Security Seal Facebook Twitter GooglePlus Pinterest Newsletter Sign-up
The Wall


Joined on September 15, 2010

Last Post on September 16, 2014

Contact User

Recent Posts

« 1 ... 84 85 86 87 88 89 »

High pressure

@ October 23, 2010 9:10 AM in Boiler Question

A residential steam system operates below 2 PSI by law. Even the empire state building heats all 102 stories on 2-3 PSI. I still don't understand why they never designed a pressuretrol that has better resolution at the low end. You actually can replace the pressuretrol with a vaporstat and then you can run the system in ounces but that is a subject that we don't have to have right now..

The grey box besides the pressure gauge is called a pressuretrol, it shuts the boiler down when it reaches the set point and allows it to restart once the pressure falls to another set point. It looks like the front control (the pointer on the front of the box) is set as low as it can go (0.5) which is good.

If you take the front cover off this pressuretrol (a single screw) you will see a white thumbwheel dial that should be set as low as it can go (1 or less). Make sure the power to the boiler is off (turn off the circuit breaker or remove the fuse) before adjusting this wheel - better safe than sorry. You cannot adjust it too low so don't worry about that.

If the gauge reds 0 when the boiler is cold and 5-10 PSI when it is steaming then it seems to me you either have a blocked pipe (See JPF's post above) or a bad pressure control. Pressuretrols are not precision instruments, I had two of them go flaky (high pressure) in 13 years. At this point you have to determine if your comfortable doing this yourself or you want a pro to do it for you. If you do it yourself make sure you buy the right part, take the model number off the one you have so you can match it up.

Once you are sure the pipes leading to the pressuretrol and gauge are clear and that the pressuretrol is set up correctly, the chances are you have to replace this control. It's just a matter of disconnecting all power and then removing two wires (make a diagram so you know where they go) and disconnecting the flex cable that connects to the pressuretrol. Then twist the pressuretrol off the pigtail apply some teflon tape to the pigtail and twist the new one back on. Put the flex cable into the new control and hook up the wires. Adjust the two controls, power everything back up and you can run the boiler and see if everything is happy.

good luck,


Pressure drop

@ October 21, 2010 12:41 PM in Question on boiler pressure

I'm a homeowner and have been tweaking my system for the past couple of years. Right now, because my boiler is really too big for the job, the system tends to cycle on and off for about 10 cycles before the thermostat is satisfied. I have my vaoporstat set to cut out at 16 oz and back in at 3 oz, it takes i min 17 seconds initially and finally 2 min 5 seconds for my system to fall to the cut in point. That data was recorded last year in February, the data is in the attached pdf file.

I tried going down to 12 oz cut out but felt the system was running as efficiently there so I moved it back up yo 16 oz cut out. I never tried moving the cut out lower than 13 oz.

Are all of your basement pipes insulated?

Stopping one radiator

@ October 21, 2010 9:00 AM in turning off an individual steam radiator

Putting in a 1/8" plug should stop that radiator from heating, if it doesn't then there must be a leak in the radiator.



@ October 20, 2010 10:06 AM in Some basic questions

Dave's comments below are all very good and should be followed.

In you original post you said the main with the Hoffman 75 and all of it's radiators heated fine but the one with the Gorton #2 didn't seem to heat up as well. Does the pipe below the Gorton vent get steam hot? If I understand your description this main runs out 16' and then T's off - the 14' side has the wet return and Gorton vent while the 8' side has no venting. Have you checked the slope of this short main to make sure it slopes towards the return? Without a vent on the short side of the main the steam is not going to go there untill everything else is full. If the radiators on this short side of the T are not heating I would find a way to add a vent to this main. If that isn't easily done then those radiators should have larger vents on them because they have to vent the main as well as the radiators. It seems the T shaped main just needs more venting assuming all the piping is sloped correctly.

Also that third floor radiator without a vent in it will steal the steam from everything else on that main. Try to make a chart that shows how long it takes the boiler riser pipe hot and then how long it takes the end of the short main and both ends of the T main to get hot. Then determine which radiators the mains feed and which of those are not heating correctly. This should be done after putting an air vent back in that 3rd floor radiator.



