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.

Rads vent for a really long time

Hello, I just replaced all my radiator vents with gorton's and followed their chart for sizing.

The main has a gorton 1 (which was previously installed, but I put a new one in anyway)

It's a classic cape cod house with 7 radiators total. (There's a stairway the splits two upstairs bedrooms) The boiler is in the basement on one side of the house. There's one main and it's a one pipe system.

My question is: what is causing some of my radiators to vent for so long, so loudly?

Also probably worth mentioning is that my low water cutoff has an intermittent test function that cuts the burner off for about a minute every once in a while and then starts it back up. This seems to make the rads vent all over again too.

Comments

  • dabrakeman
    dabrakeman Member Posts: 538
    The radiators are going to vent air as long as the boiler is running and the radiator has not filled to the point of steam closing the vent. If it is venting noisily then they may just be venting too fast. IF you just have a single Gorton #1 on the main vent I would suggest first adding your old (presumably good and functioning) Gorton #1 on an antler so you have the two both venting the main. This may reduce some of the total time the radiators are venting. The other thing to try would be to slow down the venting at the radiators.
    cross_skier
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    edited March 2021
    A Gorton #1 is a pretty small main vent, so I would add a #2.
    Every time the LWCO shuts the burner down, air will rush back into the system to relieve the vacuum. When it fires back up again, that air needs to be pushed out. With this shorter cycling, the main venting becomes even more important, but when completed will yield shorter burn times.
    Don’t follow the Gorton advice, but instead start with generous main venting, and small radiator vents. After a while, any slow rads might need increased venting. A low pressure gauge, (0-3 psi), will aid in monitoring, and keeping the back pressure low (under 2 ounces) in the venting phase.—NBC
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    Even though the burner is off for 90 seconds ( CG400-1090) the boiler remains pretty hot and can continue to generate steam at a slower rate. I am not sure the system would go from pressure to vacuum in that time span. I like the intermittent level test because it reduces any overpressure, thus minimizing the number of times the pressuretrol would short cycle the boiler.

    Has anyone actually measured whether it really happens?
  • Jamie Hall
    Jamie Hall Member Posts: 23,168
    My only observation on pressure drop when a boiler shuts off is based on watching what happens to Cedric when he goes off on pressure (7 ounces) -- which rarely happens. When he goes off, the post purge kicks in -- 15 seconds. By that time the system is down to just a smidge over 0 -- less than 1 ounce. Then there is the pre-purge, another 15 seconds -- and by that time the system pressure is flat zero. It never goes to vacuum, as the vent never closes -- never closes on heating, either, for that matter. Now admittedly that's not one pipe -- it's a big vapour system.

    On a one pipe system, the cycling on pressure or on the Cyclegard contraption actually may have an advantage, in that it lets the vents regain control of the heating rate of the radiators. There's been some discussion about that...

    If the OP's vents are noisy, though, the very first thing I would look at is main venting -- as @nicholas bonham-carter mentioned -- and cutout pressure. There may not be enough main venting to keep the initial fill pressure low enough (certainly not over a pound -- better half a pound or less at the boiler) and the cutout pressure may be too high anyway.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • theONEendONLY
    theONEendONLY Member Posts: 51
    I've never seen the pressure at the boiler over .5 psi
  • neilc
    neilc Member Posts: 2,689
    edited March 2021
    is the gage after the pigtail with the Ptrol(#1)?
    or separate(#2)?
    if #1, and the pigtail is clogged, the gage wouldn't display correct pressure any better than the Ptrol would see it,

    what do you have for main venting?

    pictures , , ,
    known to beat dead horses
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    I should have mentioned above in my post about the intermittent level test function that I was assuming an oversize boiler, which seems to be a common situation.
  • theONEendONLY
    theONEendONLY Member Posts: 51



  • theONEendONLY
    theONEendONLY Member Posts: 51
    Pics attached of pigtail and gorton #1 main vent setup
  • Danny Scully
    Danny Scully Member Posts: 1,416
    It would appear you have a counterflow system...in which case that main vent is doing next to nothing. It may be causing your radiator vents to over work. I’d look into installing a main vent in the proper location. 
    ethicalpaulwlganncross_skier
  • theONEendONLY
    theONEendONLY Member Posts: 51
    edited March 2021
    @Danny Scully here's a few more pics. Do you think the vent is in the wrong location? Where is it supposed to go?
  • KC_Jones
    KC_Jones Member Posts: 5,722
    The main vent is supposed to go at the end of the main near the last radiator takeoff. Yours is on the drip for the counter flow main and is most likely closing right after the boiler starts producing steam.

