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radiators won't heat up

Our radiator on/off valves are stuck in three rooms. In rooms where we want to turn it down--the heat is on constantly; in another room where we actually want it higher it is stuck at a lower out put.

Should we turn all the heat off and try liquid wrench? call the man? purchase new valves?


  • Sue Berg
    Sue Berg Member Posts: 1

    My radiators don't fully heat up. I have a two pipe steam system only one radiator has a steam trap the others do not. I have lived here for over 10 years and no maintenance has been performed on the radiators. I have had several people look at my radiators and they are dumb founded that they do not all have steam traps. Any ideas???
  • Matt Undy
    Matt Undy Member Posts: 256

    Some systems have an orfice on the inlet that restricts the steam flow into the radiator such that the radiator only gets the amount of steam that it can consume(condense into water) so steam never makes it to the outlet of the radiator, so no steam trap is needed. Many of these had a special ell on the outlet that had a water trap built into is (like a tiny version of the j bend under a sink on the inside, but they just look like a sort of squared off ell from the outside). This is probably the type of system you have. (I realized I wrote this assuming this is what you have, if it is some other old time system designed in some other way to work without traps, take the rest of this with a grain of salt, but ultimately you need someone who understand how the original system worked to work on it).

    Is the boiler pressure more than what the system was originally balanced for? Is it using a vaporstat to regulate the pressure to the few ounces of pressure that a steam system is instead of the couple pounds of pressure that the standard controls that come with new boilers produce. If the pressure is in th range of pounds, you will save fuel and make the system heat more quickly and evenly if you install the controls to reduce the pressure.

    Was there insulation that was removed form the piping? Are they currenlty insulated? Can you take pictures of the radiator valve and the radiator valves on one of the radiators without a trap?

    Do you get enough heat out of the radiators as they are now? Might not need to change anything about the distribution system if they part of the radiators that do heat puts enough heat into the room.

    You need to find someone that can identify this system system to fine tune it. If they don't know what it is they are very likely only going to make things worse (unless they read up on these systems). Try looking in the "find a professional"

    BTW, i'm not a contractor, i only know what i've read here and elsewhere.

  • Matt Undy
    Matt Undy Member Posts: 256

    What kind of system is it? one pipe steam, 2 pipe steam, or hot water? If its one pipe steam, you must have the valve fully open or fully closed or the radiator will not drain condensate correctly.

    Are these just ordinary globe valves, or were the one of the valve plate type valves? If its a steam system, you could try shutting it down, backing off the packing nut on top of the stem with wrench, and see if you can get the stem out and clean up whatever is binding the threads. Don't try too hard such that you break something, don't want to take the whole system out of commission. Next step would be to replace the valve unless its something special like an orfice plate or something similar.

    If you don't know how to do this with a compression faucet(radiator valves are the same mechanism as a washer type faucet in most cases), might be best to call someone. If you do call someone, might be about the same cost to have them just replace the valve while they are out there.

    Oh, I forgot to mention, if its a steam system, don't use oil or grease on the steam or in trying to loosen the stem, if it gets inside the system it will contaminate the boiler and cause it to steam poorly.

This discussion has been closed.