@ October 19, 2010 7:37 PM in We Got Steam

Your description and the pictures give me no reason to suspect the system isn't safe to run. Do you know when it was last serviced? It might be worth having someone look at the system and show you how to keep it in good working order. He can show you where the vents are (or should be) and tell you about any irregularities the system has.

I'm just south of Boston so I haven't a clue about contractors in your area. If you look under the FIND A CONTRACTOR heading you can go down to the states section (the zip code search doesn't work right) and see which ones are in your area. There should be some good men in your area because there's a lot of steam in Detroit. With any luck, one of them will see this thread and give you a heads up.

I bought Dan's "Lost art of Steam Heat" and Greening Steam books last year and i found them just packed with good information. The books are listed under the SHOP heading. In the mean time take a look at this article -

Getting that ceiling radiator back in place will take a few good strong young men, I know I'm way past that stage. The first thing is to try and figure out why some of you radiators don't seem to be getting steam but that's usually a bad vent, bad inlet valve or piping/ radiators that are sloped the wrong way.

good luck,



@ October 19, 2010 2:30 PM in Boilder is not starting...

The pressuretrol will open the circuit when the boiler pressure goes above the set-point (usually 1-1/2 or 2 PSI), when the pressure falls below the differential (usually 1/2 PSI) the switch will close and allow the boiler to start.

On the front of the pressuretrol you will see a screw that will allow you to remove the cover, inside you will see the switch with two wires leading to it. If the boiler has been off long enough for the pressure to drop off the switch will be closed and there will be no voltage across it.

BTW sometimes just a good rap with the plastic handle of screwdriver will cause an intermittent switch to close, when I was a tech at the post office I fixed more than one switch by doing that.


Won't start

@ October 19, 2010 1:20 PM in Boilder is not starting...

If you have the boiler manual and a voltmeter you can go through the wiring diagram and see where the power stops. If the thermostat is good the two safety's that will lock the system off are the LWCO and the pressuretrol.

When pressuretrols get iffy sometimes the switch inside doesn't close and will prevent the system from starting. Go through all the wiring to make sure something isn't just loose or corroded. just be careful so you don't get lit up.


Near boiler piping

@ October 19, 2010 12:13 PM in We Got Steam

It looks like this system has no real header or equalizer or anything resembling a hartford loop. It's single pipe and probably a parrallel flow system.The question is does it heat the house without any undo banging and clanging?

In the best of worlds you would want to correct the problems in the near boiler piping but with a boiler thats 30+ years old you have to be careful about tearing things apart less you end up looking at an emergency boiler replacement.

I'd look at the mains venting as well as the radiator air vents first, some of them might be defective. A plugged up main vent will cause radiators to heat slowly and partially. A plugged radiator vent can cause a radiator not to heat at all. Also make sure the steam piping slopes towards the boiler return pipe. While the system is steaming check for steam leaks at the supply valve at each radiator and make sure all the radiators slope back towards that supply valve.

If you can't hear the radiator air valve venting air before and while the radiator gets hot use a piece of tissue paper to see if there is any air movement.These are the kinds of things a homeowner can do without getting into too much trouble Once you understand how steam works and are familiar with your system, you can do more involved work. Hopefully the steps above can get you through this winter.

Once you do find a good steam pro, have him asses the system and the pro's and cons of fixing whats there or a replacing the boiler.

good luck,


radiators not heating fully

@ October 19, 2010 10:22 AM in Radiators only hot halfway through?

Does the heating system satisfy the thermostat and does the house heat up? How did the system perform last year during the cold? During weather like this radiators will often not heat all the way across because it is cool but not really cold out.

I agree with what Joe V said about possible issues and that calling a good steam man might be your best bet if your not familiar with the system. If you do call someone in watch what he does and learn. Also if you look under the SHOP heading of this web page you will find some books offered for sale. If you are new to steam you should look at -

That book will give you a good understanding of steam heat. Then you can look at "Greening Steam" and "The lost Art of Steam Heat" if you want a deeper understanding of the system.



@ October 19, 2010 9:05 AM in Sight Glass / Water Level Question

We don't usually discuss cost in this forum but to me, the costs this
person is quoting indicates he really doesn't want the job. If he does
get the job, he padded enough into it to ensure he has covered all the

I suggest you get a qualified steam guy in to look at things and ask him if you can observe so you can learn what to do for normal maintenance.

