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.

3-4 PSI with no obvious reason

Hi everyone. I'm a first time steam boiler owner. When we moved in to our house a year ago, we had to replace the old Oil Steam boiler. So we had a gas line run and installed a Peerless Series 63 (One Pipe System). What I've learned about my heating system since then has been both fun, and frustrating, as steam seems to be temperamental. Everything from tefloning and tightening packing nuts to sizing air vents based on location.

I think I still have a problem, but thats why I'm here. As the system stands now, I don't lose water, there is no hissing, knocking, banging, water shooting or dripping. Every radiator (8 total) has a new, appropriately sized (Non-Adjustable) air vent that gives a slight whistle when steam is delivered that peters out within a minute. No cold spots, no uneven heating or otherwise....BUT my system seems to be overpressurizing. After approx 10 min of firing, the PSI on the Pressuretrol slowly rises to about 3.5-4 and then one of three things happen: the thermostat reaches temp, the pressuretrol cuts the burner, or the LWCO does that 15min kill the boiler for 90 sec thing.

All else the same, I CANT figure out why it's building pressure. Our home is 2000sqft in the NorthEast US, and numbers tell me that the BTU of our system should be approx 100,000, but the (GROSS OUTPUT) of our boiler says 123,000BTU. So I dont know if we're just oversized or if I'm missing something. The Water level in the sight glass is murky, but stable.

Any help, criticism or otherwise is greatly appreciated.

Comments

  • pecmsg
    pecmsg Member Posts: 5,228
    Post some pictures of the boiler and its piping.
  • KC_Jones
    KC_Jones Member Posts: 5,789
    What gauge are you using to see that pressure? The 0-30 PSI that came with the boiler, or do you have a good low pressure gauge installed? 0-30 are notoriously inaccurate at the bottom of the scale so I wouldn't trust it.

    Pressure is a function of boiler size, to system, to venting. To build pressure you have a boiler producing more than the system can use.

    Did you add up the EDR of all the radiators in the house and compare that number to the boiler rating (sq ft)? That will most likely tell the tale, if you are actually getting to those pressures.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    ethicalpaul
  • pecmsg
    pecmsg Member Posts: 5,228

    Hi everyone. I'm a first time steam boiler owner. When we moved in to our house a year ago, we had to replace the old Oil Steam boiler. So we had a gas line run and installed a Peerless Series 63 (One Pipe System). What I've learned about my heating system since then has been both fun, and frustrating, as steam seems to be temperamental. Everything from tefloning and tightening packing nuts to sizing air vents based on location.

    I think I still have a problem, but thats why I'm here. As the system stands now, I don't lose water, there is no hissing, knocking, banging, water shooting or dripping. Every radiator (8 total) has a new, appropriately sized (Non-Adjustable) air vent that gives a slight whistle when steam is delivered that peters out within a minute. No cold spots, no uneven heating or otherwise....BUT my system seems to be overpressurizing. After approx 10 min of firing, the PSI on the Pressuretrol slowly rises to about 3.5-4 and then one of three things happen: the thermostat reaches temp, the pressuretrol cuts the burner, or the LWCO does that 15min kill the boiler for 90 sec thing.

    All else the same, I CANT figure out why it's building pressure. Our home is 2000sqft in the NorthEast US, and numbers tell me that the BTU of our system should be approx 100,000, but the (GROSS OUTPUT) of our boiler says 123,000BTU. So I dont know if we're just oversized or if I'm missing something. The Water level in the sight glass is murky, but stable.

    Any help, criticism or otherwise is greatly appreciated.

    You don't size steam by BTU's.......................What's the Total EDR in the house
    ethicalpaul
  • thepiperofseville
    thepiperofseville Member Posts: 12
    Let me get the EDR and I'll get back to you guys.

