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Steam Radiator Problem

Hi Everyone.

I recently moved into a home with a combination hot water/steam heating system.  There is hot water baseboard on the first floor and steam radiators on the second floor and the third floor (converted attic). 

I recently had the boiler cleaned.  The first floor baseboard heating is working fine.  However, only two of six radiators are working.  Two radiators (in the same room) on the second floor are working.  The radiator on the third floor is working.  However, the other three radiators are stone cold.  I recently replaced all of the air vents but that hasn't helped.  Any suggestions?  Thanks.


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,575
    stone cold rads

    is this 1-pipe steam or 2-pipe? by replacing the vents, are you referring to the main air vents, which do all the work?

    if those main vents are new, and very ample; then you may have an over-pressure problem. this may be caused by a clogged pigtail, not allowing the pressuretrol to "feel"  the pressure. check to see that you are at or below 1PSI. if you have trouble reading the standard gauge, then i would suggest getting a good low pressure gauge [gaugestore.com 0-2 PSI].

    the other thing to check, would be the pitch of the steam pipes leading to the troubled area. if there is a low spot in the pipe, the air will not be able to escape through the main vents [not rad vents], and so no steam can rise up to the rads.

    i would suggest you get the "bible" of steam heating here, so you can be more able to diagnose problems as they arise--"the lost art of steam heating".--nbc
  • Yanks2009
    Yanks2009 Member Posts: 20
    stone cold rads

    Thanks for responding. 

    The system is a 1 pipe system.  By vents, I was referring to the air valves (maid-o-mist, etc.).  I feel some air venting from the air valves of the radiators that aren't working.  Because they're stone cold, it seems like the steam isn't even reaching them. 

    Here is a link to some pictures of my heating system (not sure if this is helpful or not): [u][color=#800080]http://s967.photobucket.com/albums/ae155/nyyanks2009/?[/color][/u]

    I have ordered the book which should be very helpful considering I know very little about heating systems. 

  • Unknown
    edited October 2009
    Boiler Piping

    After looking at you pictures it would appear that you have some serious issues with your boiler piping as it is very "unconventional".  We could tell more if you could take some other pictures of the boiler piping standing farther away from the boiler that way we can get a better over all view. With the resolution today it is easy to then blow up if one needs to look at more detail. Take pictures of the piping from all sides.

    Glad to hear you ordered "the book" besides "The Lost art...."  I'd also get  "We Got Steam Heat" as it is a good overall introduction which "The Lost Art ..." then continues on. Easy reading and in an evening or two you'll know a lot more about steam heating.

    You might want to take a look at the  "Find a Professional" at the top of this page and see if there is a steam pro near you.  The fix is fairly simple but requires some repiping by someone who knows what they are doing.

    Let us know the make & model of your boiler. I couldn't read the plate info in the picture.

    - Rod
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,575

    i think that you really need main vents, as the capacity of the radiator vents is only large enough to handle the air in the riser and radiator, when you are on a short "burn" in moderate weather. usually these main vents are on the dry return  just before it drops down to the wet return on the way back to the boiler. 

    also check the steam lines leading to the cold rads for a "sag" in which could form a pond of water, blocking the air from getting out. use a level, and put tape on the pipes with arrows indicating direction of downward pitch. if you see arrows pointing towards each other, then you know you have a low spot!--nbc  
  • Yanks2009
    Yanks2009 Member Posts: 20
    edited October 2009
    Boiler Info

    Thanks for the informative posts.  I will take more pictures.  It's kind of hard to get a good picture of all the piping because there is actually a closet (made up of ventilated panels) surrounding the boiler, but I will try.

    The boiler is a Crane 200 series model.  I think it has to be 35-40 years old. When I had the boiler serviced the technician commented that the boiler appeared to be pretty clean.  The prior owner would drain it (at least from the low water cut-off) every week.  Aside from the problems with the rads, the boiler seems to be working fine.  Not sure about efficiency, my first heating bills should be interesting.
  • Explore your Steam System

    I remember reading somewhere that Crane stoped building those boilers in about 1973. So your boiler is probably around 35+ years old.

