Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Help me solve this one cold steam radiator puzzle please... See attached detailed diagram

Help me solve this one cold steam radiator puzzle please...

HISTORY
It is a 100 year old house, one steam pipe system with 11 radiators. One zone. All radiators fine except for the red circled one in the graphic attached. I have had the house for 16 years and never checked or replaced the main vents. All radiators have completely open valves, newish vents. All radiators slightly angled down towards the valves. No radiators leak. The house heating is and has been balanced except for the problematic radiator.

But over the last few years the red circled radiator has gotten colder. SEE ATTACHED IMAGE. I even put a varivalve vent on it wide open, but the radiator only half warms up during the big burn in the morning. Not for incremental burns. For incremental burns the insulated steam pipe in the basement to this radiator does not even warm up at all.

I even had a local heating fellow come over and he looked at the situation and told me I had to 'rebalance' the vents across the house. Kinda vague..

WHAT I NOTICED
Well I considered that. But I notice that the radiator for the room the house thermostat is in (orange circle) heats fine with the smallest vent size, about 1/32" !) So there is plenty of steam at that point. But next door, about 15' of insulated steam pipe further, that radiator does not heat.

WHAT I DID
So I disconnected the red circled radiator and flushed 3 gallons of water down the pipe thinking there might be too much crud in the pipe below, but that had no effect. I attached the radiator to the pipe and blew through the vent hole, no restriction there...

Really, I have no idea of how to increase the heat to this radiator. Any ideas?
Brewbeer

Comments

  • Fred
    Fred Member Posts: 8,540
    edited February 2020
    Is there just one riser out of the boiler feeding both mains in opposite directions?
    Having said that, is the run-out (pipe) to the problem radiator pitched back to the Main so that water can drain out of it? If not and it is holding water, the steam may be condensing when it hits the water and before it gets to that radiator.
    ethicalpaulmattmia2
  • Jamie Hall
    Jamie Hall Member Posts: 20,439
    Check the runout to that particular radiator for proper pitch or any sags.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaul
  • Gsmith
    Gsmith Member Posts: 420
    What type vents are on all the other radiators?
  • BobC
    BobC Member Posts: 5,380
    I agree the first order of business is to check all the horizontal piping that feeds that radiator has slope so water can not pool in the pipe, that will kill the steam trying to reach that radiator. If you can remove the insulation on the piping feeding this one radiator. Any belly along that pipe can pool water, make sure there is enough slope. Can you hear any gurgling or boiling sounds along that pipe?

    If all the slopes on that pipe are good and there are no bellies check the input valve to make sure the disk hasn't fallen off and is partially blocking the pipe - this is rare but it can happen.

    What is the total EDR of you radiators and how does the compare with the boiler EDR / SQ FT of steam? If the boiler is able to deliver more steam than the system needs is that boiler firing at the right rate?

    Steam always flows to the point of least resistance, sometimes you have to increase resistance elsewhere to get steam where you want it. What kind and size vents are on all the other radiators? It's possible you may have to lower the venting rates on the other radiators to get steam to this problem radiator.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    What pipe size is the runout leading to the problem radiator?

    Can you feel heat getting to the far end of the runout, before it gets to the riser?
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • mattmia2
    mattmia2 Member Posts: 7,162
    edited February 2020
    I like the idea that for one reason or the other the boiler has been gradually underfiring either because it is getting dirty or an orifice is plugging up or one of the regulators is drifting or something similar and this is the most distant radiator.

    But check for that pipe collecting water first. Are there any drips attached to that run?
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    mattmia2 said:

    I like the idea that for one reason or the other the boiler has been gradually underfiring either because it is getting dirty or an orifice is plugging up or one of the regulators is drifting or something similar and this is the most distant radiator.

    It isn't clear if it's the most distant from the picture, but with long runs, the diameter is also a factor in determining how much air needs to be vented and how much friction there is.

    If this boiler is on residential NG, the service pressure can also affect the firing rate.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • davevarga
    davevarga Member Posts: 44
    Wow! Thank you for all your responses! I am sending one email with sections for each of your questions and considerations.