    And yes, I'm looking at the 0-30psi Standard Gauge. I've heard they're unreliable and will be adding a 0-3PSI LPG as soon as I can. Would you be able to recommend a good one?
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    The boiler would be oversized if its output EDR is greater than the total EDR of the attached radiation. To figure this out you need to find the EDR of each radiator and add them up. To find the EDR of each radiator, first you need to identify it, then you need to look it up. To help you with this process, there is a book available here: https://heatinghelp.com/store/detail/e-d-r-ratings-for-every-darn-radiator-and-convector-youll-probably-ever-see

    I'm not trying to sell you a book, but it sounds like you're the kind of person who enjoys learning new things and figuring things out for yourself. If you'd like some help or you want to get up to speed faster, most of the people here own a copy of that book and are happy to look things up for you. Also, occasionally you might come across something that isn't in the book, but the pros here will recognize it if you can post a picture of every radiator you want to identify.

    In addition to pictures of the bare radiators, sometimes it's helpful to show any covers or cabinets that might be in use. Good radiator cabinet design is very technical, but a lot of people wing it and end up reducing their radiators' EDR, and if you reduce the EDR of every radiator, you may end up with an oversized boiler.

    If your boiler is, indeed, oversized, depending on which model you have, you might be able to downfire it. For every series 63 boiler, there is a corresponding model ending in "L" which has the same number of sections but one less burner, so, unless your model ends in "L," you can swap out the burner manifold, rear support and flue collector from the corresponding "L" model (You'd need a professional to do this job because the gas valve needs to be adjusted for the new setup.), and have yourself a balanced system.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • KC_Jones
    KC_Jones Member Posts: 5,789
    NHOwner said:

    After approx 10 min of firing, the PSI on the Pressuretrol slowly rises to about 3.5-4 and then one of three things happen: the thermostat reaches temp, the pressuretrol cuts the burner, or the LWCO does that 15min kill the boiler for 90 sec thing.

    Ok, how do you know which is which? the thermostat reaches the temp which shuts the burner? Or the pressuretrol reaches max pressure which shuts the burner? The LWCO only kicks in when your boiler is low in water level. So i don't understand how LWCO plays into all of this.

    He has a Cycleguard LWCO, they shut the boiler down at fixed intervals to allow the water to settle and verify the level. So it can indeed "randomly" shut the boiler down.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    mattmia2
  • thepiperofseville
    thepiperofseville Member Posts: 12
    edited January 2022
    Hey again. My Calculated EDR is 342 (38" H, 6 Tube ea. , # of Sections: 4,5,6,6,8,8,8,12)
    Boiler Sq.Ft. is 383...How screwed am I?

    Correct, I have a Cycleguard LWCO.

    NHOwner - Honestly, it depends. It's a crap answer but as far as I know, the pressuretrol is set to 1 with a 3 differantial, the LXCO does this thing where a green light pops on (Intermittent Testing) and then the boiler shuts down, or the therm hits temp (depending on hoe cold it is)

  • Dan_NJ
    Dan_NJ Member Posts: 254
    123,000 - sounds like a 63-04L - if so it's already the lower fired version of that one.
  • Dan_NJ
    Dan_NJ Member Posts: 254
    If the boiler really is oversized the cycle guard will mitigate that condition to some extent.  I'm glad I kept mine.
    Hap_Hazzardethicalpaul
  • neilc
    neilc Member Posts: 2,785
    unless you have special circumstances,
    the Ptrol(s*) should be set to cut out ~1.5,
    and cut in ~0.5,
    so approx 1 on the differentials,
    * (, , , both of you)
    known to beat dead horses
  • neilc
    neilc Member Posts: 2,785
    I would call that 1.5 diff,

    and know too, the scales on there can be off a bit also,

    set the diff down to 1,
    and lower the main down to the mark under the marked 2,

    turn up the thermostat, and watch a cycle or 2,
    see if you can dial the main down to where it shuts off closer to 1.5,
    and that the boiler restarts at the 0.5, consistantly,
    if by chance it doesn't restart, either raise the main a hair, or lower the diff slightly,
    known to beat dead horses
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846

    Hey again. My Calculated EDR is 342 (38" H, 6 Tube ea. , # of Sections: 4,5,6,6,8,8,8,12)
    Boiler Sq.Ft. is 383...How screwed am I?