    I think what I'd do while I was waiting for the steam books is to survey your steam system. Trace the pipes coming out of the top of the boiler and where they go and what radiators are likely to be attached to them.  The piping basically goes in a loop, it rises from you boiler to the horizontal piping (called the mains and continues along with lateral pipes coming off it (the main) to the radiators. At the end of the main there should (maybe) be a "main vent"   This is attached to the top of the pipe and  will look either`like a can of tuna on its side or a large bullet shaped object (maybe chromed) facing point up. At the end of the main the size of the pipe will probably decrease and the pipe (now called the dry return) will head back to the boiler. Just before this pipe turns from the ceiling down to the floor, there maybe a main vent attached here. (this is an alternate location for main vents)  At the point the dry return drops below the waterline of the boiler it changes name and is now called the "wet return" (even though it is the same piece of pipe).

    That describes  a basic single steam loop from you boiler. Most houses have several of "loops".  What I would do is draw out a quick sketch of your  floor plan with the loop piping and where the radiators, main vents attach/are located  and then as you read the steam books you'll be better able to relate to your system.

    With the books things will fall in place quickly for you and then we can what areas you are having problems with.

    - Rod

    - Rod
  • Yanks2009
    Yanks2009 Member Posts: 20
    Too much water

    Thanks Rod. 

    I think I may have figured out the problem (hopefully).  I noticed some water leaking from a wall in my basement.  I traced the mains from the boiler and sure enough the leaking was caused by spitting from the main vents. 

    I had my boiler serviced a couple of weeks ago and I think that the technician added too much water.  The sight glass was completely full.  I have drained some water from the boiler to bring the sight glass down to the 1/2 to 3/4 level. 

    I noticed that the main vents are very old, especially the one that was spitting the most water (made by a company called "travallar"). Do you think the main vents should be replaced, or should I first try running the system now that I've drained some water?  If so, do you know of a good place to order them.  My local home depot and lowes only carry 1/8" vents for radiators.  The openings on these vents are larger (at least 1/4").  Thanks.
  • Vents

    Do you have any paper work with your boiler like an owners manual?   The water level for your boiler when its cold (not operating)  should be about 1/2 way up the sight glass.

    (2/3 is fine 3/4 might be a little bit high but okay.)  After the boiler has been operating (making steam in the heating cycle) a while, the water level will drop down but will still be visible in the glass. Is there any mark on the glass tube or cabinet under the glass tube showing where the water line should be? We can discuss this more when you get the books as there are diagrams I can refer you to.

    Main vents - These are special vents which Home Depot etc isn't like to have.   You need to measure the length of your mains and the pipe sizes and we can figure the volume capacity ,then tell you what you need in venting. I've attached a chart which will help you figuring your pipe sizes.

    Main vents, being mechanical and having moving parts, are usually only good for a couple of years though many go on far beyond that. You  just need to check them occasionally to see that they are operating okay.

    You might want to read this thread as there is some good discussion on main vents


    Most people use Gorton vents and are getting them from Pex Supply on the internet.

    Gorton Main vents are Model  #1 & Model #2  A Gorton #2 has about 3 times the venting capability as a Gorton #1.  On the thread above "Menorahs & Antlers" were discussed. This is a good way to set up a main venting as it is easy to add to the venting if you feel you need more vents.  Using a pipe union is a good idea (see drawing in post) as it allows you to make just one connectiong while standing on a ladder among the floor joists.  If it were me I'd start with a Gorton # 2 on the end of each main.  Check the clearance between the ceiling an the top of the main as lack of space can sometimes be a problem.  You can under vent though it is almost impossible to over vent.

    BTW- On another subject- If you add new water (fresh water) to your boiler, always then bring the new water in the boiler to the boil (make steam) as this drives off the excess dissolved oxygen in the "new" water. Excess oxygen can be very corrosive and is the major reason for premature boiler failure.

    - Rod
  • Yanks2009
    Yanks2009 Member Posts: 20
    water level

    Thanks for the advice.

    I will measure the mains and the pipe size.

    I drained water from the boiler so that the sight glass was half full.  However, it seems as though the low water cut-off added more water, so now the sight glass is again almost full.  Any suggestions for regulating the amount of water in the boiler?

