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Steam heating issues

ss8295
ss8295 Member Posts: 22
edited December 2019 in THE MAIN WALL
Hello, I have a single pipe steam heating system for a 2 story single family house. Slant fin gxha-160 edpz gas boiler and a total of 8 radiators with all working air vents. 1 main vent on the return line which is a Gorton # 1 and a Honeywell pa404a pressuretrol. Boiler is around 5 years old but not sure if it was ever skimmed when installed. Though water seems clean enough and sight glass water level is pretty solid and not bouncy. Pigtail was recently cleaned and the water in boiler is relatively clean with no mud.

A couple of issues I am having that I can’t figure out is 1. I can’t dial in the pressure to where I need it and 2. A banging radiator that eventually stops working.

For problem 1 I have the pressuretrol set to cut in at .5 and cut out at 1.5. But my boiler cuts out at around 4psi and cuts back on at 2psi. Pressure will rise to 4psi in about 30 minutes cutting the boiler off at which point in 2 minutes pressure will fall back down to 2 psi kicking the boiler back on. Then again pressure will rise to 4psi from 2psi in about 5 minutes. So I have a boiler cycling on and off about every 5 minutes until the thermostat is satisfied. Is this okay?

Also I heard I can further calibrate my pressuretrol. Can someone guide me to which screws exactly calibrate the pressuretrol. I have 2 hex screws right above the diff wheel are those the control?

As for problem 2. I have one problematic radiator which happens to be on the second floor and furthest from the boiler. It was also recently relocated which leads me to believe the contractor probably piped it incorrectly. The problems with it are 1 it bangs. So I raised the radiator and also pitched it correctly. This mitigates the banging quite a bit. But what eventually happens is the air vent starts spilling out a lot of water. I’ve tried a Gorton #6 and maid o mist #4 which both eventually leak water. Surprisingly a Hoffman #40 behaves differently as in it doesn’t leak out the water instead it locks up at which point the radiator stops working. If I unscrew the Hoffman some water spits out of the vent and pressure is relieved as I can hear a bunch of air moving and water gurgling. A few bangs later and the radiator is back working for a day or so until water and/or pressure build up again. Interestingly if I screw on a cheap off brand air vent it seems to malfunction and let’s out a bit of steam. This allows the radiator to stay working with very few small hammering but at the expense of letting some steam vent out.

It’s pretty certain the horizontal piping for this radiator was probably laid incorrectly but I am wondering is there anything else I can do to try and assist this radiator. It seems to me there’s a lot of pressure and air coming into this radiator for some reason and if I can somehow modify the amount of pressure coming into this radiator that it would help. Any ideas?

Comments

  • JUGHNE
    JUGHNE Member Posts: 11,042
    You want your pressure gauge and control on the same clean pigtail. The bottom of the control or gauge can be plugged also.
    Not only the pigtail is to be clean but the tapping into the boiler is often overlooked and clogged. I would start there and be certain that both the gauge and control actually sense the boiler pressure.
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    > @JUGHNE said:
    > You want your pressure gauge and control on the same clean pigtail. The bottom of the control or gauge can be plugged also.
    > Not only the pigtail is to be clean but the tapping into the boiler is often overlooked and clogged. I would start there and be certain that both the gauge and control actually sense the boiler pressure.

    This is in fact the case. Gauge and control are on same pigtail and all necessary items clean.
  • Jamie Hall
    Jamie Hall Member Posts: 23,159
    If the pressuretrol is set to cutout at 1.5 and doesn't until a reliable low pressure gauge on the same pigtail says 4 psi -- it's sufficiently far out of calibration that it's not even a good paperweight. Unless... did you check the opening in the bottom of the pressuretrol? That has been known to get gunked up.

    You also need to verify that your pressure gauge is accurate. Some are not, and the 0 to30 psi gauge -- which is required by code -- may not be reliable at low pressures, so another low pressure gauge should be mounted on the same pigtail.

    Now on the problem radiator -- there is a horizontal pipe leading to it? If it isn't pitched correctly, there's one and only one fix: repipe it so it is pitched correctly. That is likely to be the problem. It may or not be a simple fix.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    > @Jamie Hall said:
    > If the pressuretrol is set to cutout at 1.5 and doesn't until a reliable low pressure gauge on the same pigtail says 4 psi -- it's sufficiently far out of calibration that it's not even a good paperweight. Unless... did you check the opening in the bottom of the pressuretrol? That has been known to get gunked up.

