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TRV not working

question
question Member Posts: 25
I purchased a danfoss Thermostatic Rad Valve w/ Vac Breaker (1 Pipe Steam). My steam pressure is below 1 psi and it seems the room is getting way to hot (79 degrees).The dial is set to the lowest setting. The radiator is pitched properly . Why is the air coming thru the valve which lets the steam into the radiator.

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 8,519
    How about a few pictures of the install. Do you have the actuator screwed on tight? Is the radiator in an enclosure
  • question
    question Member Posts: 25
    TThis is two different radiators 
  • question
    question Member Posts: 25

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 8,519
    edited February 22
    @question

    You showed two different radiators. Are you having problems with both of them? Do the air vents close when the steam gets their? Are you sure the boiler has 1 psi max? Gauges can lie.

    I suppose it's possible you have a defective valve or actuator, looks like they are installed correctly

    Maybe take the actuator off and see if the valve moves
  • question
    question Member Posts: 25
    I have a new vaporstat after replacing one that was set at 1psi and went off at 2.5 psi. The air vents are only supposed to open if its below the set temperature. Since it is 79 degrees it should stay closed the whole time. The problem is the steam is still filling up the radiator and heating the room.
  • Those TRV's will prevent air from leaving the radiator once the boiler shuts off and steam stops coming into the radiator. But if the boiler never shuts off, steam will continue coming into the radiator and heating/over-heating the room. You've got to have an off-cycle for air to fill the radiator again.

    I've put timers on the boiler to allow this to happen once or twice an hour.
    Often wrong, never in doubt.
    question
  • question
    question Member Posts: 25
    The boiler shuts off when it reaches the set point on the vaporstat.  It goes back on when the pressure gauge reads zero pressure. I’m posting two pictures one which shows when the boiler shuts off on pressure the second showing the pressure when it goes back on. 
  • KC_Jones
    KC_Jones Member Posts: 4,622
    It appears you bought the incorrect operator for the steam TRV.  That looks like the operator for a hot water TRV valve.  If I was a betting man I’d say that’s your problem.  Here’s a link to the correct operator for a steam TRV vent.

    https://www.supplyhouse.com/Danfoss-013G8250-Thermostatic-Radiator-Valve-Operator-Valve-Mounted-Dial-Sensor
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    https://www.facebook.com/media/set/?set=a.10202744301871904.1073741828.1330391881&type=1&l=c34ad6ee78
    question
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 8,519
    It says to leave the actuator set on #5 and push it in until you here it click while mounting
    question
  • question
    question Member Posts: 25
    edited February 26
    kc Jones- it is the correct trv.  The item you shared the link to is part of mine.  It is installed on the valve body of the trv. It snaps on and then you tighten a set screw like Eberatt posted.  
  • neilc
    neilc Member Posts: 1,205
    is it possible ?
    is it possible the TRV, being on the floor, is that much cooler down there, and your feeling the warmth at face level?
    is there a cold draft from in under the baseboard?
    I had this bad in my house till I caulked it to the floor.
    or cold air dropping, or drafting, from the window?
    are the vent threads sealed into the trv?
    I don't see tape or goop
    question
  • Clance
    Clance Member Posts: 52
    edited February 24
    hi - I'm a home owner that just installed 2 Danfoss TRVs...
    @KC_Jones may be correct that you could have the wrong one. Look closely at yours - which has the set
    screw to tighten on what looks like metal... and then look at the one from the link that KC posted... the end is plastic not metal and has no set screw to tighten.

    The ones that I bought are like the one KC shows. Below is a pic of mine installed.
    I'm mot sure how yours works but I believe the set screw makes it "Tamper resistant" Maybe try loosening or taking out the set screw and setting the dial...?

    Also, I did have the same issue of one of mine heating the radiator completely when set low, it turned out to be my installation - I didn't push the control knob all the way in/onto the valve insert. I probably would not have realized this if I didn't have another one to look at and compare.

    Heres a link to the PDF of Danfoss TRVs which shows all their TRVs/TRV Parts.
    https://assets.danfoss.com/documents/99867/AF163386458944en-US0101.pdf


  • Clance
    Clance Member Posts: 52
    edited February 24
    I noticed you have Varivalve vents, which can be fast venting.