  • Water level

    Hi - Let's not worry about the sight glass water level at this point. I took another look at your pictures and your boiler seems to have a shorter sight glass than other boilers so maybe where the level is could be considered normal. (This is where having the boiler's manual comes in handy!) You say the boiler is full. When the boiler is cold, can you see the "full" water level on the sight glass or is the water level above where you can see it?  When the boiler is operating where is the water level?

    I'm trying to get a mental picture of your system. You mentioned having  a "hot water baseboard on the first floor". What is the source of the "hot water"?   LOL I know you immediately thinking, "Duh, the boiler, Dummy!" , but what I'm wondering is does it have a separate set of pipes going to the boiler? If so, is there a  pump somewhere (should be close to the boiler ) on these pipes?  Look at the piping to this radiator and find out where comes from and where it leads.

    I'm still a bit lost on the location of the "cold" radiators,  You have three floors, where are the cold radiators located? Now that you've had a chance to survey your system a bit does it look like these radiators are in the same side (section)  of house and are possibly connected to the main with the bad (leaky ) vent?

    Were you able to find the  source for Gorton vents on the internet?

    - Rod
  • Yanks2009
    Yanks2009 Member Posts: 20
    water level

    Hi Rod.

    I received the Lost Art of Steam Heating book today. I'm looking forward to educating myself on steam systems.

    Unfortunately, the prior owner did not leave a manual to the boiler.  As the boiler is old and no longer produced, I do not know where I'd find a copy of the manual.

    The sight glass was full to the point that I couldn't see the water line, both when the boiler was off and running.  I have not yet run the boiler to test it after emptying some water (it's been quite warm here in New Jersey).  I probably should just run it anyway to see how it's working. 

    I will look at the boiler again.  It seems as though there is a steam pipe in the middle of the boiler and smaller copper pipes coming from the boiler. 

    The radiators in one bedroom located on the second floor on right side of the house (facing the house) get hot.  The radiator in the second bedroom on the second floor also on the right side of the house (but behind the first bedroom, towards the back of the house) was not warming up but finally did after I pitched the radiator.  The radiators in the third bedroom and bathroom (both on the second floor, on the left side of the house) never got warm.  While all of my main vents leaked, the one that was really leaky is also on the left side of the house (underneath the two radiators that aren't working). 

    The radiator in the attic, which is in the middle of the house above the boiler has consistently been working. 

    I think I will use the website you mentioned earlier to purchase the vents.  I emailed Gorton and asked them about local stores that would carry the main vents b/c they're located about 30 min from where I live but have not heard back.

    One main vent appears to be a Gorton No 1.  The really leaky main vent is really old and made by a company called Travallar.  It is also rather small (maybe a 1/4 or 3/8 thread). 

    I still need to determine the size of the last vent (it's in a hard to reach location but I will get back there tonight). 

    If the opening in the main is large enough to accomodate a Gorton No. 1, how can I modify it to fit a Gorton #2, which has a smaller nipple?

    Maybe this is where the antler would come in.

  • Water Levels

    Hi- Great to hear`you received  "The Lost Art..." !   Read`Chapter 13 as it talks about water levels and automatic feeders etc..

    It sounds as though your automatic water feeder is on the blink. I looked at your pictures again and in the one attached there is a label. (marked with yellow arrow)  On that label there also appear to be some writing though I can't read it other than "Operating Water Line" . This should be as low as your boiler water goes during normal operation. If the water drops lower than this point the Low Water Cut Off ( the black gizmo in the picture with the bronze ball valve to drain it ) should stop the burner.  I marked approximately where I would guess  the normal cold boiler waterline should be with a Green Arrow.

