It never did this before......

"I found the gas pressure low, at 2.9" WC and raised to 3.57" WC"

I'd bet that the pressure was lower than that, when another contractor turned it up to 2.9". That would explain things.

Yeah.........A couple of conditions (improper) that could allow that to happen have been identified. Believe the homeowner, but figure out how to go forward.

No main vents? Should have them -- but you may have difficulty persuading the homeowner to install them. Worse, they won't help the problem with the boiler cycling on pressure after 15 minutes much.

However, @Paul48 's comment may indeed explain things. If the pressure was low, but the burner was operating more or less properly, your BTU input was also low -- the poor thing had essentially been downfired, and might not have been able to produce rated -- or even close to rated -- output. Which would explain a lot.

As the the radiators not being as hot as they were before, without an actual measurement which you don't have, all you can do is smile sweetly and go on to something else.

I suspect @ratio is spot on. Before the boiler was serviced, the pigtail was clogged and the Pressuretrol never saw the actual pressure so it just hummed along. That also explains the reason the radiator vents hissed. Pressure was way too high and the gauge, which I bet is a 0-30PSI gauge hardly moved. They never do at anything below 7 or 8 PSI. Everything got toasty hot!

If you can 2 stage the gas valve, that may solve all these issues. That will, however, be a tough sell.

By all means lower the gas valve pressure to the minimum amount possible, taking that the spec wc is net btu input, and proportionally down to as close to attached edr as you can with good combustion. Def to 2.9 wc you found first, and perhaps even lower. This would be the solution that's only time and no supplies. Then, see if the thing would run without cutting out on 1.5-2.5 psi. Then raise the psi some more and call it fixed when you get it not to shut off... This is what was happening prior to your involvement.

From what's been described and others' suggestions, the boiler probably just built pressure and fought lack of venting with pressure. Could habe been clogged pigtail, broken trol, lower gas pressure... or a combination of the above... who knows. How it's now eating more fuel is by cycling on lower pressure which takes longer to satisfy the tstat ("rads not as hot"). I bet the "rads are not as hot" means they were piping hot from all the pressure which compressed the system air before it had a chance to be expelled from rads' vents.

Then, show the home owner what's going on and what should go on, and walk away.

That's a tough one...

Hello everyone! I am the homeowner.

-Boiler was drained numerous times but never skimmed
-the wet return line is cold following after the burning hot Hartford loop and for approximately the first 6 plus feet of wet return. The wet return line is Cold next to the boiler and the farther you get away from the boiler, the return line is scorching hot-Seems pretty odd to me. No one has had any explanation for that yet.

I banged on the huge nut with a hammer that connects the pipes and on the wet return line pipes and it got hot!!! (Desperate times call for desperate measures) I asked one of the plumbers to take the pipes apart there after the Hartford loop- the wet return line- I was banking on something being clogged near there- I was wrong.

And without me doing my hammer trick, the first approx 6 feet of return line stays cold- even after the boiler is running for a long time. On its own without the hammer it won't progress beyond room temperature but usually it actually stays cold to the touch.

Mike set it up to drain the return line into last radiator in garage and dirty water came out but that was that. Could wet return still Be clogged near the boiler where it stays cold?

-combustion analysis (was fine)
-wet steam??( I don't understand this) how do I know? What is wet steam? The air vent in the final bedroom is gurgling (also new behavior) does this mean that my steam is guilty of being wet steam?
- overfired boiler- now being addressed hopefully
-pigtail and pressuretrol- is it representing reality or too much/too little?
-water ph lol

Aside from Mike, all of the people who came to my house tried to solve the issue by raising the pressuretrol- I argued with them repeatedly about this. I even quoted Dan when he describes a "hapless" person who comes along to do this. Here is what happened- whatever they raised it to- according to that pressuretrol- it would reach the pressure within about 15 minutes and shut down and then short cycle from there. It short cycles every 2 minutes and when one person set the psi (cut in at 3 or 5 and cut out at 7- it would short cycle every 3 minutes). Raising the pressuretrol did not fix the short cycle it just added an extra minute before it short cycled and broke the air valves on the radiators.

Almost every supposed professional that came here told me that everything is running "exactly as it should." This was following them watching the boiler repeatedly short cycle. I called **** on that and all of you have thankfully Confirmed that for me.

All the air vents are now vari-valves and Mike adjusted them.

The water in the glass is not surging.

Another company-approximately a month ago-A cleaner was added and within an hour it went from green to dirty brown. The boiler was drained a couple days later so I do not know if the cleaner even worked or not? I do know my water was cleaner before my tune-up and before this cleaner adding episode. It is now clear again.