    I read somewhere that venting TRVs too fast can result in overheating the radiator because the fast venting prevents the TRV from closing properly. Have you tried a very slow vent like a Maid O'mist #4 (that's what I'm using) or at least turning the Varivalve vent all the way down. From what I read, Varivalve Vents don't fully close but maybe if the Varivalve is set at lowest it might be slow enough to allow the TRV to close and allow it to operate.
  • Clance
    Clance Member Posts: 52
    My third thought - @Jamie Hall posted the following on a discussion discussion I started :

    The first thing to do is to get the venting correct so that the rooms stay close to what you would like. TRVs will not compensate for poor balance. If a radiator is heating too fast, the usual fix is to put a smaller vent on it.

    So, you might take off the TRV, loose the fast venting Varivent in favor of something like the Maid O'Mist kit that has the 5 different orifices and start with the #4 and move up if necessary. Then once confidant your system is balanced re-install the the TRV without tightening down the "Tamper Resistant" set screw.

    Here is the Maid O'Mist to which I referred (MAID O'MIST 0220-5L ADJ Angle Steam Valve):
    https://amazon.com/OMIST-0220-5L-Angle-Steam-Valve/dp/B003DV3AGE/ref=cm_cr_arp_d_product_top?ie=UTF8

    Sorry to have posted 3 separate entries... after thought is my strong-suit :)
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 8,519
    @Clance
    good information
  • Clance
    Clance Member Posts: 52
    @EBEBRATT-Ed  - that’s because you all are such insightful teachers.  Couple of weeks ago I didn’t even know what a TRV was :D
    And that’s what makes this site great! 

    Erin Holohan Haskell
  • question
    question Member Posts: 25
    The TRV that I purchase is a bit different than the one in the photo. It is a tamper resistant model ( https://www.supplyhouse.com/Danfoss-013G8240-RA2000-Tamper-Resistant-Valve-Mounted-Dial-Sensor ) The body is the same. https://www.supplyhouse.com/Danfoss-013G0140-Thermostatic-Rad-Valve-w-Vac-Breaker-1-Pipe-Steam-5551000-p

    The TRV opens / closes a valve which lets the air come out through the air vent. If the valve is closed the air can not escape thereby not letting the steam into the radiator. With the varivalve in the closed position it vents slowly. My thought is the valve should not let any air out so no steam should be getting thru. I have decided to put pipe dope on the vent and trv to see if there was any air coming thru before the trv. I was using the white ptfe tape. Now i will use first the tape then the pipe dope. If it was letting air thru before the valve the steam could then get into the radiator.

    @neilc- That was a good thought about there being a cold draft but there is none.
  • Jamie Hall
    Jamie Hall Member Posts: 15,350
    It is quite true that when a TRV closes no more air should come out of the radiator. However, that does not mean that more steam can't get in -- and keep heating the radiator. As the steam that is in there condenses, more steam will come in and the radiator will keep right on heating at whatever it was doing when the cycle started.

    Now when the cycle stops, if the TRV should let air back in (or, if not, other vents on the system will) -- but if, when the next cycle begins, the TRV is already closed, no air will come out and the radiator won't heat.

    This, in a thumbnail, is why it is essential that the system be balanced properly first. A TRV can't compensate for a poorly balanced radiator.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Clance
    Clance Member Posts: 52
    Did you happen to Read the article linked below by Dan Holohan it's insightful- it also mentions that higher system pressure is an issue. And as I mentioned earlier I read somewhere that too fast of a radiator vent will not give the TRV enough time to close and could keep it from closing.
    Here's the Holohan article:
    https://heatinghelp.com/systems-help-center/rethinking-trvs-for-steam-systems/
    question
  • question
    question Member Posts: 25
    @ clance- I had some bad experiences with maid o mist air vents in the past . Maybe they were a bad batch but I had 12 of them crack on the body which then caused leaks throughout the building and damaging the wooden floors. They all broke at different times . I was recommended to try the hofmann 41 which is a slow venting Air valve.
  • question
    question Member Posts: 25
    It seems to have gotten somewhat better with putting the pipe dope on the threads along with the tape. My guess is there maybe a small leak in the packing nut on the shutoff valve and or the union. 
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