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Replacing sight-glass and couplings - what am I in for, what do I look out for?

My sight glass is leaking, and I have an appt. Tuesday for a service person to come help troubleshoot a fix. In the meantime, I need to also learn more myself. (This is also the same service person who may be evaluating replacing the auto-feeder from my other thread, but this seems to be a separate issue occurring in parallel.)

As a separate issue to repairing the glass and leak, whoever installed the fittings for the sight glass reversed the top and bottom position of these L-shaped fittings with the valve perpendicular to the fitting elbow, and instead of swapping top and bottom so the valve exited on the observer's left, they removed the valve handles because they would have impacted against the other Y-fitting that goes to the auto feeder.

Why they didn't realize this is something I can't say, maybe there's something I don't know, but swapping top and bottom would have given plenty of room for the handles. There is plenty of room where a handle could be parallel to the elbow (as I've seen in other fittings) or exit on the observer's left.

However, the bottom stem that the handle normally screws into has been opened/closed so many times with pliers, I am very afraid that it will not be able to be opened/closed much more, and while I have it leaking quite a bit, I have opted to close it so my boiler feeder isn't kicking on each day to fill things again. You can see in the pictures that the top stem is relatively unmarred, but the bottom one is badly mangled and almost half of it is worn away from the plier's teeth.

So I have 2 things to fix: the sight glass leak, and then the fittings themselves. I used some calipers to measure the outer diameter of the fitting's threads the best I could and they measure .85 inches, or 17/20ths, which seems dang close to 3/4 given there is gunk on them and the threads may be slightly wider when measured than the fitting's labeled size.

I am looking at this replacement kit on Amazon that says it is 5/8", so I am not sure if that would go right into the Y-fitting that you can see in the picture.

If it would fit, what is the procedure for changing the fittings and replacing the whole sight glass assembly? I presume I'd depower the boiler and open the valves and drain the water down below the level of the lower valve, and then just unscrew the compression nuts and remove the glass, then unscrew each fitting from the Y's and put the new ones in with some high-heat teflon tape, then cut the glass to size and apply the compression nuts, and we're good as new?

And a somewhat obvious question I still need to ask: could I swap the top/bottom fittings and keep them if I can't find replacements right away? This would put the valve with the mangled stem on the top, and the one that is still intact on the bottom where I could reattach a handle properly. I know this is not ideal, but between finding the right parts, getting the right knowledge, and the right service help, I still have a few weeks of heating before I could consider going without hot water.

Okay, thanks forum folk, guide me as you have done so well in the past!
















Mad Dog_2

Comments

  • 109A_5
    109A_5 Member Posts: 1,341
    Hello @seandempsey,
    I am all for DIY for many reasons. However you may want to consider in this case, since we are still in the heating season and your Boiler also supplies your home's DHW the services of a pro in this situation. Here is why. If things go badly with the repair, the pro should have more experience and resources to quickly recover from the issue. Also the experience and resources of a pro may avoid issues in the first place.

    The repair parts (of various quality) are readily available from multiple sources if you choose to do the job yourself.

    5/8" or 16mm is the outer diameter of the glass of the water gauge, it's a common size, but verify.
    ".85 inches" is very close to the outer diameter of 1/2" pipe.

    As I stated in the other thread since, I repaired my own and hopefully I used parts to provide many many years of trouble free service. A low cost upgrade.

    Another thing, do you have the tool to cut the glass tubing to fit your application ? If you DIY you may have to buy it pre cut like I did. Not a big deal but if you buy a typical assembly ( many at www.supplyhouse.com ) the glass may need cutting once you receive it. And if you break it wrong...

    BTW when mine started leaking I drained the water down below the leak, cleaned it up and brushed on some tacky automotive gasket sealer (that I already had) and let it set to dry a bit. It did last for a while, then I repaired it correctly (off season). And I had more of a mess to clean up to get the gasket sealer off the compression nut, since I did not replace the valve assembly.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    Mad Dog_2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 6,701
    Wait for the guy...you're playing with your Low water  cutoff too  Mad Dog
    109A_5
  • dko
    dko Member Posts: 557
    edited March 2023
    Your replacement valves will have the handle facing outwards (towards the camera).
    You described all the proper steps, but most likely the hardest part will be removing the valves from the Y-fittings. You will need some heat and proper wrenches to both loosen and hold back. Those Y-fittings are not cheap, will run you $200 a pop.

    Cutting glass for the first time is also nerve-wrecking. It takes a deep breath and a leap of faith when you do it for the first time. You'll want extra glass if you don't have a local supplier.

    I do not see any reasonably priced boiler sight glass kits on Amazon. Search part number 1723002 on supplyhouse.com for a more reasonably priced kit.

    Or you can save the hassle and pay the service man for something you'll probably not end up doing again for the life of the boiler.