I had to replace my sight glass and gaskets last year and cost me about the cost of a 12 pack of Sierra Nevada's Pale Ale for the parts; I installed the parts myself in about 10 minutes and most of that was spent scraping what was left of the old gasket out of the bonnet nuts. Many years ago the tech replaced the glass and gaskets as part of the annual cleanout and the additional cost was pretty small. I usually tell the guy doing the annual cleanout to let me know if anything additional has to be done because he's already there and it saves the cost of another service call.


Main valve replacement

@ October 18, 2010 1:47 PM in Spitting Main relief valve would like to cover

Getting that old valve out can be a challenge, by all means have your serviceman replace the main air valve if you don't want to do it yourself.

Covering the valve is fine as long as there is space between the output of the valve and the cover. It sounds like you will have more than enough space for the valve to work properly and you can access it for servicing..


Spitting main

@ October 18, 2010 12:30 PM in Spitting Main relief valve would like to cover

A Main valve that spits is defective and has to be replaced. If the mains are about the same size you can just replace it with one like the newer one, assuming the system is working well - the heat comes up quickly on the side with the newer vent.

I would not box a vent in, leave an access panel so it can be serviced. Maybe you can plumb the air valve away from the rim joist with a couple of 90 degree's and a short nipple. If you put a box around the NEW vent just make sure the hole is at least 3/4" and goes through any wall into the cellar, so the air can easily escape.


More information needed

@ October 18, 2010 11:26 AM in Some basic questions

Your boiler is slightly undersized but the fact it heats fine during really cold weather tells me that is not the problem. You might want to dial down the venting in the room with the thermostat to get the boiler to run a bit longer and see if that helps things. You also said the third floor gets too hot, have you dialed down the venting on them yet?

You said the Gorton #2 (which never really gets hot on light heating days) appears to be clear and that all is well on really cold days when the boiler has to run longer. How long is each main and are they the same diameter? How many radiators feed off each main? Also can you tell us which radiators feed off what main and how they heat up in relation to each other?

It seems the steam prefers to go towards the Hoffman main rather than the one with the Gorton on it. The Gorton #2 has about 2-1/2 times the venting capacity of the Hoffman 75 so something is up unless the main with the Gorton is much much longer than the Hoffman's main is. Is all the piping pitched back towards the boiler? Use a level, don't just depend on your eyes, If you have water pooling in the pipe that can't find it's way back to the boiler that can cause problems.

I don't think you mentioned anything about your header and hartford loop, if they are not set up properly, the boiler is not going to work as good as it should. Dan's books have plenty of illustrations that show how they are supposed to be set up. Also some pictures of the boiler, near boiler piping, and the mains (and main vents) would make it easier for us to visualize your system.


Radiator not heating fully

@ October 16, 2010 3:01 PM in Steam Rad Not Working?

I assume this is a single pipe steam system - only one pipe feeding the radiator. Put a level on the radiator and make sure it is pitched back towards the input valve and make sure that valve is all the way on.

Is this the last radiator on a main? Your main vent may be to small to vent the air out of the main quickly enough and the radiator vent alone just takes too long. What kind of air valve did you replace and what did you replace it with? You may need a vent that is rated at a higher CFM.

Can you take some pictures of the boiler, the  piping around the boiler, and the basement piping that leads to this radiator? Make sure you show any vents on the mains. Once you have them post them to this site so we can see what your dealing with. Also can you do a simple sketch that shows how the boiler and piping is laid out, showing any main vents and their relative position is to the problem radiator. Then scan that and post it along with the pics.

To determine the right venting you have to find out what the volume of the pipes and the radiators are. Dan's Greening Steam book has all this information and a lot more in it. If you look under the SHOP menu you can find this and other books that are available. The books are a one time cost that will pay for themselves many times over.


run time PDF

@ October 16, 2010 8:48 AM in New Steam owner looking for wisdom

Sorry that pasting of the spreadsheet worked out so poorly, hopefully the administrator will delete that post.

Enclosed please find a PDF version of the page


Burn time data

@ October 16, 2010 8:37 AM in New Steam owner looking for wisdom

The removed kitchen radiator won't have any meaningful impact as long as the capped pipe isn't leaking steam. I pasted the worksheet below so you can see my results. I looked for the data on the progress of the stem through the system but couldn't find it, it may be on my other computer.