    Well from what I understand my trol is additive so it should cut out at 2psi and kick back on at .5psi. But yea definitely seems out of calibration. Pigtail, gauge and trol were all removed and cleaned. Thing is though I’m more concerned now with whether or not I am short cycling and if that’s an issue. If I lower the pressure that will compound what’s going on now where once the boiler reaches 4psi it cuts out to 2psi for a duration of 2 minutes then cuts back on and builds pressure to 4psi which takes about 5 minutes and this cycle of on and off continues till the thermostat is satisfied.
  • Steamhead
    Steamhead Member Posts: 16,796
    @ss8295 , where are you located?
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    ss8295
  • KC_Jones
    KC_Jones Member Posts: 5,722
    ss8295 said:

    1 main vent on the return line which is a Gorton # 1

    This is surely part of your problem, I doubt this is close to enough. Pressure is a function of the boiler size and venting. If the boiler is over sized (common) and you don't have enough venting (common), you will never run at low pressure.

    How long and what size are your mains?
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    Grallertss8295
  • Jamie Hall
    Jamie Hall Member Posts: 23,159
    Changing your cutin and cutout pressures won't change your cycling much. If any. The big difference will be in your fuel bill: that time spent burning fuel to get to 4 or 5 psi is almost completely wasted money. 1 psi is enough to get steam out to your radiators; anything over that is just compressing the steam to no use.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Grallertss8295ethicalpaulCanucker
  • ss8295
    ss8295 Member Posts: 22
    edited December 2019
    @Steamhead
    @ss8295 , where are you located?

    NYC

    @KC_Jones said:
    How long and what size are your mains?

    I never measured but I’d say my mains are about 40ft long and in 2 different sizes of 1.5 inch and 2.5 inch. I’ve been thinking about swapping to a Gorton #2 as the main vent. Should that be good enough? How can I know if my boiler is oversized?
  • Steamhead
    Steamhead Member Posts: 16,796
    edited December 2019
    Steamhead said:

    @ss8295 , where are you located?

    NYC

    Plenty of good Steam Men there- try the Find a Contractor page of this site.
    All Steamed Up, Inc.
    Towson, MD, USA
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
    ss8295
  • ww
    ww Member Posts: 282
    edited December 2019
    Everyone responding on this thread has given great advice on this subject...all these problems I've encountered as well and solved them using these methods..and more.

    I've used more than one vent on each side of the mains...calculated sizes of all pipes and radiators as well to figure out vent sizes at radiators.

    I'll stress what's been said here again about the pigtail and cleaning of the pressuretrol. I've taken them all apart and cleaned them up ...and they worked fine.

    I'm sure a level will solve pitch issues causing radiator problems.

    By the way is the water level correct in the site glass?...seen radiators filled with water causing no heat more than a few times.

    From what you say you have checked out alot of these issues and things look good...I'm sure you'll zero in on the problem.
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    So today I swapped out the main vent to a Gorton #2. It seems to have made a difference in how long it takes for the boiler to reach 4psi. But not by much. From 30 minutes to now about 45 minutes. I have a total of about 70ft of main and return lines. Should I add another Gorton #2 vent at the other end of the return line?
  • Jamie Hall
    Jamie Hall Member Posts: 23,159
    4 psi is still too much. The burner should shut off long before that.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • KC_Jones
    KC_Jones Member Posts: 5,722
    Couple things to clarify, pressure is a function of boiler size, to system size and venting. Pressure can only build if one of these things is out of sync with the others. Getting to 4 psi indicates to me something isn't quite right.

    I would suggest before going any further and spending more money you calculate the EDR of your system and compare that to the boiler size so you have a baseline for what is possible.

    If the boiler is too over sized you are only going to get so good on the pressure and the safety control (pressuretrol) becomes an operating control. That said with 40' of main I'd say you will need more main venting. To add additional venting we usually recommend doing an antler arrangement. If you search the forum you should find plenty of examples.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    ss8295ChrisJ
  • ww
    ww Member Posts: 282
    have you checked the pigtail for buildup..have you checked the pressuretrol for buildup...if the gauge says 4 lbs...it shouldn't if pressuretrol is working...maybe clogged...the empire state building needs less than a lb to heat the top floor...don't dismiss the simple basic checks...does your gauge have oz increments?
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    edited December 2019
    > @KC_Jones said:

    I would suggest before going any further and spending more money you calculate the EDR of your system and compare that to the boiler size so you have a baseline for what is possible.

