The main is hot, the radiator is cold, and the heating company can't figure out why.

It looks like the header may be too small. They made a drop header but it looks like the actual header may be smaller than what is required in the manual. Because of that tee arangment between the header and the mains there will be a lot of condensate dropping in to that header, that may be gettign pushed up in to the mains instead of draining to the equalizer.

(get the manual for the boiler from Burnaham's web site, look at the near boiler piping in it. they did a drop header which probably won't be in the manual but that is better than a standard header, but look at the pipe sizes and the names of the parts)

Hello @bmearns,

"I keep trying to hint to the techs the only thing that makes sense to
me: there's a "clog" preventing the steam from getting into the
radiator. Maybe sludge build-up, maybe the service valve is bad. I have
no idea, but it just seems like if the steam is getting there but not
getting in, there's something blocking it."

My guess is your blockage (if you want to think about it like that), although it would seem counter-intuitive is air trapped in a place that the system can not purge it properly. The steam has to push the air out. I believe this may be due to the wet return not properly isolating the drips (vertical pipes against the wall) from the radiators. If condensing steam in the drip pipe creates a lower pressure than the radiator and its vent the steam will go there instead, heating the basement instead of the living space as desired.

Sadly, it seems like your contractor does not know how to troubleshoot this situation and if they did, they would have maybe done the install correctly in the first place. The more you know about your system and its proper operation the better off you will be, now and in the future. I don't think anyone here expects you to learn it all in two days, just keep learning.

Based on the photos posted, I don't see how the steam is getting into the returns. The harford loop appears to be below the water line and is obvioulsy above the returns as shown in the photos. So if the steam is closing the vents, it's coming from the header end of the main and the discussion to the alternative I feel is a distraction.

There is an obvious lack of main venting. That vent would work well on a radiator, but in my opinion has no business as a main vent, even though it's marketed as such. You need at least a Gorton #2 vent on each main, and maybe more. A single Gorton #2 vents at a rate 10x that of what you have.

You want those mains to fill with steam as quickly as possible. From header hot, to main vents hot and closed should take 5 minutes or less. The whole time that's happening the runouts to radiators should remain mostly cold/cool. At that point all radiators will have steam available and the system can be balanced with the radiator vents.

I'd also be curious what radiator vents they put on. Some of those can be quite aggressive and amplify an issue with a single radiator, due to lack of main venting. If they used the same size on all radiators, you most likely won't be able to balance the system using those.

But if MadDog, JohnNY or EzzyT will work in your area, any of them can sort it out. It actually it a lot less of a disater than most but they missed a couple details and one or more of them is throwing the whole thing off.

You may find this article interesting.

https://heatinghelp.com/systems-help-center/what-causes-water-hammer/

I would do the pipe insulation myself and save $$$, not hard to do. However before insulating check the pitch, correct any issues and verify the pipes are properly supported.

As a crude timing reference for you (our systems are a bit different). I let my system cool for about 45 minutes. closed the valve to the main vent. 37 feet of one insulated main. The boiler got steam to the begining of the main in about 2 minutes, then very close to an additional 5 minutes for the main to heat to the far end. The 5 minutes is normally less with the main vent working.

If all the runouts are piped this way there is probally not much water puddling in the main unless there is a serious sag or just no pitch between runouts.

The pronlem is once the installer has your money you will be last on his things to do list and at some point you will drop off that list. I can tell you if he knew what to do he would have done it, he doesn't and now he's stumbling around trying to fix it.

The number of real steam guys shrinks every year and that forces us homeowners to understand how it all works so we can assist the heating guy while he's trying to figure 'why did i accept this job"?

I keep going back to the fact that you say everything was "working well" before the boiler change. Would you or your installer happen to have any pictures of the original boiler and piping??? Would you even know the original boiler make and model vs the current one? We can point out numerous things that are "wrong" with the current system as you have it but other than potential water level which Jamie has been trying to get at I don't know what else has or hasn't "changed" as a result of the boiler install.