    Also, how long and what diameter is your main? Unless it's really short, that vent may not be enough.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    cross_skier
  • theONEendONLY
    theONEendONLY Member Posts: 51
    @KC_Jones welp. I just found a vent at the end of the main buried under insulation. Looks like a gorton.

    My main is 2" and about 31' long. Just measured.

    This buried gorton looks horrible. Would I be okay with a gorton 1 over there? Is that enough venting? And what's the point of the one by the wet return then?
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    Since you have the Gorton #1 try that. You can time how long it takes steam to get there on a call for heat, it will probably be fine. Like around a couple minutes after steam production starts 
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • Grallert
    Grallert Member Posts: 643
    Also you have no real idea what pressure your boiler is operating to. Those gauges are very inaccurate and you pressure limit is set why too high.
    Miss Hall's School service mechanic, greenhouse manager,teacher and dog walker
    ethicalpaulDeltat210
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    I would put a Gorton 2 at the end of main location, since your LWCO is cycling the burner; and yes, dial down the pressuretrol, and verify with a proper low pressure gauge.--NBC
  • theONEendONLY
    theONEendONLY Member Posts: 51
    Should I keep that brand new gorton 1 at the wet return or is it not even necessary?

    Thanks for all the replies guys. This has been very helpful.
  • KC_Jones
    KC_Jones Member Posts: 5,722
    The Gorton #1 you have there is not benefitting you and could be slightly hurting you. I'd pull it and plug the hole.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    cross_skier
  • theONEendONLY
    theONEendONLY Member Posts: 51
    @KC_Jones Then I'll plug it and move the brand new gorton 1 to the end of the main and see how it does...

    If I'm still noticing weird venting at the radiators I guess I'll have to bite the bullet and pay $100 for a gorton 2 :-)
  • theONEendONLY
    theONEendONLY Member Posts: 51
    After doing some more reading on this forum I'm seeing that I should have my cut in at .5 and the differential wheel at 1. Is this a good strategy for my setup?
    ethicalpaul
  • bburd
    bburd Member Posts: 909
    edited March 2021
    @op Yes. Those are the standard settings for low pressure steam heat.

    When you adjust the cut-in, be careful that you don’t go too low and cause the mechanism to separate.

    Your existing 0 to 30 pound gauge may not register any pressure once you have done this. They are notoriously inaccurate at low readings.

    Another common problem is for the pigtail between the boiler and the pressuretrol to clog up, causing the pressuretrol and/or gauge not to sense the actual pressure. It can be removed and cleaned out.

    Bburd
    ethicalpaul
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,453
    As @Danny Scully and others have mentioned the vent near the boiler is totally useless. Plug it and add vents to the end of the mains.

    I think you will notice a big improvement
    ethicalpaul
  • theONEendONLY
    theONEendONLY Member Posts: 51
    Got it. Adjusting now, and I will check for clogs. Any gauge with a smaller maximum on the psi will do?
  • bburd
    bburd Member Posts: 909
    edited March 2021
    Regarding a low pressure gauge, most people here use 0 to 3 or 0 to 5 pounds. This must be installed in addition to the code required 30 pound gauge.

    Good practice is to install a ball valve below the gauge, so it can be isolated when not in use. This guards against ruining the gauge should there be an overpressure incident.

    Bburd
  • theONEendONLY
    theONEendONLY Member Posts: 51
    Great. Thank you for all of the advice!

    I'll do my research and order a 0-3 or 0-5 and a ball valve tonight with the proper fittings.

    Also my next step is to cap where the useless gorton 1 vent is and Use it to replace the old rotted one I found buried in the ceiling.
    ethicalpaul
  • bburd
    bburd Member Posts: 909
    If you use brass fittings and pipe to fit your new gauge, clogging will be much less likely.