Setting the thermostat artificially high will replicate the effect of coming off a night time setback. I set my system back about 4-5 degrees at night but a lot of folks just let run at a constant temperature. BTW I installed a elapsed time meter on my oil burner so I could track the boiler on time; from Jan 11 to Mar 11 my boiler ran for 79.3 hours. At that time I had a 1.25 gal per hour nozzle, that has been changed to a 1.1 gal per hour nozzle so I'll have to see how that works out.

JPF321 - thanks for the heads up on the allowable file attachment types.

The spread sheet has been enclosed in an attachment in the following msg.



@ October 15, 2010 7:32 PM in New Steam owner looking for wisdom

Sorry about the huge type.

Lets see if the file I promised comes through this time.

Pressure and stack temp

@ October 15, 2010 7:29 PM in New Steam owner looking for wisdom

What did the gauge read before it was serviced? Maybe the
work done on the boiler just freed up the needle but those gauges can
get pretty iffy with age. then again JPF321 could be right about the pigtail being cleaned out during the servicing.

The steam pressure will fall pretty quickly because the steam is
condensing on the pipes as it goes down the system till everything gets
hot. Low pressure steam moves pretty quick but takes a while to get all
that iron hot. When I really started to tweak things I'd sit in the
cellar and time the boiler to see how long it took the output pipe to
get steam hot and then how much longer it took for the main vent to get
just as hot. Any time I made a change I'd repeat that to see if I was
going the right way. At this point it takes my boiler about 14 minutes
to shut down on high pressure (mine is set for 1 PSI). Then the system
would condense and the boiler would fire again when the pressure dropped
to 0.3PSI. This goes on till the thermostat is satisfied. If the boiler
wasn't so oversized it would run for longer periods of time and be more
efficient. The system starts at about a minute off and a minute on and
buy the end of the cycle it's 1 min on and 2 minutes off; as I said my
boiler is too damn big. take a look at my runtime spreadsheet that attached.

The stack temperature could have been taken to soon after the boiler was fired up or maybe the instrument was set to read in degrees C instead of F. Do you have a thermometer that will fit into the small hole in the exhaust stack? A meat thermometer would work but don't let the wife catch you.



@ October 15, 2010 1:40 PM in New Steam owner looking for wisdom

4 PSI is too high, it should be 2 PSi or less. Your picture shows the white dial of the pressuretrol set at 2, try turning that down to 1 or less, it really won't turn much lower that one but see how far it goes. Those 0-30 PSI gauges are not very accurate at the low end of the scale and pressuretrols are not known to be precision instruments.

Last year I had to replace my pressuretrol for the second time in 13 years so I bit the bullet and put in a vaporstat and an auxiliary 0-3 PSI gauge so I could see what was going on. I've attached a pic so you can see how it's done, You can see the original 0-30 gauge in the background, it's required by insurance regs. My system now shuts off at 1 PSI.

Don't use the cheap big box air vents, I use Hoffman 1A's (adjustable) but any name brand is better than the junk some stores try to pawn off on you.

I hope that 225 stack temp was a typo, because that's muck too low!


Oversized boiler

@ October 15, 2010 12:46 PM in Boiler Oversizing and Radiator Survey

Welcome to the club.

My boiler was installed in 1996, before I educated myself about steam, and i ended up with a Burnham V75 thats rated at 596 sq ft of steam. The problem is I only have 190 sq ft of EDR connected to it, this is in a 1100 sq ft two story house. I could probably heat the houses on each side of me as well as my house!

Luckily the installer did a pretty good job with the piping, the header is really too low but the hartford loop is spot on. I started out with a 1.5 gal/hr nozzle and over the years I've downsized to a 1.1 gal/hr nozzle. The result is a reasonably quiet steam system that heats everything just fine, although not as efficient as I'd like.

If I had my druthers I'd tear that boiler out and replace it with a much smaller steamer, but it would take forever to justify that on a payback basis. The result is that boiler will do it's job till it dies and then I'll install the right one.

I don't know if your going to have any luck getting the original installer to take that thing out without a court battle, that will take a long time and probably cost you the price of the new smaller boiler. Maybe you could do everything but replace the boiler and see how it works out.

