Why Doesn't The Pressure Gauge On My Steam Boiler Show Any Pressure? Hint: It Rarely Should

[@erikgreer8794]

Besides all the great information, one of the nice things about your KZbin channel is how quickly you respond to the questions that we ask. I know that you and your buddy “Steamhead“ are busy guys, so I appreciate the extra effort that you make in getting your answers out! Erik in the D

[@kevin7151]

Very informative as always Gordon. You have a great and detailed delivery style that all people can appreciate. I was not aware that the gauge would read 0 or near 0 always. Thanks for the education. Have a good weekend.

[@scott3013]

Thanks Gordon. This got me much closer to the answers I'm looking for!

[@christophermarx631]

Very helpful. Thanks for taking the time to explain.

[@jasonjohnsonHVAC]

As Dan Holohan said...." the Empire State building runs off 1.5 lbs of steam for the whole building. I work on commercial boilers and have seen plenty of process steamers running at 13,15,20,50,100,300 lbs of pressure and superheated steam in excess of 600° steam. I worked with a guy who was the only certified tech to work on ultra high pressure steam. He would tune up the boiler and we'd check pressures......1500 psi and 800°+ superheated steam. Everything was stainless steel and every connection point had to be checked and tested. It was a huge boiler. I believe it was a 150,000 lb per hour steamer.

[@gordonschweizer5154]

Thank you for your story! As to the Empire State Building, the trick there is that there is a big vacuum pump on the return that pulls at least 6" Hg, so the delta p on the steam is over 6 psi. Even so, still pretty low pressure for such a big building!

[@AdrianButler86]

R u stating fact? Im just curious to know im not being an ass. I do know that the condensate is not returned to Con Ed plant for reuse. They don't want it back lol so it's

[@ronpossick]

thanks,i was in the plg business for 55 yrs and did not know about the guage . also never saw a guage with internal syphon. never to old to learn.

[@gordonschweizer5154]

You're welcome! As Ive said, steam gauges with "internal syphons" are usually found broken because the syphons get clogged and can't be cleaned.

[@turbofinance2000]

Thanks, I was always frustrated to see the gauge needle staying at 0, even if the heating of the house was OK. Because of that, I was suspected a leak in the wall.

[@paulkennedy5822]

Excellent and informative as usual Gordon. So I’m trying learn about steam and to dial in my old boiler. I’ve decided that, since all I have currently is the 30 psi code gauge and am, in effect, flying blind, that I would add a low pressure gauge as my first upgrade. It just dawned on me that by adding just a blood pressure bulb and a 1/4” barb fitting to the parts I ordered to Tee that in I can rig up a test jig for my Pressuretrol. Mine seems to be absolute junk. My system cuts out at 3 psi and cuts back in at 2 according to the current gauge. If I turn the screw left even just a 16th of a turn it will cut out at about 2.875 psi and not cut back in at all without intervention. Does that sound like a bad Pressuretrolto you?

[@gordonschweizer5154]

I am glad I am useful to the steam heating community! As to the PA404A pressuretrol, what you are experiencing, sad to say, is its usual hi-jinks. It is a pretty precise control, but it is not very accurate. Taking a step back in looking at your system, have you tried having a tech downfire your boiler a bit? The idea being that the pressure control is a limit control only. If you put less energy into your system, as long as the radiators get hot enough, the radiators will adsorb the steam and the pressure (which can be thought of as unnecessary energy input) will not hit the high limit. Or take longer to hit that high limit, and by then the t-stat is close to being satisfied. In theory, if the energy input more or less equals the energy adsorbed by the radiators (the output), the pressure will never rise above a few oz.

[@paulkennedy5822]

@@gordonschweizer5154 I have been thinking about what would be involved downfiring it. The cycles seem to be very short, something like 4 minutes on and 3 minutes off. It does put heat into the house but I’m afraid it’s not very efficient. The boiler is rated for a .95 GPH firing rate per the plate. My burner has a .85 GPH nozzle. I’ve been thinking of going with a smaller nozzle but am concerned about the consequences. I know I need to test the pump pressure and hope to be able to do that soon. I’m hoping it’s somewhere near the 100 psi it shipped with.