    How do I go about calculating the EDR size? My boiler specs are as such

    CSA INPUT (Btuh) - 160,000
    D.O.E. CAPACITY (Btuh) - 130,000
    NET AHRI STEAM (MBH) - 98,000
    NET AHRI STEAM (SQ. FT.) - 408

    I have about 70’ of main and have 6 radiators in use. Originally there were 9 radiators hooked up but 2 of them have the valves closed (one of them because piping leading it it is incorrect and it bangs and a second due to the room getting too hot) and another was removed when the house went under renovation and it was needed. I’ve tried running the system with the shut off radiators opened with no change in pressure.

    @ww have you checked the pigtail for buildup..have you checked the pressuretrol for buildup...if the gauge says 4 lbs...it shouldn't if pressuretrol is working...maybe clogged...the empire state building needs less than a lb to heat the top floor...don't dismiss the simple basic checks...does your gauge have oz increments?

    Yes everything was recently cleaned so it should not be clogged. The gauge is a standard 0-30 psi gauge. Funny thing is it always reads 1psi even when the boiler is off. Not sure if normal. Either way even if the gauge is inaccurate it seems pressure builds up and the pressure trol kicks in to shut off the boiler. This cycle of on and off keeps continuing until the thermostat is satisfied. I’d rather have it where pressure never gets high enough for the pressure trol to be activated. I may have a oversized boiler.
  • ww
    ww Member Posts: 282
    those gauges aren't fine enough increments for my liking. the purpose of a main vent is to clear the cold air out of the main pipes quickly...you say it takes longer to get heat up...should be less time now...your vents on the radiators...how did you size them...?...if the boiler is totally off..and gauge reads one lb maybe the dial or pointer has shifted...can you take the cover off and push it to zero when the system is off...find the model of the pressuretrol...research the instructions and read them...some of the problems in some of these resulted from the pressuretrol being leveled the wrong way...i still keep thinking regardless of the size of the boiler ...the boiler should cut off...it would be nice to look at the gauge and see when boiler cuts in or off...minor details are a nuisance but must be checked..was there any clog in the pressuretrol at all or was that not checked?
    ss8295
  • KC_Jones
    KC_Jones Member Posts: 5,722
    https://www.weil-mclain.com/sites/default/files/field-file/Weil-McLain_BoilerReplacementGuide_WM1905-web.pdf

    Start on the bottom of page 9 and you can measure and then calculate the EDR of your system. Removing and closing off radiators will exacerbate the over sizing problems.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    > @ww find the model of the pressuretrol...research the instructions and read them...some of the problems in some of these resulted from the pressuretrol being leveled the wrong way...i still keep thinking regardless of the size of the boiler ...the boiler should cut off...it would be nice to look at the gauge and see when boiler cuts in or off...

    So I have a Honeywell pa404a. Additive pressure trol. Level seems to be fine. I have a feeling it’s calibration is just off. I’ll see if the dial on my gauge can be pushed back when boiler is off. But according to my gauge right now it takes about 45 minutes from cold start to build up to 4psi. The boiler then cuts off and pressure drops to 2psi which takes about 2 minutes. Then boiler kicks back on and then since everything is already pressurized it only takes about 5 minutes for pressure to build back to 4psi cutting the boiler off again. This constant on/off cycle I’m not a fan of. Oh and the radiators I’ve sized the vents to the size of the radiators. So smaller radiators have maid o mist #4’s and bigger radiators have maid o mist #6’s.

    minor details are a nuisance but must be checked..was there any clog in the pressuretrol at all or was that not checked?

    Pigtail, pressuretrol etc have already been taken apart and cleaned. Pigtail was barely clogged when taken apart and it probably wasn’t cleaned for years.
  • Jamie Hall
    Jamie Hall Member Posts: 23,159
    You may not be a fan of that on-off cycle, but it is a symptom of an oversized boiler. As I said above, you shouldn't be allowing the system to get to 4 psi -- 2 psi for a residential system is the maximum it should ever get to. Adjust your pressuretrol to accomplish that. That will not change the on-off cycle timing much, but it will save some fuel.

