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How come the gauge reads 6 PSI ?

Shalom Member Posts: 165
edited December 2014 in Strictly Steam
Basically what it says. I've got one of these combination vacuum/pressure gauges. When the boiler is cold, it sits over to the left in the vacuum region. When it fires up, the needle starts moving over to the right. It was reading 3 PSI when the end of the main was still stone cold. (At this point I even unscrewed the vent and put my hand over the opening and didn't feel any air coming out.) Once the mains were hot all the way to the vents, it was reading 6 PSI. The pressuretrol is set as far down as it will go, which is somewhere between 0.5 and 1, and the diff is also at 1. (It's a microswitch unit, not a mercury unit, if that means anything.)

I have another gauge in the system right next to the vent (0-50psi, 60-260℉) which shows steam, as the temp needle is right around 210℉, but the pressure needle sits on the pin at 0psi. (Admittedly this one may be broken. I just put it in because it looks really cool up there.)

I did have the PSE&G guy out here to look at it last heating season (I'm paying for "Worry Free" service on it). He said if it shows 3PSI when the main is barely warm, which it did, then there's probably something wrong with the gauge, but that if he tried to order another one they'd laugh at him. G_d knows if you can even get such a gauge today, it's original equipment on this boiler from 1966 or so.

So I'm wondering. Is it possible for there to be 6psi in the boiler, but up in the pipes, barely enough to move steam? Only thing I could think of that could cause that would be restriction or clog in the risers, but you'd probably hear it if that was the case.

(Edit: there's one on ebay now for $23 shipped, but as the needle on that one is sitting on 1PSI when it's not even installed on anything, who knows if it's any good either. linky)


  • KC_Jones
    KC_Jones Member Posts: 5,741
    In a word No. Have you checked your pigtail on the pressuretrol to verify it isn't blocked? It doesn't sound like it is, but it's always good to make sure. Even if the gauge was perfect it probably wouldn't move anyway. the 0-30 psi gauges are useless and the 0-50 you have even more so. Get a good low pressure gauge 0-3 psi or so and put a tee under the pressuretrol and connect the new gauge there. You should then be able to see what is actually going on. I would guess that gauge is toast, but like I said even if it wasn't it's useless on these low pressure systems.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • nicholas bonham-carter
    If that Gorton #1 in the picture is the only vent you have on that main, then you should add at least one more Gorton #2.
    Then only a new 0-3 psi gauge will show you what the pressure is. I would buy it not from eBay, but from a reputable supplier.
    Sell the non-working gauges on eBay with all the others on there!--NBC
  • Fred
    Fred Member Posts: 8,542
    edited December 2014
    Is your Pressuretrol original to the boiler also? Make sure it is working. It sounds to me like it is either not working or the small orifice inside the threaded base is clogged or the pigtail is clogged or it is WAY out of calibration (I have attached claibration instructions below). I have had them out of calibration by 4 or 5lbs. Also make sure the linkage inside the Pressuretrol hasn't come loose. Sometimes when you crank the differential down to .5PSI or try to go a little lower, the link that dial is connected to will drop off the end of the screw.
    #2 Those 0-30PSI and 0-50PSI gauges are useless when measuring ounces but when the pressure gets around 3 or 4PSI or more, they do start to register and we don't believe them.
    It is not likely the risers on the boiler are clogged. Actually most unlikely. Either you have huge vents on the radiators, before the end of the main that is allowing the steam to take those paths (as the paths of least resistance or you are really under vented on the mains. That single Gorton #1 is about as close to no venting as you can get on a Main which may make some of the radiators the path of least resistance. Put some additional vents on the Mains. The suggested amount of venting is one Gorton #2 for every 20 feet of Main. It takes 4 Gorton #1's to equal the venting capacity of a Gorton #2.
    Also make sure you don't have a lot of oils (dirty boiler water) That can make the boiler run a lot longer than it ordinarily would. If you see a lot of bounce in the sight galss water, skim it and do so very slowly, using a skim port above the boiler's normal water line.
    Inside the Pressuretrol, right below the micro switch, there is a pivot arm. At the end of that arm you will see a screw pin that is activated by the diaphragm at the bottom of the Pressuretrol. If you look very carefully at that screw pin, you will see it actually has a tiny (I mean tiny) hex head on it. It takes a .050 hex wrench and you can turn it clockwise (Towards the bottom of the Pressuretrol to decrease the Cut-out pressure or counter clockwise to increase the cut-out pressure (which none of us want to do but who knows, your Pressuretrol may be really screwed up!). Turn the power to the unit off first. You may find the first attempt to turn that screw a little bit stubborn (relatively speaking) because it has some Locktite on it but it does turn. Don't turn too much, a fraction of a turn goes a long way towards getting it adjusted where you want it (maybe 1/32 inch turn to start with). You may need to play with it to get it exactly where you want cut out to be.
  • icesailor
    icesailor Member Posts: 7,265
    The "Tridicator" hot water boiler gauge doesn't even belong on that boiler.

