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.

new low PSI gauge filling with water

Options
It's been over 11 years since I last posted here. Ever since I've been lurking and finding answers to most of my questions from searching existing posts ... an amazing resource.

Here's an issue I couldn't find in search --

I acquired a new property last month -- the 30 psi boiler gauge isn't working and the pressure seems a bit high (noisy radiators and risers). The gauge will hit about 10lb and even after the boiler is off and cool, it takes many hours to finally hit zero.

So based on the advice I received here many years ago, I replaced the pigtail and added a low psi gauge (5psi). All new piping is red brass. My first boiler has been running with the same exact piping and gauge flawlessly for 11 years so I decided to update the "new" one (Burnham IN-10 installed in 2000) the same way.

The pigtail is connected to the LWCO (McDonnell #67) with a tee to the pressuretrol (PA404A) and gauge (Wal-Rich 5psi).

As the boiler heats up and the gauge dial starts moving a bit, water starts dripping out above the brass connector (not from the connection threads). The water is room temperature, not hot.

I noticed when I fill up the pigtail with water, the water stays there to the top. If I blow into the pigtail or open the LWCO blow down valve, the water will be pushed out and not fill up again.

Wouldn't the water in the pigtail match the water level in the boiler? Based on the sight glass the water level is lower (it's level with the bottom of the pigtail loop). It seems the pigtail is filling up with water and then pushing it into the gauge. I thought it was supposed to leave an air pocket to protect the attached device? Perhaps it's just a defective gauge or maybe an issue with the LWCO? I've tested with an empty and partially filled pigtail. The water still drips from the gauge body.

Any insight will be greatly appreciated. Thanks

Comments

  • JUGHNE
    JUGHNE Member Posts: 11,079
    Options
    The connection for the pigtail must be clear all the way into the boiler. Have you cleaned the LWCO?
    There is probably a better place for the pigtail control to be installed well above the water line.

    The gauge sounds like it is toast.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,635
    Options
    One thing is sure. You have a defective gage. Possibly too much pressure destroyed it.

    Some boiler MFGs go with the "mount it on the #67 LWCO"
    most steam pros frown on that. Why introduce water into something at the water line with any entrained sludge etc? But many are installed that way.

    I would suggest taking everything apart again and cleaning it. Make sure where the 1/4" pigtail goes in the LWCO is clear. Also check the low water cutoff connections and gage glass connections to the boiler as they could be partially plugged as well as the pigtail and pressure control.

    If your old gage would take hours to hit 0 when the boiler was off then the gage was bad or something was plugged.

    Did you adjust the pressure control? Is it working?

    If you put a 5 psi gage on a boiler that was set up for 10 psi or had been running at 10 psi that's what did the new gage in.

    Reset the pressure control and run lower pressure if possible

  • Fred
    Fred Member Posts: 8,542
    Options
    Pigtails mounted on top of the MM#67 is a PITA. In all probability if the pigtail is directly on the LWCO, a third to haft of the Pressuretrol is below the water line. If you can move the Pressuretrol and gauge (may need another new one) to a tapping on the boiler, above the water line, that is what you should do. If you can't move it, put a brass nipple on the MM67 and a coupling so that the pigtail and controls are fully above the water line. You should be able to take the 0-30 PSI gauge off of the boiler and use that tapping for the Pressuretrol and both gauges, with a couple tee's and an elbow or two.
  • JUGHNE
    JUGHNE Member Posts: 11,079
    Options
    If you post pictures of your boiler showing the controls, original gauge and relief valve we may have suggestions for a better location.
  • bklynick
    bklynick Member Posts: 23
    Options
    JUGHNE - I haven't cleaned the LWCO. I'll research that next. I've only had the property since December and finally have time to focus on tuning the boiler.

    EBEBRATT-Ed - I'll check all connections as you suggested. I'd say the 30 psi gauge is definitely bad. After about 4 hours power down, the gauge read 2.5 psi. When the gauge read 5 psi I was able to remove the pigtail without any pressure release.