If it were me I'd redo the piping so it meets the manufacturers drawing and I'd make sure it had a nice big drop header on it so the steam would be nice and dry. The piping in the basement should all be insulated and the mains venting should be checked to make sure it is adequate. The steam pressure should be 1.5 PSI or less. All that should quiet everything down although the system would still short cycle and not be as efficient as it could be.  It seems to me that gas burner might be able to be modified so it puts out less heat by getting rid of some of the gas orifices. You can only go so far so be sure your careful with that. It sounds like the guy your working with now knows what he's doing so I'd ask him if this makes sense.

Let me say that I'm not a pro but I've learned a lot over the years by tweaking my system and reading the books that are available under the SHOP heading of this site.

good luck,


low pressure gauge

@ October 14, 2010 6:41 PM in Balancing system part two

I bought a 0-3PSI gauge from this online source, copy and paste the line below into your browser-

You really have to keep the 0-30 gauge to keep your insurance company happy so you will have to see if there is another tapping you can use or add another T so you can mount the new 0-3PSI off the existing siphon loop.

If your going to take things apart you might want to replace the siphon loop (they tend to plug up over the years), just make sure you use a red brass loop not a black iron one (iron plugs up faster). I know McMaster-Carr has them if you can't get one locally.



@ October 14, 2010 9:38 AM in Some basic questions

EDR refers to the square feet of radiation that the boiler feeds. Steam boilers are rated both in BTU's and Square Feet of Steam, find out how many sq ft of steam your boiler is rated for and compare that to the total of all the radiators.

The boiler should be able to supply more square feet of steam than the connected load (15-30% depending on the pickup factor). "The Lost Art of Steam Heating" has some charts that will let you figure how many square feet (EDR) your radiators have. As an example I have 3 column radiators that are 38" high, according to that chart each section is 5 sq ft. The living room radiator has eight sections so 8 x 5 = 40 sq ft for that radiator.

Steam can only heat the radiators if all the air in the system gets out of it's way, steam will not go where air is. That main vent that is just getting warm has probably failed shut. Radiators on that main will take forever to heat up. You really should figure out the volume of the main and select a main air valve that will vent that main in about 2 minutes. "Greening Steam" and the "Balancing Steam Systems" ebook both explain this process. For now just get another Gorton #2 and replace that bad vent, if you end up needing more venting you can add more later.

You mention that shutting off the two radiators on the 3rd floor causes some radiators not to heat as well. that is probably because the mains air is trying to vent out of the individual radiators and when you shut two of them off the venting slows down a lot. Once you replace that vent that situation should change.

Once you get the mains so they fill with steam all the way in a couple of minutes you can see how the radiators are doing, you may find some bad radiator vents on them. i use the Hoffman 1A adjustable vents ( sells them at a good price especially if you buy a six pack), I have tried the cheap Chinese adjustable air valves but I don't really trust them.

Now as to the dirty boiler water, any time you add fresh water to the boiler you have to boil all the oxygen out of the water or it will attack the cast iron. If that boiler has been poorly maintained in the past it will take a lot to get cleaned out. The LWCO port is pretty high up. You should try flushing the boiler from a mud leg (down at the bottom of the boiler) to get more crud out and it might take power washing to get it really clean. For the moment just try and flush as much crap out of the bottom of the boiler as you can.

What pressure is the boiler running at? It should be below 2 PSI and preferably lower. The gauge on your boiler is probably 0-30PSI and seeing 2 PSI is not easy, you might want to add an outboard 3 PSI gauge so you know what the pressure is. If the gauge doesn't move at all it may have failed and then you have no idea what pressure the boiler is running at. The higher the pressure the less efficient the system will be, keep the pressure low.

Once the boiler is relatively clean, the venting straightened out, and the pressure set where it belongs the sight glass might calm down. If not the near boiler piping has to be examined. Post some pictures of the boiler and the near boiler piping so we can see what your dealing with.

I'm just a homeowner but I've lived with steam heat all my life, until I bought and read Dan's books most of what I did was monkey see - monkey do. Those books contain a lot of information, with that knowledge you will understand more than a lot of the people who work on them do because too many of them were never really trained on steam.

good luck,

« 1 ... 84 85 86 87 88 89 »