a long time.



good luck,



Bob

ALIGA

thanks bob for the insight.

Hi Bob, I understand what you are saying. I am planning to attend one of Dan's seminars when I have some breathing room.



However, I dont trust many of these installers. When I moved into the place, there was a bunch of stickers on the boiler jacket, I am assuming the licensed plumber who isntalled it. The pressure was not set correctly, etc. From the great knowledge found on this board, I am learning more and more. When it will be the time to install a new noiler, I will love to be as hands on as possible. I am not scared to get my hands dirty.



I dont need a plumber, i need a steam head!



I will be purchasing the books soon.



One of my goals for this weekend is to install more venting at the end of the line.

Hap_Hazzard

About the vent

Aside from the #2, Gorton vents are all the same size, so that could be a #1 or a 4, 5, 6, C or D. The only way to tell is to get a closer look at it.



Whatever you replace it with, I suggest you get a 6–10" nipple to mount it on to prevent the water from damaging the vent, because you're going to have some wet steam until you get the near-boiler piping fixed.



I hope your sections aren't leaking. That would be a tough break. But if you need a new boiler, at least you'll be able to get one that's the right size for your radiators and get it installed right.

BobC

I agree the vent sb moved

I agree with Hap about moving that main vent. Last year I noticed my Hoffman 75 seemed to not be closing completely. It was mounted on a T at the end of the main where it dropped down to a wet return. My old boilers header was only about 15" above the NWL and so I suspect my steam wasn't very dry.  I boiled that vent in vinegar to clear out the deposits that were preventing it from closing completely.



I installed an elbow and ran a foot back up the pipe slope where i put a 3' nipple and the main vent. So far that vent is holding up fine. Your piping looks like you are dealing with wet steam so I would move that vent to protect it; try to put it somewhere where you can add more vents if you have to.



Bob

ALIGA

Gorton C valve replaced with a Gorton D

Gorton C at the end of the main was not in good shape, after replacing it, and cranking up the heat I heard air coming thru it. Sounded like the air vented pretty quiickly and then steam filled the main.



Would it make sense to also add a Gorton 2, or is it overkill? could potentially save me 60 bucks on a valve. Please advise.



I would like to cut open the gorton C and look inside of it, any idea what may have caused it to stop functioning?

nicholas bonham-carter

Money well spent

You can never have too much venting on the mains; but not so on the radiators.

If you have room for a gorton #2, then use it. Don't be penny wise and pound (or dollar) foolish.

The rads should start out being slowly vented, so that the steam will be starting to move up all the risers at the same time-simultaneously-all the rads getting hot at the same time-pats of butter all melting on the radiators at the same time. I hope I made this sound important!--NBC