    The pressuretrol is set to the "standard" 0.5 and 1. The new gauge was supposed to help me determine if it was working, but I removed it after water starting dripping from the body. I shut off the boiler immediately once the gauge started to drip. This happened after a cold start and once the pointer started to move. The pointer still moves when I blow into it. So unless the water damaged the gauge, I don't think it was hit with high pressure.

    Fred - The bottom of the pigtail loop is at the water line, so none of the devices are below. There is one tapping at the same level of the top valve of the sight glass. There is a L4079B1033 pressuretrol (set to 9 psi) on a pigtail connected there. The 30 psi gauge tapping is slightly lower.

    Would it be OK if I used the tapping of the backup pressuretrol, install a tee and put the main pressuretrol and low-pressure gauge on one pigtail and the backup pressuretrol on another pigtail or do they need to be separate (it would seem to be safer that way)?

    I do like the idea of just getting a long nipple and raising the pigtail completely above the water line.

    Photos coming soon.

    Thanks everyone.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,635
    Options
    If you have multiple pressure controls and they are on separate tappings I would keep it that way. It is safer in case 1 connection plugs up you have a back up
  • nicholas bonham-carter
    Options
    If we knew the make of that low pressure gauge, we could avoid purchasing that make in the future.
    Some gauges have been advertised at such cheap prices as to be almost unbelievable!—NBC
  • pecmsg
    pecmsg Member Posts: 4,895
    Options
    If water is getting into the gauge replace the gauge before it fails!
  • pecmsg
    pecmsg Member Posts: 4,895
    Options

  • bklynick
    bklynick Member Posts: 23
    Options
    EBEBRATT-Ed - yes, I agree. Seems to make sense separating the two pressure controls. Maybe I can swap the backup pressuretrol from the high tapping with the primary connected to the LWCO to bring it way above the water line. I am a little weary of changing the configuration from the original install though.

    nicholas bonham-carter - the gauge is a Wal-Rich 1715500. But please note I've been using the same gauge for over 11 years on my other boiler, although it is mounted way above the water line.


    pecmsg - I have a new gauge on order (Kodiak 0-3 psi), but I still have hope for the Wal-Rich after I try some different piping configurations.

    I'm still confused - I thought the purpose of the pigtail was to leave an air pocket between the device and water/steam. Why would water replace the air pocket and get into the gauge? Is the gauge just not able to hold back the pressure? As I stated before, the dripping started immediately after the pointer started moving on a cold start, so I don't think it was high pressure that caused it.

    I'll take some photos once I'm back on site.

    thanks.
  • Fred
    Fred Member Posts: 8,542
    Options
    @bklynick , As everyone says, keep the Pressuretrols on separate pigtails. That is the only safe way to ensure the boiler shuts down should the primary Pressuretrol/pigtail fail or clog. Add the nipple to raise the one on the MM#67. Just remember that pigtail and tapping into the top of the MM#67 will need to be cleaned at least twice each heating season.
    I kind of suspect the gauge you bought was not designed for water/steam applications. A lot of us use this one:
    https://www.pressureworx.com/product/low-pressure-gauge-25-0-3-psi
  • pecmsg
    pecmsg Member Posts: 4,895
    Options
    bklynick said:

    EBEBRATT-Ed - yes, I agree. Seems to make sense separating the two pressure controls. Maybe I can swap the backup pressuretrol from the high tapping with the primary connected to the LWCO to bring it way above the water line. I am a little weary of changing the configuration from the original install though.

    nicholas bonham-carter - the gauge is a Wal-Rich 1715500. But please note I've been using the same gauge for over 11 years on my other boiler, although it is mounted way above the water line.


    pecmsg - I have a new gauge on order (Kodiak 0-3 psi), but I still have hope for the Wal-Rich after I try some different piping configurations.

    I'm still confused - I thought the purpose of the pigtail was to leave an air pocket between the device and water/steam. Why would water replace the air pocket and get into the gauge? Is the gauge just not able to hold back the pressure? As I stated before, the dripping started immediately after the pointer started moving on a cold start, so I don't think it was high pressure that caused it.

    I'll take some photos once I'm back on site.

    thanks.