    Fred and Jamie and mattmia2 and Fred
    The horizontal section under the problematic radiator is slopped towards the boiler. It is not sagging, it has a good pitch. I removed the insulation to determine this and used a level. Not sure what drips are. I hear no gurgling, there is no dripping. You can see from the diagram that the nearest dedicated return is a good distance away.

    Hmm, maybe the boiler is getting dirty..?

    Fred
    Yes, one main riser from the boiler splitting into two pipes, one servicing the front of the house and one for the back.

    Gary Smith
    The vents on the other radiators are mostly Maid O Mist with various vent size inserts. A few VariValves only for two radiators that I need maximum opening.

    Bob C.
    The valve to the problematic radiator is fine. In this process on this particular problematic radiator, I disconnected the radiator and spilled 3 gallons of water down through 1/2" plastic hose into the open valve just in case there was crud in the horizontal section of its feeder pipe. I then reconnected the radiator and with the vent off - blew through the vent hole, no restriction... Which was the same before I dumped water through the valve.

    I do not know about EDR. I can tell you this, except for this one radiator dimming over the years, the heat has been fine throughout this house. There are 11 radiators with a Weil McLean EG-65 with a Net I-B-R of 633 square feet of steam (the manual says).

    I do not think there is too much steam in the system as if there was it would certainly go up the pipe to the problematic radiator.

    As far as lowering the venting rates of the other radiators, please consider the 'next door' orange radiator. It has a Maid O Mist vent on it #4 which is the smallest hole, it must be 1/32" in diameter! And yet this critical radiator gets hot and heats the room where the thermostat is. With that small of a vent hole there has to be good steam in the pipe at that point. And if I lowered the venting rates of the other radiators, I would have to use an even smaller hole for this critical radiator right? Just trying to understand. But again, if that orange radiator has plenty of steam, how come it does not travel up the pipe to the problematic radiator except barely during the first morning burn?

    I can tell you on the ten foot vertical run in the wall up to that radiator, there also is insulation around that pipe.

    Mattmia2
    What do you mean by "maybe an orifice is plugging up or one of the regulators is drifting"

    Hap_Hazzard
    The horizontal pipe to the problematic radiator and then it turns into a vertical - the outside diameter - both are 1 5/8". I note a few other radiators have a final run size of this diameter.

    This horizontal section remains lukewarm for all incremental burns. For the big burn first thing in the morning it heats up and the problematic radiator gets 1/3 warm. That is the only time.

    Best,
    Dave Varga
  • mattmia2
    mattmia2 Member Posts: 7,162
    A drip is a pipe that tees off of a low section of steam main and connects to the return when the piping can't be arranged to all slope to one end or the other to remove the condensate from the steam main. Your diagram doesn't show it, but just wanted to make sure it wasn't showing something.

    If the boiler isn't firing at its full rate it may not be producing enough steam to fill all of the radiators. I was suggesting reasons it might be underfiring. If it is natural gas you can clock the meter to see how much gas the boiler is consuming and compare that to the ratings plate on the boiler:

    https://www.gormanindustries.com/index_htm_files/Clocking Meter.pdf
  • Fred
    Fred Member Posts: 8,540
    edited February 2020
    What is the diameter of the main that that radiator is on? With an EG-65 and only 11 radiators, I suspect you have more boiler than you need and that should not be a problem unless all the radiators are huge. Did you notice this problem at any time something else changed, like putting new, larger main vents on or changing the radiator vents on that main? My other thought is that the main, depending on its size can only carry so much steam and steam will take the path of least resistance which will be to the end of the main where the large vent is. After that, it will start to fill the radiators and again, depending on the size of that main, there just may not be any left as it backs up into that radiator. I would try a smaller orifice on the radiators, on that main, beyond the problem radiator and see if that slows the steam down enough to push steam into the problem radiator.
    As a test, you can close off one or two of the radiators past the problem radiator and see if that radiator heats up.
  • Gsmith
    Gsmith Member Posts: 420
    Are you sure the varivalve on the problem radiator is not plugged? These vent so fast that sometimes they get rust particles blown into them and plug. Try another type of rad vent to see if it makes a difference.
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 7,162
    Or take the vent off altogether for a cycle or 2 and see what happens. If the radiator heats and you get steam at the vent, it is a problem with the vent balance or the vent at that radiator.
    Precaud
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    davevarga said:


    The horizontal pipe to the problematic radiator and then it turns into a vertical - the outside diameter - both are 1 5/8". I note a few other radiators have a final run size of this diameter.

