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Radiator Service Valves Leakage? Help!

dkirkwooddkirkwood Posts: 14Member
Hi All,
I have a single pipe steam system. Installed new Burnham boiler last wk, with a gallon meter on the auto feed.

It is using 1 gallon of water per week, based on the auto feed meter.

System has 15 radiators. 14 have service valves (1 doesn't). 12 of the service valves appear to be original--probably at least 80 years old--none have any visible sign of moisture leak. All are fully open, and seem to work in terms of being able to turn handle on/off.

Of the 15 radiators, 12 have new speed vents--3 have original vents. The main vents are newish (<3 years)

All piping, supply and return is visible and not buried--a very short length for one radiator exits crawl space, and can't be seen--but it is only about 3 feet from exit to radiator, so it seems unlikely to me it is buried.

So, given 1 gallon/wk loss, and 15 radiators--the average loss per radiator is 1.3 ounces every 24 hours--does this amount of leaking strike you as being caused by bad radiator service valves?

Or, is that amount of loss indicative of a pipe leak or other type of leak? Again, I see no visible leaking on walls, ceiling, or where the supply/return pipes are visible in basement.

I prefer to troubleshoot intelligently, rather than just replacing parts and hoping--but i have zero experience here--so it would help me alot from anyone who has seen this before--particularly if service valves were the leak culprit

Thanks!

Comments

  • Jamie HallJamie Hall Posts: 8,387Member
    A gallon a week is perhaps a little high, but not outrageous. Likely sources are the valve stems (that small an amount of steam is very hard to detect -- try a cold mirror or perhaps tissue) or the "very fast" vents (why very fast? Usually good main venting and slower vents on the radiators works better).
    Jamie



    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
  • nicholas bonham-carternicholas bonham-carter Posts: 7,217Member
    Does the auto feed ever overfill the boiler?
    What is your pressure on the system?
  • dkirkwooddkirkwood Posts: 14Member
    The pressure is 1.5 pounds. As for overfill, the auto feed keeps the level at half-way point of site glass--just above the low water cut off--that said, when plumbers left, they did fill boiler to be 3/4 of the site glass (3/4 full of water)--I marked where the level was, and within a week, it was down to the 1/2 way mark. So, I manually filled to get it back to original mark, and the feeder (which is new) registered exactly 1 gallon as it came up to the mark. I don't intend to fill it again to the 3/4 point on site glass, sI will leave it at half way point--does this info mean anything to you?
  • Jamie HallJamie Hall Posts: 8,387Member
    It does. You're probably fine. Do keep an eye on the autofeeder's meter -- it's a great diagnostic tool. You can look around for steam leaks, but that small a leakeage is almost impossible to find!
    Jamie



    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
  • FredFred Posts: 6,517Member
    What are the "Speed Vents" you refer to on the radiators? Are they something you got from Home Depot or Lowes? if so, Those vents are typically cheap units that aren't very reliable. You'd be better off with Hoffman 1A or Vent-rite #1. Some of the cheaper vents allow a little steam to escape before they fully close and typically fail in a few months. I have a Burnham with 15 radiators on my system, also and a gallon a week is on the high side. I typically only need a quart during the coldest weeks. Check all the radiator vents, all the radiator valves and all the new fittings installed with the new boiler. A joint can leak and the water evaporate and not show up as a leak.
  • dkirkwooddkirkwood Posts: 14Member
    this is what is on most of the radiators--are these no good?

    https://www.amazon.com/Varivalve-925005-00-Adjustable-Angle-Valve/dp/B009ATMA2I
  • the_donutthe_donut Posts: 369Member
    They can cause issues with balancing and sometimes leak steam.
  • Dan_NJDan_NJ Posts: 58Member
    I just had an ah ha moment this week when I discovered the (newish) drain valve on wet return dripping. Only caught it because I've been leaving a small bucket under there after blowing down and this time it almost overflowed. Probably been dripping all season. The buckets are now dry when they go back to their stations so I can see they stay that way till next time.
  • FredFred Posts: 6,517Member
    dkirkwood said:

    this is what is on most of the radiators--are these no good?

    https://www.amazon.com/Varivalve-925005-00-Adjustable-Angle-Valve/dp/B009ATMA2I

    Those Varivalves are so aggressive in venting. We typically tell people to shy away from them. I suspect they may be a part of the water loss issue. I'll bet they are letting a little steam out before they fully close. Over the course of a week, with each heating cycle that adds up.
  • dkirkwooddkirkwood Posts: 14Member
    Thanks for all the advice--the house had Hoffman vents, which were all the same size (I don't remember exactly the size)--but the system was not well balanced--which is why I went w/ Varivalves--the system is balanced well now. Can anyone recommend a better valve (one that won't leak steam), but can be adjusted, to aid in balancing the system?
  • nicholas bonham-carternicholas bonham-carter Posts: 7,217Member
    We like the Hoffman 1a, or the Hoffman 40, which are both slightly more restrictive in back pressure than the main vents, which must have very low back pressure. Balancing the system with radiator vents will burn extra fuel on every heat call to remove the air.
    I would put the 40’s back in place, and enlarge the main vents.
    Having capacious main vents will fill the main pipes first, and then allow the air in all the radiators to escape simultaneously, and steam to come in.—NBC
  • FredFred Posts: 6,517Member
    Either the Hoffman 1A or the Ventrite #1 are adjustable and excellent radiator vents. As has been said, good main venting is a requirement before trying to balance a system. What main vents are you using? Gorton #2 or Barnes and Jones Big Mouth are excellent. If you have large/long mains, the Big Mouth has double the venting capacity of the Gorton #2 at the same price. I use the Big Mouths.
  • the_donutthe_donut Posts: 369Member
    Balance venting of the mains and the risers and steam will arrive to every radiator at close to the same time. Choose the radiator vents by size of the radiator and the system will heat evenly. Balancing by radiator alone is like balancing a knife by the point. Technically achievable but very hard to maintain.
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