    Not terrible, but if you've insulated your pipes, your pickup factor may be less than the rated EDR output assumes, and if there are covers on your radiators that impede convection, your radiant load might be lower than the sum of the ratings.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • Jamie Hall
    Jamie Hall Member Posts: 24,479
    neilc said:

    I would call that 1.5 diff,

    and know too, the scales on there can be off a bit also,

    set the diff down to 1,
    and lower the main down to the mark under the marked 2,

    turn up the thermostat, and watch a cycle or 2,
    see if you can dial the main down to where it shuts off closer to 1.5,
    and that the boiler restarts at the 0.5, consistantly,
    if by chance it doesn't restart, either raise the main a hair, or lower the diff slightly,

    That's a subtractive pressuretrol. Careful! What it is set for now is a cutout of 2 and a 1.5 differential, which gives a cutin of 0.5 You could set the cutout lower, but you'd also need to set the differential lower. but without a low pressure gauge I wouldn't even try to adjust it from where it is. Leave it alone.

    I suspect that the boiler is somewhat oversized, but not seriously so.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • neilc
    neilc Member Posts: 2,785


    That's a subtractive pressuretrol. Careful! What it is set for now is a cutout of 2 and a 1.5 differential, which gives a cutin of 0.5 You could set the cutout lower, but you'd also need to set the differential lower. but without a low pressure gauge I wouldn't even try to adjust it from where it is. Leave it alone.

    I suspect that the boiler is somewhat oversized, but not seriously so.

    yup,
    and I wrote to set the diff to 1,

    all good, it's just me workin from the bottom up,
    known to beat dead horses
  • bmma
    bmma Member Posts: 36
    Definitely get the low pressure gauge to see what's really going on. It sounds like your pressuretrol is set to cutout at 2psi so if you really are getting up to 4psi you're pressuretrol may not be working properly or wired properly.
  • thepiperofseville
    thepiperofseville Member Posts: 12
    Hey everyone! Thank you so much for all your input. I took some pictures of my set-up and of the Pressuretrol.

    I noticed the adjustment tab on the pressuretrol is kind of cocked, and it wont adjust, if I move it it just goes back down. The differential wheel is set to 1. Shouldn't that Silver tab be both straight AND able to be adjusted?

    Pics - https://imgur.com/a/4EHcviz

    Maybe it IS the pressuretrol?
  • neilc
    neilc Member Posts: 2,785
    yeah, don't force it any lower or the linkages will disconnect,
    that looks set good enough,
    even as a new boiler,
    do you know your pigtail is clean and free breathing, all the way back into the boiler ?

    and also, in the pictures notes,
    you say sightglass is full,
    to the marked ring on the glass?
    or up past the top?
    is the water line hiding behind the rubber rings?
    it should be, that's your normal water level, as noted on the boiler
    known to beat dead horses
  • thepiperofseville
    thepiperofseville Member Posts: 12
    neilc -

    Yes, the water level is sitting right at that Black rubber ring, per the installers recommendation.

    Concerning the cut in - if its set @ 1, with the diff set at one, isnt it supposed to cut out at 2? I cant even move that lever...if i push it up it just forces it self back down.

    The psi have gotten to 4 without the boiler shutting off.
  • neilc
    neilc Member Posts: 2,785
    does the gage go to zero when the boiler is off between calls for heat?

    water level is good then,

    Ptrol settings are good also, your understanding is correct,
    but,
    can you raise the setting on the front scale up to 2, or 3, just temporaily to show that the linkage is still connected inside?
    then just set it back down when the indicator does move , , ,

    then,
    is the pigtail clean and free breathing all the way back into the boiler?
    maybe pressure isn't getting to the Ptrol,
    you'll need to remove the Ptrol from piggy, and blow back into piggy, once the water loop clears, it should be free breathing to the boiler,
    prime a 1/4 cup of water into piggy before reinstalling Ptrol
    known to beat dead horses
  • Jamie Hall
    Jamie Hall Member Posts: 24,479
    When you are trying to reset the pressuretrol, are you pressing on the indicator tab, or are you turning the adjusting screw? If you are pressing on the tab, it won't work...