    This horizontal section remains lukewarm for all incremental burns. For the big burn first thing in the morning it heats up and the problematic radiator gets 1/3 warm. That is the only time.

    So that sounds like a 1¼" runout. Do you know how long it is?

    I suspect this is just a case where you need a lot more venting than usual, because the radiator gets hot on extended runs, but the far end of the runout barely gets warm on shorter runs. I bet if you felt that runout during the morning run, it would be about the same temperature at the time where the boiler would be shutting down on a short run, then keeps getting hotter. @mattmia2's suggestion would confirm this. If you remove the vent and still don't get steam by the end of a normal cycle, there must some kind of obstruction. If it does get steam, we just need to figure out how to put a big mouth or Gorton #2 on that sucker. :D
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    BTW, the difference between 1" pipe and 1¼" might not seem like a lot, but the cross-sectional area is 73% greater, so the same length of pipe would hold 73% more air and would require 73% more time to vent at the same rate.

    All of the second floor radiators in my house are on 1" branches, and the first floor radiators are on 1¼", regardless of how big they are. The dead men wanted to make sure the upstairs radiators wouldn't take too long to get steam. I still had to use the full range of vent sizes to balance them, but they all get hot.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • AMservices
    AMservices Member Posts: 605
    @davevarga , are you tracking how much water your boiler uses?
    Or how often do you add water?
    If the radiator used to heat, then something has changed about the system.
    Did the problem get worse after other vents were replaced?
    Are all the radiator vents screwed in tight, or are some loosely attached?
    Have any of the other radiators been disconnected and put back?
    Steam is always looking for the easy way out. Any leak around a packing nut or loose threads around an air vent will throw off the balance.
    Steam leaks are hard to find because it leaks out as vapor into the air. Even if condensate drips out, it usually vaporizes before it hits the floor. So you need to put your detective hat on and look carefully around the system for evidence of water damage, rusty marks or corrosion.
    Hap_Hazzard
  • dopey27177
    dopey27177 Member Posts: 885
    The problem radiator seems to have a very long lateral run of pipe.

    The run out may be undersized or back pitched. Depending on how long the run out is it may be expensive to increase the size of the pipe one pipe size up to the vertical supply to the radiator.

    An economical repair would be to remove the elbow at the vertical rise and install at "T". Drop a 3/4" copper return to the floor and then pipe to the boiler with a new wet return.

    See the pages 190 and 191 for connections to one pipe radiators.

    If the problem is because of undersized pipe you can evaluate which solution is most economical.

    Jake


  • mattmia2
    mattmia2 Member Posts: 7,162
    The key here is to think of which causes could have become progressively worse over a few years.
  • davevarga
    davevarga Member Posts: 44
    BobC!
    OK! From your idea I went back with a flashlight and took off the radiator and closely looked at the "disk" in the valve. Not sure which portion is the disk, all of it or a portion of it, but look at this combo picture. On the problematic radiator it looks like the disk is there but compared to the operational radiator the washer/spacer thing underneath it is missing, is this what you refer to as the disk? If so, it could have fallen off and it could be that it is partially blocking the pipe below?




    MATTMIA2
    The returns are as shown in the diagram, I did not miss any.

    FRED
    I never changed the 3 main vents since I have been here for 16 years. Nothing else really changed, I keep swapping out vents if they go bad and replace them with same adjustable vents with the same size vent opening. The only thing changing is that one radiator dimming over time to being completely cold during incremental burns, even the dedicated horizontal pipe underneath at these times remains room temperature.