1. Can you verify at least that both returns tie in below the min water line back by the boiler (arrow 3 in the below picture)? If not there will be some discussion and even if they are below near the boiler but further up the return line they are above water level then there will be also be discussion. However, if the entire return is below water line then each drip is essentially "plugged" from the standpoint of being a path to drive air out back through an unclosed main vent. That said there are systems with drips tying into main extensions well above the water line that work fine (like mine). In this case when the steam is advancing air can still only escape the system two ways, via the main vents or the radiator vents. If steam reaches the tee at the end of the runout and the main vent is still not closed then the steam has a decision. The path down the drip, through the return toward the main may be less resistance if that drip to return junction is not under water. That said we shouldn't (in most cases) see steam at the end of the runout before the main is closed if the main is properly vented. I actually did move my main vents from the ends of the returns to the ends of the mains due to this issue since I had a very short "loop" off of one of my mains where steam could travel 4 feet down a main, enter a drip from a radiator just above the boiler and travel 4 feet back to the main vent at the end of the return. That would occur before 3/4 of the 30ft of that main got steam. That was solved by moving the main vents. I mention this only to illustrate that steam can take "a" path through the drips and a "dry…" return back to the main vent. In your case assuming you do not have a sag in a supply line blocking steam with water you may be able to resolve your issues with just increasing the main venting so the main vent is closed well before steam gets to the drip tee on a runout. You need to do this anyway even if the immediate problem resides elsewhere so might as well go ahead and do it. Start with at least a Gorton #2 on both.
2. Couple observations on the piping. Looking at the relative position of the main vs the floor joists at the boiler (arrows #1 in picture below) vs out toward the ends (second picture) it appears your mains are counterflow (slope upwards as move away from the boiler). Can we assume they always were and that they didn't get repitched during the boiler install (back to the "before pictures"🙂? There will be a lot of condensate flowing back down those mains which I think the experts would tell you should have a drip of their own back closer to the boiler. I have a bull head tee in my (working) system like yours (didn't get involved here until that was all done…) but my mains are parallel flow. I would imagine with all that condensate in your situation the bull head coupled with higher steam velocity from what appears to be an undersized header (arrows #3) could cause some detrimental effects. Also, the pipe I have a red arrow pointing to in the 2nd picture hopefully it pitches toward the return and not toward the main. (of course this wouldn't have changed just due to the boiler install…)
3. Insulating may help some and eventually you will want to do it but I wouldn't insualate until the root of the problems are fixed. Harder to check for sags, pitch and steam advance once insulated.

I also noticed the steam mains above the boiler seem to look counterflow.

But they are perpendicular below the floor joists and other steam piping is up parallel between the floor joists.

How about some pictures of the end of the pipes coming right from the boiler, before they change and turn 90 degrees between the floor joists?

Could the installer pulled those mains down to make them pitch down towards the boiler?

@bmearns Could you delete your payment values. That is not permitted on the forum. You can talk about what you pay for "stuff" but not what a contractor is paid for a job in my understanding.

Another possibility is it may be a hybrid of parallel flow and coutner flow. There may be a section in the middle that is the high point and condenstate flows toward the boiler and toward the returns in opposite directions from that point. With that weird tee if there are any radiators on the counterflow section (if it is set up that way) it is especially imortant that there are drips before the boiler to remove the condensate before it gets caught in that tee. Are there perhaps drips further out that we don't see that are now above the water line?

You can put an app on your phone that makes a reasonable level.

bmearns said:

Well, they finally sent someone out to actually measure the radiators. He wasn't familiar with the term EDR but he did have some handy dandy book that gave him some charts and formulas and he came up with the required BTUs and found that the brand new boiler was undersized. So they're getting us a new new boiler to replace the old new boiler.

In all seriousness, we can help you calculate this to double check. It's super easy to do. And the fact that you say he didn't know about EDR is a red flag the size of Texas.

I'm with Paul on this one and undersized boiler is rare and in my opinion highly unlikely.

If it is undersized, great you've confirmed things and they will change it out. If it's not undersized they will change everything out, you will still have all the problems you do now, and the new problem of an oversized boiler.

It would have to be grossly undersized for your problem to be size. If it is a little undersized it might cause a little bit of a balance problem.

I don't remember, do you know what size the old boiler was? Unless this is significantly smaller and it was the correct size, once again, size isn't the problem.

https://www.weil-mclain.com/sites/default/files/field-file/Weil-McLain_BoilerReplacementGuide_WM2012-web_0.pdf

There are more options in this one, start on page 9.

They don't know EDR, the obviously don't know venting, I'm sure the list of what they don't know is longer than what they do.

I would trust exactly zero of what they say. I'd say I have a better chance of diagnosing your problem than they do, without even coming to your house.

EDR, is like the very first thing anyone learns about steam. And to elaborate further, EDR is a thing for hot water systems too. This is an extremely common thing.

If you went to a mechanic with your car, would you trust them if they said they didn't know what wheels were? Yes that's where you are with this system right now. EDR is like the wheels on a car, seriously.

Let's get a proper EDR calculation and see where you are at. It may be undersized, but even if it is, doing it yourself will ensure the guy that doesn't know what he's doing, accidently did it correctly or not.