    My old dead boss always said to never believe a gauge unless you had two brand new ones and tried them both and they both read the same. Then, if they both read closely to the same, you had a 50% chance that one was correct.

    Unscrew the gauge from the boiler. If the gauge doesn't drop to zero, then what if shows now, (6#) may be close to zero in what it is actually reading. What it actually is reading is anyone's guess.

    Any possibility that that gauge is older than yourself?
  • Shalom
    Shalom Member Posts: 165
    I'm sure that square gauge is older than myself. Per the date on the cover, the boiler it's on was installed five years before I was born, and it's probably original equipment.

    (The PSE&G guy did try to unscrew it, but it wouldn't move. He was afraid of breaking it off at the neck, though, so he desisted. Better a broken gauge than a hole, right?)

    As far as the vents ... that Gorton #1 has got to vent faster than a pipe plug, which is what was there before I installed it (see my earlier thread). Over the next couple days, when I have time, I'm going to time how long it takes for the steam to get to the vent vs. unscrewing it and just leaving the hole open. If it's pretty close to the same, I'm going to leave it as is. There are only 3 radiators on that main, and they've all got #5 vents on them, so I'm pretty sure even with the #1, the main will vent faster.

    Once I have the timings, I'll post back here with what I've found. The other main has five rads and the same #1 vent; I'll time that one as well and see what happens.
  • icesailor
    icesailor Member Posts: 7,265
    The PSEG guy has no Cajones. We Pro's get right in to it. If it breaks off, we get the remains out and put something else back in.

    How do you get any experience unless you break a few things. Most things are broken by using the wrong tool or the wrong sequences or operation. It's only 1/2" brass. Beat on it with the properly sized open end wrench, 3/4", 13/16" or 7/8" with a 4# hammer, it will come.
  • Pumpguy
    Pumpguy Member Posts: 663
    I see this all the time on 2 pipe vacuum condensate return pump sets. You might try zeroing the needle. With everything cold and the water level below this gauge, the reading should be at zero. If not, remove the glass cover and move the needle by hand so when free, it springs back to zero.
    Dennis Pataki. Former Service Manager and Heating Pump Product Manager for Nash Engineering Company. Phone: 1-888 853 9963
    Website: www.nashjenningspumps.com

    The first step in solving any problem is TO IDENTIFY THE PROBLEM.
  • Captain Who
    Captain Who Member Posts: 452
    I think that is simply due to the internal syphon being gunked up or plugged up. There is now a sealed chamber of air there and any percolation of heat through to that chamber of air makes it warm up and the pressure to rise or fall (as it cools off). It is reacting more to temperature now, than boiler pressure.
  • icesailor
    icesailor Member Posts: 7,265
    Or the spring is bent from overpressure when it was clogged up.

    I see many pressure gauges on drained heating and water systems get twisted when they freeze. Unless you have a accurate gauge to compare it with, just because they both read zero, doesn't mean that both will read 10# at the same time.
  • Don_197
    Don_197 Member Posts: 184
    GENTLEMEN.....ARE WE positive THAT THE COMPOUND GUAGE IS READING psi??? COULD THAT NOT BE iwc?? If he is getting anywhere near 6 on that guage and it is psi, he has pressuretrol problems as well.