    When the boiler runs for 45 minutes at a stretch to get up to where it cuts off, are you coming out of a setback? In reasonable weather in northern areas, it isn't common for a boiler and heating system to have to run that long to maintain a steady temperature (think of it this way: if the design minimum outside temperature is 0, and the system is sized for that, at 35 outside it should only run for half an hour out of every hour). Coming out of a setback is a big load for any heating system.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ethicalpaul
  • ss8295
    ss8295 Member Posts: 22
    > @Jamie Hall said:
    > You may not be a fan of that on-off cycle, but it is a symptom of an oversized boiler. As I said above, you shouldn't be allowing the system to get to 4 psi -- 2 psi for a residential system is the maximum it should ever get to. Adjust your pressuretrol to accomplish that. That will not change the on-off cycle timing much, but it will save some fuel.

    I’ve tried adjusting the ptrol. It’s set at .5 cut in and 1.5 diff. It’s a additive ptrol so from what I understand it should cut out at 2psi and come back on at .5. But it doesn’t behave as such. Unless it is behaving as such and my gauge is just giving inaccurate readings.
  • Jamie Hall
    Jamie Hall Member Posts: 23,159
    Could be either the gauge or the pressuretrol. Is it the required 0 to 30 psi gauge? They are none to accurate at low pressure. You can put a 0 to 5 psi gauge on in addition to check -- not a bad idea.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    ss8295
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,452
    Your boiler is rated for 408 EDR. If the boiler output is much larger than the installed radiation you will build pressure which is unfortunate as you don't want to build pressure. It wastes fuel and causes short cycling.

    Increase you venting. As far as the banging radiator that is likely caused by running too much pressure and a pipe or radiator that has improper or not enough pitch.

    Re calibrate or change your pressure control.

    To prevent short cycling you may have to adjust the pressure control to cut in at the lowest possible pressure, .5psi or lower Then play with the cut out. 1.5 cut out is high enough but you may want to raise it to prevent short cycling if your boiler is oversized.....but raising the pressure won't help the short cycling much much
    ss8295
  • ww
    ww Member Posts: 282
    in some thermostats there is an adjustment for various systems such as boiler...hot water...steam...etc...is your thermostat set up properly if this is applicable?...once you figure out a gauge that has low increments you can match up the gauge with the cut off...some of these older pressuretrols may lose spring pressure a bit and you may have to play with the settings to compare the cut out and cut in pressure on the gauge with the unit...this is all well and good if you have the time to do it..and the skill to do so...but most people would just change it all out with new parts...but once you get it going right you may just do that so you won't have to guess or if someone else needs to set it they won't know you did....you have to be near the boiler to do this because once it cuts off the pressure on gauge will drop off fast.
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    Thank you everyone for the feedback. So I did some calculations and it seems as if I do in fact have a oversized boiler. I have about 50,000 btu of maximum radiation. Taking into account the 2 radiators that are shut off brings my radiation output down to 32,000 btu. My boiler is rated at 98,000 btu! But here’s the thing, I have about 70ft of uninsulated but painted main piping. How much btu can that account for roughly?
  • KC_Jones
    KC_Jones Member Posts: 5,722
    70' of 2" pipe is about 44 EDR, so not much.

    BTW typically steam is rated on Sq Ft of radiation not BTU's and compared to the Sq Ft rating on the boiler. What was the EDR number for your system?
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • ss8295
    ss8295 Member Posts: 22
    > @KC_Jones said:
    > 70' of 2" pipe is about 44 EDR, so not much.
    >
    > BTW typically steam is rated on Sq Ft of radiation not BTU's and compared to the Sq Ft rating on the boiler. What was the EDR number for your system?

    How do I calculate the EDR? The Weil McLain guide demonstrates how to get btu of each radiator.
  • KC_Jones
    KC_Jones Member Posts: 5,722
    EDR is the square feet of radiation per section. The sq ft is compared to the sq ft on the boiler plate and that is how the boiler is sized.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • ww
    ww Member Posts: 282
    edited December 2019
    Keep in mind that this site has a wealth of information and that researching the site itself can find answers that have been asked and solved before...here is some information posted previously on this site that may help a bit on the oversized boiler question:

    https://forum.heatinghelp.com/discussion/143226/oversized-boiler#latest
    ss8295ethicalpaul
  • ww
    ww Member Posts: 282
    edited December 2019
    ss8295 said ....Also I heard I can further calibrate my pressuretrol. Can someone guide me to which screws exactly calibrate the pressuretrol. I have 2 hex screws right above the diff wheel are those the control?

    this instruction manual will show you how to set this pressuretrol and adjust the screws and more.
    ss8295
  • ss8295
    ss8295 Member Posts: 22
    Btw guys what’s like the smallest air vent on the market?
  • gfrbrookline
    gfrbrookline Member Posts: 753
    Gorton No. 4
  • ss8295
    ss8295 Member Posts: 22
    edited February 2020
    Maybe someone can figure this out I have a peculiar situation. So I have a rad that bangs on initial start up. I’m almost certain it’s due to incorrectly installed horizontal piping in the floor when that rad was relocated.