    If the pressure has gotten up to 4 psi without the boiler shutting off, either the pressuretrol isn't seeing the boiler pressure (clogged pigtail, clog in the base of the pressurtrol, clog in the tapping in the boiler) or it is defective -- which is unlikely -- or it is wired incorrectly. The wires are on the correct terminals in the pressuretrol, but is it really in series with the other safeties as it should be?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • thepiperofseville
    thepiperofseville Member Posts: 12
    Oh my God I get it now. The Pressuretrol tells the boiler, based on the PSI in the system, that we enough steam in the system to successfully heat the radiators. As the steam in the radiators cool and condenses, it trickles BACK to the boiler thus reducing the pressure in the system. Once it goes down to .5, if the thermostat is still calling for heat, it kicks on again, and does the same thing in cycle. Making anymore than 1.5 psi of steam IS a waste because the radiators cant DO anything with it, so it just increases the pressure, fuel used, and cost.

    The more I learn, the stupider I realize I am.

    OK, so the problem, given all else is OK, has to be in the pressuretrol, most likely in the Pig tail as the pressuretrol is a year old, as is the boiler. The guys who did the system have skimmed it twice since installation but given the haziness of the glass, could probably use another go.

    So now, I have to learn how to clean the pigtail (without destroying the boiler, or myself), and clean the sight galss (again, maintaining everything involved)

    Thoughts?
  • jhewings
    jhewings Member Posts: 139
    edited January 2022
    The site glass is easy. Close the 2 valves top and bottom. Lift up the 2 protective rods next to the site glass. Back off the nuts holding the glass in place. They each have a rubber gasket next to the glass. The nuts should not be very tight but you might need a crescent wrench. After the nuts are separated from the valves, lift the glass up and carefully pull the glass out from the bottom. I use a little bottle brush thingy while running water through the glass at the sink. Put it back in reverse but don't tighten the nuts much beyond finger tight. I go finger tight then a little further with the crescent wrench. Open the 2 valves.
  • jhewings
    jhewings Member Posts: 139
    edited January 2022
    The pigtail. Shut the power off. Remove the wires from the pressuretrol. Spin the pressuretrol off using a wrench at the bottom - don't turn the box with your hands. Generally the advice is: see if you can blow through the pigtail into the boiler. If you can't, try poking a plastic zip tie through to clear the muck. After you can blow through to the boiler, add 1/4 cup of water to the pigtail to create the water seal. Spin the pressuretrol back on and reconnect the wires.
  • Jamie Hall
    Jamie Hall Member Posts: 24,479
    I can't see enough of how that pressuretrol is mounted, so I can't give you all the directions, but... you want to make sure that the passages all the way back into the boiler are clear.

    Clearing the pigtail (the curly piece) isn't going to be hard. You will need to take the wiring off the switch inside the pressuretrol (mark on the wire which one goes where -- makes life easier)! and then unscrew the pressuretrol from the pigtail. Use only the hex on the bottom to turn it -- do not use the case, however attractive that may be!. Then unscrew the pigtail from the fitting below it and just make sure that water can run freely through it. As I say, I'm not sure from the picture how the connection from there to the boiler is made, but it needs to be known to be clear as well -- and the easiest way to check may be with a funnel and pouring water down through it (hey -- whatever works). Then screw the pigtail back on (use new tape) and the pressuretrol back on, hook up the wires and you're done.

    Cleaning the sight glass is not much harder -- but sight glasses are super fragile, so it's not a bad idea to have a new one on hand.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • thepiperofseville
    thepiperofseville Member Posts: 12
    OK. For the sight glass AND the Pressuretrol, obviously the power needs turned off. Do I need to drain, lower, or otherwise change the amount of water in the boiler for either operation?