    Mad Dog_2
  • 109A_5
    109A_5 Member Posts: 1,341
    BTW with the glass tubing length, if you buy it pre cut you have to measure it first and get it correct. Too short and it won't seal correctly, too long it won't fit the application.
    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
    Mad Dog_2hot_rod
  • 109A_5
    109A_5 Member Posts: 1,341
    Hello @seandempsey,
    Here is an example picture (stolen from another posting) of the use of a Tee to offset the water sight glass assembly. In this picture it is offset to the Right you may need to offset yours to the Left if the new valves need the clearance.


    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • seandempsey
    seandempsey Member Posts: 28
    109A_5 said:

    Hello @seandempsey,
    Here is an example picture (stolen from another posting) of the use of a Tee to offset the water sight glass assembly. In this picture it is offset to the Right you may need to offset yours to the Left if the new valves need the clearance.


    I like that, yeah. Question: those parts like the T and the plugs in the end, if I were to go to local stores that carry fittings, are they brass water fittings that are generic and not specific to steam systems or boilers? I feel like I could go browse Home Depot or something and gather some parts while I wait for the technician, in case he had a solution and we need things, I could try and get them ahead of time.

    I ordered a sight glass kit and "thick walled" sight glass, and a cutter, and a set of the valves, so a T and the end plugs could be sourced locally. There were a bunch of YouTube videos on this process, I'll watch a few and see what the tech says Tuesday, if he has parts or thinks there's anything we can do to get by until more advanced replacements can be made.

    I think this is also prompting me to do some research on what will happen if I get a separate new water heater and take the DHW away from the boiler, and then learn how to maintain and monitor a cold-start boiler and what that entails.


  • 109A_5
    109A_5 Member Posts: 1,341

    Question: those parts like the T and the plugs in the end, if I were to go to local stores that carry fittings, are they brass water fittings that are generic and not specific to steam systems or boilers? I feel like I could go browse Home Depot or something and gather some parts while I wait for the technician, in case he had a solution and we need things, I could try and get them ahead of time.

    I would think Home Depot (you may be able to check your local store's stock on-line) or the like would have brass fittings if not supplyhouse.com does. Just save the receipts and if you don't need them you can return them. And as long as your service pro does not mind using parts you supplied.

    There are different types of brass (Red, Yellow, lead free), Home Depot probably just has imported stuff. For this application, not sure if it matters much.

    National - U.S. Gas Boiler 45+ Years Old
    Steam 300 SQ. FT. - EDR 347
    One Pipe System
  • Long Beach Ed
    Long Beach Ed Member Posts: 1,188

    Buy an extra glass or two. Cutting them can be a learning experience.

    mattmia2pecmsg
  • mattmia2
    mattmia2 Member Posts: 9,412

    Don't you just score the tube with a file and snap it? Looks like they come in a box of 6 from supplyhouse.com.

    I don't see any reason why the brass fittings won't unscrew from eachother with proper wrenches. It looks like a straight gauge glass set would fit in your application. the one with the valves to the right probably was there before the lwco was added.

  • EdwinD
    EdwinD Member Posts: 159

    For materials, recommend supplyhouse.com. Rather than buying a kit, it's cheaper buying parts separately. I purchased the gauge glass, gauge glass friction rings, and gauge glass rubber washers separately. Best advice I can give is don't overtighten nuts holding glass in place - finger tighten then 1/4 turn with wrench is enough. Of course, plenty of installs on youtube. If your glass needs cutting, Ace Hardware in my area did it for free. see links below.

    https://www.supplyhouse.com/Wal-rich-2712006-Gauge-Glass-Friction-Ring

    https://www.supplyhouse.com/Wal-rich-2715004-Gauge-Glass-Washer

    https://www.supplyhouse.com/Westwood-Products-H1-12-12-5-8-O-D-Standard-Gauge-Glass-6-Pkg

    Weil-McLain EG55 2 pipe Vapor System
    OP Pressure .10 -.25 oz
    8-Way Boiler Water Treatment
    Barnes & Jones Big Mouth Vents
  • seandempsey
    seandempsey Member Posts: 28

    Sight glass assembly, valves and glass, was able to be replaced with no fuss. For any future Google-searchers who arrive here looking for the same topic, the valves unscrewed without a problem or any heat needed, and the new ones went right in and we were able to verify eveyrthing is sealed and working.

    Still monitoring with the WiFi camera for the instanaces of unexplained overfill, but that was on hold while the glass was leaking and had no handles.

    Now back to what the current observation task was, the operation of the auto-feeder for replacement here over the course of the summer season.

    ethicalpaul109A_5
  • ethicalpaul
    ethicalpaul Member Posts: 5,585

    Nice! Now you just need @Gordo 's sight glass drain valve installed on there

    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
    Gordo109A_5