[@gordonschweizer5154]

@@paulkennedy5822 I'm not as versed in oil heat as much as gas, so, grain of salt if you will. That being said, the lower limit of down-firing is usually determined by fuel gas temperature. If you down-fire too low, the water vapor in the flue gasses will condense in your flue and cause it to fail. Not exactly sure what the lower temperature limit is, but it's not much lower than 385*F If you have an exterior chimney, flue gas temps need to be higher to start. I'd consider getting your flue relined (if not done already).

[@paulkennedy5822]

@@gordonschweizer5154 Thank you for the recommendation. Right now I’m in the learning and planning stage. Once I (hopefully) make it through this heating season I plan to have the system thoroughly inspected by a professional with the proper analyzer. I will make sure to have a smaller nozzle on hand to maybe try it. In the meantime I am learning and planning maintenance and potential upgrades to improve efficiency. One complicating factor is that I am investigating installing a whole house heat pump. If that happens, the existing steam system will likely become a backup and, as such, efficiency will not be as important. Of course maintenance and safety will be paramount so, depending on what I find, I may end up addressing the chimney. Again, thanks for the insight.

[@nightone9720]

Hey Gordon thanks for the great video! I've been watching your channel and it's obvious that you know a lot about steam boilers. I have a question. So the company I work for has a client that wanted to get into the business of washing his own semi truck tankers. He needed a system that was able to heat up water quickly so we ended up working with an engineer at a supply house to design a system that could achieve this. What we have is a cast iron low pressure steam boiler that delivers steam to a steam to water heat exchanger. The heat exchanger has a control valve that modulates the steam entering the exchanger depending on water temp. This heat exchanger is actually built into a large holding tank that stores the water for when it needs to be used. When we first started the system it seemed like it was taking longer to heat the water. It did work but they decided to crank up the operating control to 13 psi. I know that more pressure means more steam which means more BTUs but do you think it is really making that big of a difference by turning it that high? I just wanted your input on this.

[@gordonschweizer5154]

Thanks for your kind words! As to your question: I'm sure the engineer got info on the expected load, that is how much water needed per hour and at what temperature rise. As to the proposed system: Someone wiser than me said that a BTU is a BTU. You need more energy to fire the system at higher pressures (and you are dancing pretty close to the safety relief valve limit!) Will most of that energy make it into the storage tank? It should, but I would dial it back to the lowest it go that will satisfy demand. The modulating valve might be too restrictive? Is there a pressure gauge on the downstream side of the valve?

[@nightone9720]

@@gordonschweizer5154 Hey! Thanks for the response! I am glad you asked the question about the valve because the boiler will satisfy on pressure even when running at this higher pressure and it seems to me like the valve is not able to keep up. There is a valve on the outlet and it approaches 9 psi when the boiler approaches 13 psi. The valve uses a 0 to 10 v DC operating range where 0 v is fully closed and 10 v is fully open. Ive only seen the valve fully open with 10 v dc present. There is a steam strainer before the valve and even though the system is 2 years old I believe I should check it for restrictions. There is also a steam vent with a pressure gauge before the strainer and I noticed that the gauge is reading 0 psi which is not correct and the steam vent is constantly letting off a bit of steam. I'm sure that steam vent isn't helping by consistently letting steam escape which can lead to excess fresh water being introduced to the system. Do you think if I replace that gauge that doesn't work along with the steam vent and inspect and clean the strainer and lower the operating pressure on the boiler and it still seems like it is short cycling then it might just be that the valve is undersized for the boiler? I guess at that point I would need to reach out to the engineer and see what went wrong or if there's a larger valve that could be installed.

[@gordonschweizer5154]

@@nightone9720 Please remember, I'm not an engineer - I just play one on KZbin. Most valves have a Cv (coefficient of valve) so you can compare the flow thru different types. You might need a valve with a higher Cv ratio than the one on there currently.

[@nightone9720]

@@gordonschweizer5154 Thank you Gordon. You're wonderful.