    I can't see in any of your pictures an automatic water feeder, so not knowing the type can't give you any info on that.  There is a negative side to automatic water feeders as they can flood your house out if they go bad.  With this in mind some people just feed water to their boiler by hand. Normally you should only need to add a slight amount of water every couple of weeks usually to just make up the amount you blow off weekly testing the Low Water Cut Off.   If one uses an automatic water feeder, it is recommended that you use feeder that keeps track (counts) of how much water is replaced. That way you know what is normal and what is an irregular amount which tells you your steam system has sprung a leak.  Here's a link to the unit a lot of people use:


    It maybe in that your boiler water level being high is causing most of your problems as it is flooding the pipes. This isn't good for your vents and will wipe them out if it has been going on for some time.  You should be able to shut off your automatic feeder`and there should be a bypass plumbed in so that you can feed the water by hand if need be. You might want to do this then you could drain your boiler's water level down to where it should be (water line boiler cold) and turn the burner on and observe the boiler's operation for a while.  The water shouldn't drop below the marked Operating water level during the period it is operating. Also observe how much the waterline "bounces" when the boiler is operating. (3/4 of an inch is about normal)

    On the Gorton Vents try the supplier I mentioned. They are a major supplier and carry  Gortons.  I'd do the fixing while the weather is warm as it's not much fun to work on boilers when it's freezing and you're under pressure to get it fixed !

    - Rod
  • Yanks2009
    Yanks2009 Member Posts: 20
    additional pictures

    It's been a little while since I last posted. I ran my boiler last night after draining enough water so that the sight glass was about 1/3 full. All of my radiators got hot and the heating seems to be working pretty well.

    One cause for concern is that water level keeps increasing. The sight glass is almost full even though I didn't add any water. Could there be a problem with my auto fill? I have included some additional pictures of my boiler, including the auto fill:


  • Unknown
    edited October 2009
    High Water levels

    Possible sources of water - There are several possibilities and as I can't quite figure out the plumbing configuration from the pictures I'll list them and you can eliminate them.

    1. The first is the automatic waterfeeder may be the problem.

    2. If you have a hot water coil that goes into the boiler for making domestic hot water. This may have a pin hole and is leaking water into the boiler.

    3. I haven't figured out yet your hot water heating . Is there a chance water  from this is leaking into the boiler? Is this line connected in anyway to the house water?

    Test for a problem with #2/#3 -  If there is a # 2 or a #3 the first thing to do is shut off the water to the automatic waterfeeder and drain the water level to the "cold boiler water level. Don't operate the boiler during this test.. If the water level rises then the problem is with  #2 or #3.

    If #2 and #3 are eliminated as the source of the problem we then need to turn to the automatic water feeder. There are two possibilities that i can think of:

    A. The automatic feeder is out of adjustment or bad valve.

    B. Something else is wrong and the automatic feeder is just doing its job.


    Let's take "A" first. Do you know when the extra water gets added to the boiler?

    Try draining it down to the cold boiler water`level (make sure you've turned the water back on after testing #2 and #3 above! ) and without turning on the burner, see if the water level rises.  If the water doesn't rise that means the water isn't leaking past the feeder valve.

    At this point we should probably consider "B".   What maybe happening is this. With the boiler water level in the "cold boiler level", the burner starts and makes steam.by boiling the "ORIGINAL WATER " in the boiler. The steam then travels to the radiators and condenses and then begins to flow back to the boiler. However  the condensate finds that its passage is slowed down  by a partially plugged return line so it can't return to the boiler as quickly as normal.

    The boiler in the mean time is making steam like crazy and the level of the remaining "ORIGINAL WATER" in the boiler is dropping and none of the "ORIGINAL WATER" condensate has returned to the boiler as yet The automatic water feeder sensing the need for water does its job and supplies "NEW" water to the boiler. The boiler keeps on making steam until it shuts off.  At this point all the "ORIGINAL WATER" is in the system plus the "NEW WATER". When these two finally drain to back to the boiler, the water level is obviously going to be much higher than the "cold boiler level" when the boiler started.  I hope this all makes sense.

    What you need to do is to closely monitor the boiler through a cycle or

    two and see if the above scenario is going on. Time your boiler's

    operation and how long it takes for the water`level to return to normal

    cold level (or above) after the burner has stopped. This should give

    you an idea of how badly things are plugged up.

    As most crud and muck collect at the lowest part of the system, which is the wet return, this is most likely area to be partially plugged so you'll need to check the wet return and clean it if necessary. Sometimes it just easier to go ahead and replace it. (The wet return  can be done in copper as it doesn't carry steam) Let us know what you find out.

    Edit: Just read a thread on the main board of a guy with the same problem.Thought it might be of interest to you -


    - Rod
This discussion has been closed.