Called company who did tune up to come back- volatile individual who screamed "we just changed the glass, we didn't touch anything else, the boiler water is supposed to be dirty- this is not my problem." I don't know if I can believe that or not-it's basically a complete unknown factor- what actually occurred during the tuneup.

The next company I called discovered the relief valve was clogged. I always almost always drain water weekly so the fact that it was clogged enough to not work when it was eventually checked was alarming to me.

when the individual who came to "tune up" the boiler in October said it was running perfectly was odd to me- I would hope he had checked that? And if he did and it got clogged when I have barely got to even use the heat this year- I'm perplexed.

I look at the pressuretrol as a check on the boiler- the fact that the boiler is running off of it constantly is definitely a problem that I am not comfortable keeping this way. I am happy to add main valves and do whatever is in the best interest of the system in the future but first I want this to be figured out because I don't want to do all of that and have it still not work. It worked for 7 years (perhaps unsafely or with screwed up settings) without main valves- I understand this was setup because of coal in the past and this system is archaic and I should put main valves on- but why now? If it gets to the point where I need to move on and fix the problem- I hope that adding the main vents fixes it but I'm not ready to give up on making sure I first know what is actually happening. I don't want to treat the symptoms without knowing what the problem actually is.

Another individual let the first/last radiator (garage) let out the steam at 3-7 psi without the air vent on for approx 10 minutes- it filled
Mine and my neighbors yards with steam (facial anyone?) and guess what- yes it was still short cycling- is that helpful? I sense that's important information but I don't really know. Shouldn't it have stopped short cycling while clouds of steam Were emitted from the radiator with no air vent in the garage?

Is there any chance that this pressuretrol
Could be getting tricked? Or falsely triggered? It thinks it has that much pressure but it doesn't? If it really is building this much pressure this quickly- I don't want to just live with it. (I have my original pressuretrol (some said it was not working and some said it was) back on because the replacement one couldn't be set below 2
PSI- gotta love it) the boiler was rapid cycling with the other pressuretrol as well which points to the pressuretrol probably not being the problem.

Could there be water stuck in the radiators? And if so could this cause the boiler to build so much pressure so quickly and short cycle?

Installed the nest thermostat a month after the tuneup. I was getting confident it was going to be this since it was installed before we needed to use heat but after the tuneup so I put my old Honeywell back on to test my theory- nope not the nest. It short cycles the same regardless of thermostat. Nest even sent someone here to check out the situation. (This company is excellent, they truly care about their customers and perfecting their product). All the wiring is correct with the control etc.

The radiator in the bedroom (final stop) is gurgling with the new air vent. It never gurgled in years prior. It's like a rapid fire gurgling machine gun.

I also have heard water rumbling/boiling while in the basement- I think it is the boiler but it sounds odd. I had never heard this rumbling before either. I have only personally witnessed it a handful of times, one time it was while someone working on the boiler and he got totally freaked out and shut it off and called His boss to come. His boss had no idea and guess what- he wanted to raise the pressuretrol. La la la

Why is it building so much pressure so quickly?! This is on my mind everyday. It seems to me it could go to 15 if the pressuretrol wasn't on it to stop it or the relief valve eventually.

Most of the valves were physically cracked when I removed them and replaced them all With vari-valves. That is what I have on all Of them now. Although- I had Hoffmans originally and have been thinking of buying those again. Could that possibly help? Or long shot?

MilanD- what is 2 stage the gas valve? And why a tough sell? I googled briefly and it sounds wonderful if this doesn't get solved via another route.

Forget locker room talk- it's all about boiler room talk. I hope it's okay that I joined in.

Yes, I am aware of how long what I just wrote was. I apologize in advance if I repeated myself. Steam heat issues can really make an almost sane person go a little crazy.

As of now if I am understanding correct- lowering the gas pressure and raising the pressuretrol to see if that stops the short cycling is the next move? The underlying theory is that the tune up person turned the gas up and the pressuretrol down which caused the short cycling even though he denies touching it.

Is it possible that lowering the gas pressure could help without raising the pressuretrol?

Do you think I should buy Hoffman or some other air vents too? It's hard for me imagine that this is a venting problem after watching all that steam fill the backyards and it still Short cycled. I know that I only have limited Knowledge so please bare with me if my ideas up above make little or no sense - I started thinking that I was alone on this and going to have to figure it out myself so I have spent most of my free time researching all
Of this. I have become fascinated as a side effect and am interested in learning and trying whatever ideas all of you experts come up with.

I miss the good old days when the boiler was satisfied by the thermostat instead of the pressuretrol.