    Bburd
    ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    edited March 2021
    Even though the burner is off for 90 seconds ( CG400-1090) the boiler remains pretty hot and can continue to generate steam at a slower rate. I am not sure the system would go from pressure to vacuum in that time span. I like the intermittent level test because it reduces any overpressure, thus minimizing the number of times the pressuretrol would short cycle the boiler. Has anyone actually measured whether it really happens?
    Coincidentally I just recorded this. Note that mine is a 1560 so it checks for 60 seconds every 15 minutes

    https://youtu.be/yxKhRCJrtVU
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • JUGHNE
    JUGHNE Member Posts: 11,042
    If you still have the old vent you replaced with the new G1, you could put both on the end of the main using a tee and nipples etc.
    ethicalpaulcross_skier
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    @ethicalpaul Good video. I wonder if the same would happen with a starting pressure higher than 0.6 inches of water.
    ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    Yours does that right?
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    @ethicalpaul I don't have a low pressure gauge permanently installed, so I could not see pressure turning to vacuum. Maybe I'll spring for a Magnehelic just to find out.

    Which pressure-vacuum model would you recommend?
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    I have a more typical 0-3psi gauge on my boiler, those are good. If you are interested in vacuum, then look for a -3 to 0 to 3 type where the gauge rests at 0 in the middle of the range.

    I also have several Magnehelic that I got from ebay. If you can find a -20 to 0 to 20 or a -50 to 0 to 50 those are good. Keep in mind there are about 27 inches of water column per psi so that last one would display about -2psi to +2psi.

    Several of mine will collect water in them over time unless I put them after a pigtail even though it seems like they shouldn't due to the cushion of air in the supply tube but :shrug:

    Here is an ebay search you can use. Aim for $20-$30 with reasonable shipping...they come up eventually: https://www.ebay.com/sch/i.html?_nkw=dwyer+magnehelic&_fcid=1&_sop=12&_stpos=07009&_pgn=4
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • SteamingatMohawk
    SteamingatMohawk Member Posts: 997
    @ethicalpaul Thanks. How confident are you that they will work, since, at that price, they have to be used? I don't mind saving a few bucks, but reliability and condition mean a lot to me.
  • ethicalpaul
    ethicalpaul Member Posts: 5,695
    I’ve bought about 6 over some months and they all work. They are very well made. If nervous, get one that has a return policy. They can be damaged by over pressure but I haven’t seen an occurrence 
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • theONEendONLY
    theONEendONLY Member Posts: 51
    Update - installed a gorton 2 on my main.

    One of my radiator vents (brand new gorton 6) is getting a bit of water stuck in it, causing it to randomly vent extremely loud. It only happens to this one, all the rest in my house I haven't noticed.

    Maybe a faulty vent?? Pitch is good, slanted down towards the supply.
  • da13ear
    da13ear Member Posts: 30
    @theONEendONLY hey there, happy new year. Following up here - did the G2 stop the rads from venting long and slow?
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846

    One of my radiator vents (brand new gorton 6) is getting a bit of water stuck in it, causing it to randomly vent extremely loud. It only happens to this one, all the rest in my house I haven't noticed.

    Maybe a faulty vent?? Pitch is good, slanted down towards the supply.

    A couple of mine do this. I attribute it to being in a cold location, so condensation forms while the moist air is venting through a cold vent. When it gets on my nerves I take the vent off and shake the water out of it and it'll be fine until the water builds up again.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • theONEendONLY
    theONEendONLY Member Posts: 51
    da13ear said:
    @theONEendONLY hey there, happy new year. Following up here - did the G2 stop the rads from venting long and slow?
    Unfortunately no. I changed a few of my g6's to varivalves so I could play with the vent speed a little bit, slowing them down helped somewhat but it's still not great
  • KC_Jones
    KC_Jones Member Posts: 5,722
    edited January 2022


    da13ear said:

    @theONEendONLY hey there, happy new year. Following up here - did the G2 stop the rads from venting long and slow?


    Unfortunately no. I changed a few of my g6's to varivalves so I could play with the vent speed a little bit, slowing them down helped somewhat but it's still not great
    The varivalves are very aggressive vents. At their slowest they are faster than about half the other vents out there. At 50% they are about the fastest vent you can get and at full setting they are double the speed of a Gorton #1 main vent. They don't offer any "real" control.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    ethicalpaul