[@2pugman]

The plumber and I flushed the wet return and checked the system. I have one radiator at the end of a 2" line that blows water out the new #40 air vent. I have to rotate the air valve to allow the water to drain out for the next heating cycle. The 2" main has a new Gorton #1 vent. The radiator is pitched correctly. Any ideas what's wrong ? Thanks.

[@gordonschweizer5154]

Is the pressure too high?

[@drelkokolito601]

Hi Gordon, I have a Utica Steam Boiler . I have 5 radiator in my house and only 3 of them heat up and 2 stay cool I check the water level and it was ok and also I put pressure control in 0.5 pound and it still no working. Base on your experience what could be. maybe the pressure control, relief Val Ave or the valve steam

[@gordonschweizer5154]

Do you have good vents on your steam mains in the basement?

[@atch_n_sons]

I have a 0-3psig on my IN4 and the needle barely moves. I have been tempted to adapt my Fieldpiece Joblink probes to get a window into operating pressure of my boiler

[@pb7379-j2k]

Get a low-range Magnahelic gauge on eBay. Shoot for a range of 2-5 inches of water column

[@gordonborsboom7460]

There is 27 inches of water column per psi. Half a pound is roughly 14 “. A 50 inch Magnehelic would be appropriate.

[@pb7379-j2k]

@@gordonborsboom7460 he said his 0-3psi gauge barely moves and your recommendation is the equivalent of a 0-2psi gauge? 50”wc is way too much range

[@Lawtown31]

Hi Gordon, question , is the gauge you are showing supposed to get hot when the furnace cranks up? My needle doesn't move, but the body of the gauge gets hot, then cools down when furnace cools down. Please let me know. Thanks.

[@gordonschweizer5154]

I have seen it where the gauge's internal Bourdon tube leaks, allowing a bit of steam into it, but that's rare. There might be a very slight leak at the threaded connection (more likely). It might be heat conduction? Is this a new install? The water seal in the pigtail might not have formed.

[@Lawtown31]

Yes new install, never checked if the old one got hot. No leaks anywhere. I'm thinking heat conduction because when its not heating up, the gauge is cold. Will keep my eye on it. Was just cleaned by the company that installed it 20 years ago, tech said all was normal, he installed it, I bought the part last year from Burnham Supply online. @@gordonschweizer5154

[@user-tk6ih8tp2h]

sometimes my gauge reads as high as 20 psi . there is no pigtail. it just directly connected to boiler. should i bother to replace it? I assume it just screws ito boiler

[@gordonschweizer5154]

I would recommend a 1/4" tee be added between your pigtail and your pressure controller. Then, you can add a gauge there. The gauge that screws directly in the boiler usually fails due to sludge being pushed into the gauge. Best leave it alone for now.

[@TrentG23]

What would cause my boiler to build too much pressure and then blow water out? Just bought a house with a steam boiler from 1985, and came back 1 morning, and there was water all over the floor, and the boiler was off until I added more water. Do I need to replace a pressure valve? Thanks!

[@gordonschweizer5154]

The safely valve might have just been doing its job & there was nothing wrong with it, which was good for you, otherwise....bad day. I would shut the power off, and remove the pressure controller & check the "pigtail" it should be attached to, by trying to blow thru it. If you cannot blow thru it, and if it is made of steel, it should be replaced. If it is brass, you can try and rod it out with 18ga wire. You may need to call someone in. Do not delay, & do not run the boiler until then.

[@mikerefrigeration5736]

I spent like 2 hours today. Watching this gauge on my newly installed steam boiler. Wondering why it wasn't going up in pressure. All the radiators in the house we're getting hot.

[@gordonschweizer5154]

It sounds like your boiler was right-sized or just slightly undersized. Some folks add a 30 oz/in2 gauge to see the actual pressure. It is amazing to see the pressure run up to no more than, say, 4 oz/in2, and all the radiators are hot.

[@mikerefrigeration5736]

@@gordonschweizer5154 nice ill have to remember that for next time. One of my dry returns wasnt getting hot either. I ended up pulling out the vent ( looked like a radiator vent) i tried to blow through it and i couldnt. It got hot right away after i replaced it with a adjustable radiator vent. I set it for 6. What would be the right vent to put on the end of a dry return?