Mike, Thank you for posting this on the forum. I appreciate you taking your time to do this. To everyone else who has taken their valuable time to try to help as well, it means more to me than I have words to express- Thank you all so much.

Whew! Sounds like you've had a hard time of it. The good new is: we're here to help! There're some really smart people here, we'll get it figured out.

I do understand that Paul. I think you have given me good advice as well. I will try to slow it down and will follow all of your leads. I feel so lucky to have all of your help. You are all very generous.

Please let me know what else you need.

I thought I had attached them already. Oops

Pics galore

My thinking approach to this was to answer what could have been going on in the past that the system didn't cycle on pressure and get it back to that state.

I'm not versed in all the ins and outs of various boilers but have spent, like you, massive amount of time figuring and greening our boiler operations as an end user, and am now somewhat of an aficionado.

Oversized boiler and unvented mains will cycle on pressure unless 2 things happen: sky high op psi (pressiretrol set high) and/or combined with the lower btu input on the burners (downsizing of the boiler by lowering btu input via lowering of gas valve pressure, essentially, simmering the fire down as steam boiler is nothing more but a cast iron pot on a stove burner).

What was your system like before the 5 different boiler people had worked on it is anyone's guess. From your orig description (piping hot radiators) and from what Mike posted he's done, looks like boiler was most likely downfired. Maybe inadvertently, or this may have been done in the past by someone who knew what was going on.

Years ago we had several burners removed on our grossly oversized commercial boiler (1.1 MILLION BTU input). Boiler ran fine, we had the heat, and op pressures were in 2-3-4 psi range, if not more. I wasn't aware or understanding any of it 10 years ago... Point is, big oversized, the boiler was underfired, op. pressure was a bit high, and all was fine as far as I knew. I can't tell if it cycled on steam, but I think it must have. Our gas bills were ghastly.

I'm not understanding your pipes being "cold" 6 ft from the boiler in your wet returns and that whole business. After running for a while, returns, wet and dry, will be hot. 200F degree hot. If you are now cycling on pressure, not heating as well AND you see water from the rad vents, your returns indeed may be plugged, condensate is filling the system, rads and pipes, steam is pushing it out of vents and op pressure is building quickly. Water is being added by your auto feeder, and eventually you will completely fill the system. You are - waterlogged.

If indeed your returns are cold - there is your explanation for the whole thing.

The radiator in the garage is of concern. It would appear that someone was trying to scavenge heat from a return. I'd think that it would be plugged, at least partially. It also interferes with maintaining 28" to the water line, which adds the pressure on the return side, so the condensate gets back into the boiler.

Hot water from the Hartford loop can be backing in from the boiler pressure, the equalizer pipe, and the water column pressure, as well as jusy metal heating passively down the run.

Check out that wet return pipe for a clog. This clog may be coincidence at this time and not a causal issue of all other pressure/cycling/boiler size problems, but is adding to, esp. with water coming out of rads.

Harford loop will hold water in the boiler. Drain the wet return and see if hot water starts coming out. If it's plugged, it'll stop draining water after the plug. It may take a while to drain if it's plugged up, but I'm assuming its most likely obstructed and not 100% plugged up so you will eventually get a drizzle of hot condensate.

Op pressue is another matter and should be addressed after pipe plug has been cleared.

Also, check the slope on the steam mains: they should drop down away from the boiler at least 1" for every 20' of horizontal run.

Just make sure you check the combustion numbers at high and low fire AND the flue temperatures - don't want condensation in the chimney.

Bob

Thank you for all for taking your time to help me. Does anyone who is confident they can help me want to come help? I am happy to pay you. I'm in queens, NYC. If that is not able to happen and i am on my own with it- i am handy and strong and can borrow my neighbors big pipe wrench etc but I would kind of need a step by step guide in order to do it myself. I am overwhelmed by this but am determined to get this taken care of one way or another.

I already changed the pressure trol as you advised Fred. Thank you.

From what I understand, draining the boiler and wet return lines and then flushing the wet return lines is the first thing for me to do. I don't even know how to do that. That's embarrassing to admit- are there instructions anywhere that you can direct me to?

I am going to reread and study everything that everyone wrote. It's a lot to take in, so many smart ideas and good questions and impressive observations. I am going to try to start Monday with draining and flushing the return lines unless someone wants to come here, take pity on me, and do a "case study" and get paid for it - I can dream- right?

Thanks again, so much.

Buy a copy of "The Lost Art of Steam Heating', it's great read and a great education.

Bob

There are several very good men in the New York area. Look under Find a Professional under New York.