    I cant have the boiler off TOO long in my climate at the moment, but should how long should I let it cool before attempting all this?

    I'm so thankful to all of you for your guidance. I'm going to pick up a spare sight glass at HD tomorrow before attempting either thing.

    Additionally, there does seem to be alot of dirty water in my boiler (Maybe because its newer, or it was put on a REALLY old system) Am I able to safely skim and clean the boiler myself or is that a job best left to the professionals?
  • jhewings
    jhewings Member Posts: 139
    You don't have to lower the water level to do either one. If you can hold the parts with your hands not too hot then go for it. If you have a skim port with a valve I think you could do it. Try a search here for skimming.
  • bburd
    bburd Member Posts: 997
    @op Just to be clear: as @Jamie Hall said, the pressuretrol setting is adjusted not by moving the lever, but by moving  the adjusting screws. On your model, the adjusting screws are on the top of the casing.

    Bburd
  • Hap_Hazzard
    Hap_Hazzard Member Posts: 2,846
    IIt's hard to tell what that indicator is indicating, the way it's bent. I'd turn it down as far as it goes then use a pair of pliers to straighten the indicator at the .5 line and leave it there.
    Just another DIYer | King of Prussia, PA
    1983(?) Peerless G-561-W-S | 3" drop header, CG400-1090, VXT-24
  • ChrisJ
    ChrisJ Member Posts: 16,228
    NHOwner said:

    If the pressure has gotten up to 4 psi without the boiler shutting off, either the pressuretrol isn't seeing the boiler pressure (clogged pigtail, clog in the base of the pressurtrol, clog in the tapping in the boiler) or it is defective -- which is unlikely -- or it is wired incorrectly. The wires are on the correct terminals in the pressuretrol, but is it really in series with the other safeties as it should be?

    The OP is looking at the 0-30 psi gauge. The 0-30 psi gauge does not capture the correct psi. That's why everyone recommends installing a 0-3 psi gauge?
    If the factory 0-30 PSI gauge is showing 4 PSI the pressure is unreasonably high regardless.
    I'd bet the real pressure is somewhere between 3.5 and 4.5 PSI.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • thepiperofseville
    thepiperofseville Member Posts: 12
    OK...

    I removed the pigtail, I flushed the pigtail (it was gross), I resealed and replaced the pigtail, and the pressuretrol. I TESTED the pressuretrol by tilting the arm up (with a pencil). The pressuretrol works, but the pressure in the system has gotten up to 5PSI without it tripping.

    Could the standard 0-30 gauge be wrong?
  • ratio
    ratio Member Posts: 3,774
    Pressuretrols are notorious for their calibration (or lack thereof).

    I don't think you ever answered Jamie, are you pushing the indicator to adjust the pressuretrol (wrong), or using the screws on top (correct)? While the 30# gauge is suspect, I would hope you can either lower both the differential and main; or at least calibrate it.

  • neilc
    neilc Member Posts: 2,785
    you said the pigtail was ugly,
    what about the 90, and nipple, back into the boiler?
    did you do the blow test and have free breathing back into that boiler ?

    if you pull a wire off the Ptrol, and insulate / isolate the wire so the circuit is open,
    the boiler does NOT fire,
    correct?
    known to beat dead horses
  • thepiperofseville
    thepiperofseville Member Posts: 12
    I found a thread that explained how to adjust that TINY hex screw. I blew into the bottom, almost blew a blood vessel trying to get it to click. That told me it was too hard. Found my TINIEST screwdriver I own, gave that guy a turn, blew again, clicked very easy. put P-Trol back on, boiler cut out at about 1.8, which I'm super happy with. As soon as I get a LPG I'll fine tune it to the 1.5, but im just happy its working now.
  • thepiperofseville
    thepiperofseville Member Posts: 12
    Thank you everyone for all your help and guidance. Its currently -3 out and the boiler is purring like a kitten at the appropriate water level and pressure.

    Now I just need to skim and clean the sight glass. Ill wait for a warmer day LOL