[@gordonschweizer5154]

I might try a Gorton D vent in place of the adjustable radiator vent? If it spits, try a Gorton C.

[@mikerefrigeration5736]

@@gordonschweizer5154 thank you. If you get a chance maybe you can check out my latest video on my first steam boiler, would love to hear your critique ty

[@sambotoo5326]

Hi Gordon . I have my Weil McLain steam boiler , in my 2nd house , I didn’t drain the rusty water almost a year , when I opened the drainage 4 days ago , I find it sucks air inside the boiler , I waited to cool off and drained all rusty water ,still sucking air , the 2nd day the same thing happened. I drained it completely 3 times and still sucking air when I open the drainage spout , I think it may be a return line is clogged from accum’ rust ,can you tell me what it is , please . every devices are working good with no red lamp Thank you

[@gordonschweizer5154]

It sounds like your system is holding a vacuum? I can't see what would cause that from here. Is there a way to let air in somehow?

[@sambotoo5326]

Unless I install a vacuum breaker, by the pressure gage , but why this vacuum coming from , it is 15 yo system , but I neglected completely just year due to Corona time

[@gordonschweizer5154]

@@sambotoo5326 Did you have a one pipe or two pipe steam system?

[@sambotoo5326]

Only one pipe and devised to 2 pipes , one to the front , and the 2nd to the back of the house

[@gordonschweizer5154]

@@sambotoo5326 Your main vents might be shut and not letting air back into your system. They may even BE vacuum style main vents that have "decided" to start working again as vacuum vents?

[@erikgreer8794]

“The Professor“ strikes again! You seem to be using pigtails on a number of your installs that initially bend upwards and make one and a quarter turns, versus what I normally see which are pigtails that bend downwards and make 3/4 of a turn. What is the advantage to using them? Also, who is a good manufacturer and model to look for on the used market for the old style vaporstats? Cheers, Erik in the D

[@gordonschweizer5154]

Thanks! Those pigtails to which you refer are called "270" pigtails for the 270 degree turn it makes. The thinking is that it is less likely to become clogged with slime & sludge because the loop seal is above the outlet of the boiler. If it does block up, it should be a smaller clog and it should be easier to blow out quickly. Honeywell is the only one I know of for reasonably reliable Hg Vaporstats.

[@user-yv5pz4cg5h]

So the gage is basically for safety

[@gordonschweizer5154]

Yes, it's a code thing. It must be able to show double the maximum working pressure of the heating system. For a typical hot water residential system, that would be 30psi max, so the gauge must be able to show 60 psi. For low pressure steam, which is defined as one atmosphere, or 15 psi, the gauge must be able to read 30 psi. But, since December 1899, the maximum day to day Operating pressure for a residential steam heating system was set at 2 psi.

[@Lawtown31]

Thanks. I replaced the old one thinking it was broke. Same result with new one, pointer doesn't move while furnace is fully cranked.

[@gordonschweizer5154]

Do all your radiators get hot?

[@Lawtown31]

@@gordonschweizer5154 Yes every single one , and all to the very end.

[@user-xn4cy8js7c]

An ignorant friend of mine has an old steam boiler in his house which he runs at "about 8 to 10 lbs" according to the gauge. Obviously he knows NOTHING about his boiler! Surprised his house hasn't blown up yet. Am going to add a 3psi gauge to his system after we find the obstructions in his piping...I wonder why boiler makers don't always install TWO GAUGES!

[@gordonschweizer5154]

Remember to check the pigtail for blockages, too.

[@user-xn4cy8js7c]

There is NO pigtail on the gauge which reads to 30 lbs and says "PRESSURE" on the face. In the lower pounds, it has 1/5 lb graduations. The gauge is mounted on top of the old style tricock "can" that the sight glass is mounted to. Note it is an OLD style with only two cocks; one at low water and one at steam. No middle cock, nor hole to mount a middle cock. I think this two liter pop-bottle sized thing is a condenser. It has a pipe for the steam input that runs halfway down the center of the can; had it off the boiler today to repair the LWCO,