    The feeder pipe out of the boiler is 3.5" outside diameter, it rises and branches into the two smaller pipes.

    Notice on the diagram there are two large Gorton #2 main vents and one small Gorton #1 vent.

    GARY SMITH
    Yes I am sure the varivalve on this radiator is working, I just checked. And then I replaced it anyway, also leaving it fully open.

    HAP HAZARD
    Tried it with no vent. No difference. The varivalve vent fully open is basically the same as not having a vent at all.

    AMservices
    During the winter I check the boiler water level at least twice a day. I probably add some water once a week, bring the water level up .5".

    All radiator vents are screwed in tight, no radiator is leaking, I checked.
  • mattmia2
    mattmia2 Member Posts: 7,162
    edited February 2020
    That looks like the washer fell off and is stuck in the seat blocking it. you will have to take the stem out of the valve to replace it.

    It looks like the whole top half of that valve unscrews with the stem and threads.
  • BobC
    BobC Member Posts: 5,380
    can you get a wire into the valve to probe for anything sitting lower in that valve / feed pipe. What you see could just be the screw that holds the rubber disk backing off.

    I would take that valve apart to be sure the pipe isn't being partially blocked by a detached rubber disk and to try and snug up that screw holding the disk in place.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • davevarga
    davevarga Member Posts: 44
    edited February 2020
    Mattmia2
    See attachment, enhanced detail where the horizontal pipe meets the main pipes, it probably is what you are asking about.

    Mattmia and Bob C

    I'm thinking of:
    (1) disconnecting two good radiators so I can get good airflow through the system in prep for the next step. Then disconnecting the problem radiator. with tape and getting a good seal, attach a good size wetvac to that valve and turn the WV on and suck up anything that fell right below the valve or if it fell down the valve.

    And first cleaning out the wet vac so if anything does comes up from the problematic pipe, I can identify it when I turn off the WV and examine the contents.

    What do you think about this.?

    (2) And if that does not work, get a 25 long drain snake with a half inch or 5/8 inch diameter end piece, and snake it down the problematic pipe all the way to where the pipe meets the main pipe. Then pull it out. Then quickly insert 3-4 gallons of water in that pipe via a hose and a funnel. This all to break up and loosen any broken pieces from the valve that might have fallen down there, and then flush it down to the large pipe.

    What do you think about this?
  • Fred
    Fred Member Posts: 8,540
    Do you have an Inspection camera like the Milwaukee or similar, with a 2ft or 30 inch cable on it? That would allow you to see anything that might be near the valve, maybe even to the first elbow on the supply pipe.
  • AMservices
    AMservices Member Posts: 605
    How long has it been since your boiler has gotten a good cleaning? I mean really flushed out.
    I'm looking at your drawing and how the problem radiator comes off right after the main makes that drop around the corner.
    If the boiler is dirty, it will produce wet steam. And wet steam is a lot of water flying around the piping with the steam.
    Sometimes the water can be making waves in just the right way that it will cut off steam to this line but not that line next to it.
    That's something that will get worse over time.
    Heat it up then Drain down the entire boiler block, re fill and do it again. As many times as it takes to get the water clean.
    Can't hurt.
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 7,162
    I'm thinking if you take the top of the valve off that the washer is right in the valve and impeding steam flow and/or condensate return. judging from the paint it hasn't been opened up in many decades.
  • mattmia2
    mattmia2 Member Posts: 7,162
    It is hard to tell from your pictures and with the paint, but I think your globe valve is this type where the bonnet unscrews from the valve body to repair the washer. If you unscrew the bonnet I think you will find pieces of the washer inside (or maybe in the spud in the radiator).

    https://upload.wikimedia.org/wikipedia/commons/thumb/e/e5/Globe_valve_diagram.svg/220px-Globe_valve_diagram.svg.png
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    That valve is the type with a metal shell around the disc, and it looks like the disc material has fallen out, probably in pieces. Chances are the pieces have fallen right down the riser and are stuck in the elbow at the bottom. If you remove the valve from the riser and remove the main vent and any reducing bushings you can from the end of the main to let some airflow in, there's a chance you might be able to suck them out with a shop vac. If that doesn't work, try flushing them out the other way with a hose. If neither approach works, you'll need to do some dismantling this summer.