    If there's water getting into the gauge then the air pocket has already leaked out to allow the water in!
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,635
    Options
    The pigtail is soley to protect the gage or pressure control from steam. I have seen many of both installed without pigtails and they last a long time but you should use pigtails. Some gages are marked "internal sylphon" which means the gage contains an internal seal.

    You don't have to fill the pigtail with water a short exposure to steam won't hurt it a bit and water will collect and condense in the pigtail the first time the boiler runs. Air or water in the pigtail it matters not, pressure is pressure. The air gets absorbed into the water as the pigtail heats and cools and migrates out of the pigtail
  • bklynick
    bklynick Member Posts: 23
    Options
    Here's the photo. You'll notice the pressure gauge is at 2.5 even though boiler has been off for hours. Water level comes up to about the bottom of the loop of the new brass pigtail.

    The tee and low PSI gauge have been removed due to the leaking.

    How long a of a nipple should I install to bring the pigtail up to a reasonable height off the LWCO?

    Thanks.


  • Fred
    Fred Member Posts: 8,542
    Options
    The current height should actually be fine.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,635
    Options
    If it was me I would put it on a 6" nipple with a union between the nipple and the pigtail. Having the pigtail up in the steam space is better. Put a tee on their with a gage. If you see the gage moving you will know your pigtail is not plugged.

    Your other pigtail on the other pressure control looks like black pipe if it is I would put a brass one on.
  • bklynick
    bklynick Member Posts: 23
    Options
    Here's an update:

    As per the advice from EBEBRATT-Ed, I raised up the gauge and pressuretrol.

    At this point it does seem I had a bad gauge from the start. If I blow into it, the pointer will move but I would also hear some air escaping from above the brass connection. That was replaced with a 3 psi Kodiak gauge (build quality not as good as the Wal-Rich but at least it works).

    I also replaced the 30 psi gauge and it now never goes over 2.5 psi.

    Now that that I'm ready to tune, the pressuretrol set to 0.5 and 1, I'm getting a consistent shutdown at 2.5psi and startup at 1.25psi. It was even worse with another pressuretrol I had laying around (almost hit 3psi). Why are these things so inaccurate?

    I'm going to try this next to see if I can get a little lower:

    https://forum.heatinghelp.com/discussion/149944/i-figured-out-how-to-calibrate-a-pressuretrol

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,635
    Options
    Looks good!
    Your running a 1 1/4 lb differential. That's close enough for now. I would adjust the main setting a little lower. Only turn it a 1/2 turn at a time. Then let it cycle a few times before you adjust it further.
    Your cut in is 1.25. try and get that down to .5 psi. If you go too low the burner may not restart. The controls are pretty consistent. the scale markings not so much

    just go a little at a time
    ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,743
    Options
    I used to obsess over the thing too, but after getting things into order, my system doesn't cycle on pressure anymore. And if it did, I wouldn't worry about it.

    You can try what I did and remove the spring from the ptrol to see at what pressure it opens, but other folks here freak out about doing that, which is reasonable, you only do that if you're watching things like a hawk.
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el
  • bklynick
    bklynick Member Posts: 23
    Options
    The top setscrew on the pressuretrol is half a turn before it comes off the spring, the screw head is sticking up from the top.

    The lowest I can get is 0.75 psi cut-in 2.25 psi cut-out, assuming we trust the new 0-3 psi gauge.

    Should I just accept it and move on to the next step (main and radiator venting)?

    Thanks.
  • nicholas bonham-carter
    Options
    Get the mains venting first at a backpressure of less than 2 ounces, then tackle the radiator venting, as some may be over vented.—NBC
    ethicalpaul
  • Fred
    Fred Member Posts: 8,542
    Options
    If you want to try and re-calibrate that Pressuretrol, use the procedure on the link above. It sounds like you are close enough though. If you get good main venting on your mains, you may not reach the Cut-Out pressure on a normal heat cycle.
    ethicalpaul
  • ethicalpaul
    ethicalpaul Member Posts: 5,743
    Options
    That was exactly my experience @Fred
    NJ Steam Homeowner. See my sight glass boiler videos: https://bit.ly/3sZW1el