    Now here’s the thing. If I install a Gorton air vent size D the banging goes away. But it seems like the Gorton valve for some weird reason doesn’t fully close on this rad. I say it seems like it because I don’t see any steam shooting out but I hear a slight hissing from the vent even after the rad is fully hot. If I put my finger next the hole I feel a slight bit of moisture on my finger and hot air. The Gorton doesn't behave this way on any other rad in the house only on this one. Also the size D creates a vacuum in that rad when the boiler shuts off. I don’t know if that vacuum helps in assisting taking water away and so the rad doesn’t bang upon next fire up. I tried a cheap vent on this rad, it also wouldn’t stop leaking steam but this time it was obvious as I could smell the steam and also see a lot more moisture. This cheap vent also resolved the banging.

    If I install any other vent, I’ve tried Hoffman and maid o mist, they operate as they should and close and stay closed but the rad starts banging again. What’s going on here?
  • PhilKulkarni
    PhilKulkarni Member Posts: 70
    I have one of the same symptoms- short cycling after an initial 35m boiler run. With the same PA404 set at the lowest cut-in in my case 1.4PSI (though the wobbly slider shows 0.5 PSI) and the additive diff set to its lowest at 1.0PSI my boiler cuts out at 2.4 PSI. From 1.4-2.4 PSI it takes approx 2m at 20 sec.

    My boiler was installed 7 yrs ago in the NYC area by a boiler man who told me it was slightly undersized (BTUs/hr) relative to the one it replaced. Yet he claimed the cycling was normal and replaced all 8 vents with various size Maid O Mist brand. I had vari-vents before that. The cycling was unchanged.

    I have 55’ of 2” pipe heating the front of the house and another 45’ heating the back of the 3 story house. The pigtail and the bottom of the trol are clean and the original newer trol was replaced 3 years ago with the current one because it was very inaccurate. The gauge reads 0-5PSI and seems to be well calibrated.

    On each of the 2 headers I have Big Mouth main vents which only open during the initial warm up but are closed while the boiler recycles.

    I have increased the cycle time by inserting a time delay that commences at cut-in and keeps the boiler off for 2m 25 secs of off time to the boiler which now stays shut for 70 secs after the pressure drops to 0.

    To sum up, after the initial 35min run the boiler runs for 3 mins and is off for 4mins and 45 secs. My heating bill is lower since I installed the timer.

    Hope this helps.



  • You may still be needing more main venting capacity-what pressure shows during the venting phase, while steam is starting to be made?
    The boiler certainly behaves as if it is oversized, even though smaller than its predecessor.
    What sort of thermostat is in charge, and is it set for steam?—NBC
  • PhilKulkarni
    PhilKulkarni Member Posts: 70
    Thank you Nicholas for your suggestion. Wondering if I should add another Big Mouth in each of the two circuits or something with a lower venting rate. The 55’ run has 2 largest rads which suck air loudly at the end of the cycle on cold days. So installing one here first might make sense ? However, as I had noted earlier these vents are silent after the cycling starts and remain so when the stat shuts down the boiler. Not sure this is normal and if not then whether adding more venting that only works during the start up will help.

    The pressure at the beginning of each cycle is always zero because of the timer setting and cuts out at 2.4PSI in just under 5 mins. So about 9 cycles/hr and up to 11 on cold days.

    I have a Nest stat.
  • A big main vent should open up fairly quickly, after the steam collapses into a vacuum, at burner shutdown, and allow air to flow back into the system, reducing the amount flowing into the radiator vents—NBC
  • Jamie Hall
    Jamie Hall Member Posts: 23,159
    With the Nest thermostat you may have incurable problems Try disabling all of its smart features first. Nests do not play well with steam and hot water heat, never mind radiant.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Gordo