    I'm not totally convinced that that amount of debris would create enough of an obstruction to keep the radiator from getting hot, but it fits the description of "something that may have changed recently."

    ¯\_(ツ)_/¯
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
    mattmia2
  • mattmia2
    mattmia2 Member Posts: 7,162

    That valve is the type with a metal shell around the disc, and it looks like the disc material has fallen out, probably in pieces. Chances are the pieces have fallen right down the riser and are stuck in the elbow at the bottom. If you remove the valve from the riser and remove the main vent and any reducing bushings you can from the end of the main to let some airflow in, there's a chance you might be able to suck them out with a shop vac. If that doesn't work, try flushing them out the other way with a hose. If neither approach works, you'll need to do some dismantling this summer.

    I'm not totally convinced that that amount of debris would create enough of an obstruction to keep the radiator from getting hot, but it fits the description of "something that may have changed recently."

    ¯\_(ツ)_/¯

    Unless it fell out in more or less one piece and is sitting in the valve body somewhere.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    In the only valve of that type that I've seen, the disc broke up and fell out piecemeal. A few pieces were still clinging inside the shell. As far as I can tell, the pieces that fell out never caused any problems. I assume they eventually got washed into the return. That's definitely not a significan sample size, so YMMV.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • davevarga
    davevarga Member Posts: 44
    FRED
    No inspection camera do I have

    AMservices
    One or two minor cleanings in the last 15 years. I will get the boiler cleaned.

    Mattmia2
    Thank you for that about the shop vac. I made an interface between the wetvac and the valve that I will get a tight seal for max suction.

    ALL
    This Saturday I will disconnect two radiators upstairs and leave their valves open so the wetvac can pull air quickly through the problematic radiator on the floor below, Then
    (1) suction the problematic valve (and pipe) with a wetvac. Then look at the interior of the wetvac for debris. Maybe I will be lucky. Then probably
    (2) Use a 25-FT Steel Drum Auger Plumbing Snake with a 3/8 head on it, 25' long and go the length of this segment of this steam pipe. I will do a quick and light treatment and then pulll up the snake.
    (3) Reattach the wet vac. Suction the pipe. Turn it off, look at the debris in the wetvac.
    (4) Flush 3 gallons of water down the pipe to move any crud to the big pipe.

    Sunday clean out the boiler itself.
  • Fred
    Fred Member Posts: 8,540
    @davevarga , there is no reason to disconnect two radiators and risk them leaking when you reconnect them. Your steam system is open to the atmosphere when it is not running. All vents are open, Main vents are open and all pi9pes are filled with air. Plenty air to suction with the wet vac.
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,787
    I don't think the vents alone will allow enough air flow to suck something up a third floor riser. Besides, I disconnect radiators all the time to clean or paint behind them.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Fred
    Fred Member Posts: 8,540
    edited February 2020
    If it's the disc, it has to be in the immediate area of the valve, otherwise it wouldn't likely cause a blockage at that radiator and, if it got past that immediate area, the diameter isn't large enough to block a 1.25" or larger riser and too big to fall into a 1" riser. It's not like it has to be sucked up three floors. If there is an elbow a few feet under the floor, it might be there. If the first elbow is in the basement, I guess it could be there but my guess is it never got past the base of the valve itself.
  • davevarga
    davevarga Member Posts: 44
    edited March 2020
    Solved!Thank you everyone for your help!
    With the wetvac and then routing out the pipe to the problematic radiator and then pouring 4 gallons of water down through that valve, that solved the problem thank you everyone for your help. The radiator heats relatively normally now.
    And I will flush out the boiler next anyway.
    Hap_Hazzardmattmia2
  • BobC
    BobC Member Posts: 5,380
    I'm glad you solved this. Solutions are not always apparent but with perseverance you can find the way.

    Bob
    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge