What Is Going On Here?

New England SteamWorks

First time visit to a home this morning. The issue is banging, sometimes horrendous. Of course, it wouldn't bang while I was there...

The first floor was converted to baseboard and runs off a hot water loop. 2nd & 3rd floors are still steam. The owners tend to feel the banging is sort of everywhere, but largely on the first floor (where there is no steam).

Let's look at the steam first. I drew a diagram so you can better understand what I found (ignore near-boiler piping, I just pasted in an old one I did). All the piping is original, still neatly wrapped in asbestos. It's in a high-end neighborhood so I rule out hackery back in the day. Starts out like counter-flow, but not. And mains only 2". Maybe enough now for counterflow with the 1st floor being hot water, -but definitely too small for counterflow for the whole house, which is large, and which is how it was I am sure for longer than the baseboard.

All supplies labeled A thru D have radiator takeoffs. My initial thought is to turn Supply B into a dry return and end the collision of steam. I also wonder if this isn't how it originally was and the guy who did this install converted it to a supply. The vents are drawn in the correct locations, but they are not Gortons, just some puny little things from 1/4" tappings. Beefing up the venting is obviously.



Here's the near-boiler piping:



Then there's the hot water loop: No air scoop, no PRV, no expansion tank, and no relief:



How does it even work? And could the banging really be from the hot water loop, given no expansion tank and no relief? Could be, huh? That would be a first: A banging steam system where the steam side isn't banging, but the hot water side is! Of course, both could be banging. I am scheduled to return very early Monday morning when they think the conditions will be ripe for the Big Bang.

STEVEusaPA

Did you close the ball valve to the circulator? I'd see if those zone valves are sticking, not opening.

Jamie Hall

I'm not sure I can see any good reason why it wouldn't bang... at least until the steam mains are all hot. Is this basically a one pipe system?

New England SteamWorks

@STEVEusaPA : Yes, we closed the ball valve to drain and flush the boiler. Open again now. The house does heat. Just very loudly!

@Jamie Hall: Yes, it's a one-piper.

Snowmelt

whats the purpose of the 2nd line running parallel with the pump, is that a return for steam? I'm thinking not because of where the aqua stat is?

Fred

It looks to me like steam will hit water running past the riser in Supply "A" as the water runs past that riser to the drip. Looks like supply "B" drips back into the header and also, Supply "D" will hold water as a result of that 2" being reduced to a 1.25 return, on the horizontal. Also seems like the vent on the drip for supply "A" would close almost immediately as steam will hit that vent at the start of a steam cycle. I also see riser for supply "A" is on a Bull Tee to that Supply and Supply "B" bulls into supply "C". Tapping for the riser out of the boiler is reduced, a lot.

lchmb

is the hydronic loop piped off the coil or the wet portion of the boiler? If the wet portion of the boiler why would it need an expansion tank, prv and air scoop?

Big Ed_4

It's an condensate heating loop , with no boiler bypass and an big **** circulator pushing in to zone valves . .. No Hartford Loops either .. ..

Gsmith

What is the capacity of the boiler compared to the risers and header and mains looks like a very large reduction right at the boiler top outlet. Might be slinging a ot of water up to those counterflow mains.

j a_2

It’s one of them you say, your not going to like what I tell you but honestly it’s a mess..

Ironman

I'm not a big fan of running the hot water loop above the water line of the boiler without a HX. Too many things to go wrong: water boiling at the top of the loop; air getting in and causing the column to collapse which in turn floods the boiler; etc.

When it's not piped right (like this one), the circ pushing water into the header.

It looks like the circ is pumping toward the boiler, which is wrong.

If it's pumping away, then you've got a dead pocket between the circ and the zone valves if there's a flow check in the circ. Never seen zone valves without a HX on a hot water loop. Again, problem may be there if there's a flow check in the line.

I'd say repipe it right and put a HX between the boiler and the hot water loop. Or, put a separate boiler for the hot water loop.

Just my 2 cents worth.

New England SteamWorks

Snowmelt said:

whats the purpose of the 2nd line running parallel with the pump, is that a return for steam? I'm thinking not because of where the aqua stat is?

It's a steam condensate return.

New England SteamWorks

Gary Smith said:

What is the capacity of the boiler compared to the risers and header and mains looks like a very large reduction right at the boiler top outlet. Might be slinging a ot of water up to those counterflow mains.

Have we decided this is counter-flow?! Seems like some weird hybrid....

New England SteamWorks

Ironman said:

I'm not a big fan of running the hot water loop above the water line of the boiler without a HX. Too many things to go wrong: water boiling at the top of the loop; air getting in and causing the column to collapse which in turn floods the boiler; etc.

When it's not piped right (like this one), the circ pushing water into the header.

It looks like the circ is pumping toward the boiler, which is wrong.

If it's pumping away, then you've got a dead pocket between the circ and the zone valves if there's a flow check in the circ. Never seen zone valves without a HX on a hot water loop. Again, problem may be there if there's a flow check in the line.

I'd say repipe it right and put a HX between the boiler and the hot water loop. Or, put a separate boiler for the hot water loop.

Just my 2 cents worth.

The circ is pumping away. There is no flow check. I found that out because there is no manual fill on the boiler except after the circ, and when opened it dutifully filled the boiler.

EBEBRATT-Ed

I think @Big Ed @Ironman are right . It's a hw loop with no hx so you don't need a prv, expansion tank or air scoop.

Somebody probably drained it at some point and got air up into the hw loop. Looks like a mess to me. Maybe it will work if filled and vented. But the hw "return" near the pump needs to be separated from the condensate return by putting it in a different tapping if available. Don't believe it can wor very well the way it is.

the sure fix is a hx for the hw loop as @Ironman suggested

New England SteamWorks

I've never piped a loop without a coil or heat exchanger. Never did because I went on too many calls where someone had and it was always trouble.

New England SteamWorks

EBEBRATT-Ed said:

I think @Big Ed @Ironman are right . It's a hw loop with no hx so you don't need a prv, expansion tank or air scoop.

Somebody probably drained it at some point and got air up into the hw loop. Looks like a mess to me. Maybe it will work if filled and vented. But the hw "return" near the pump needs to be separated from the condensate return by putting it in a different tapping if available. Don't believe it can wor very well the way it is.

the sure fix is a hx for the hw loop as @Ironman suggested

Here is the hot water return. It is separate from the condensate return:

Fred

New England SteamWorks said:

Gary Smith said:

What is the capacity of the boiler compared to the risers and header and mains looks like a very large reduction right at the boiler top outlet. Might be slinging a ot of water up to those counterflow mains.

Have we decided this is counter-flow?! Seems like some weird hybrid....

Supplies "A" and "B" look like Counter flow, "C" and "D" appear to be parallel.

Steamhead

How much steam radiation is on this system? Is is possible to determine how much steam radiation was on the first floor before it was hacked?

New England SteamWorks

Steamhead said:

How much steam radiation is on this system? Is is possible to determine how much steam radiation was on the first floor before it was hacked?

Educated guess: 350 was on the 1st floor before conversion

New England SteamWorks

Fred said:

Supplies "A" and "B" look like Counter flow, "C" and "D" appear to be parallel.

Exactly. A confusing hash.

Maybe Supply E should be cut and capped, leaving B as the only supply, and A & D the dry returns. Would make sense given current vent placement. Otherwise the drip on "A" seems too serve no purpose...

But, -it all looks original, as I say...

GW

I may have read too fast but here are some thoughts

Was the system ever working well in the opinion of the homeowner?

What decade did the hw conversation happen? You’re saying the “pre HW and all steam” was on the Smith? Just curious about what happened when. It’s a pain to peel back the layers

As previously mentioned, the near boiler piping looks small, one 2” is good for connected steam? Seems like a big house.

The hw loop, what’s the rule of thumb—up to 1/3 heating capacity?

Can the owners simply figure out a pattern? Sometimes I need to tell the people to pay attention to what zones are on and or off. It seems basic to us but maybe not them

You’re positive the boiler is in its original position? Original chimney? The counterdlow seems odd. Aren’t they needing to be dripped?

If there’s no Hx you don’t need a relief or so I thought

It’s not a zv slamming right? Seems like the Zone valves are backwards? I never would have expected to see zv on a condensate job. Maybe cycle the zv on and off

kcopp

I think the hot water zone is flashing to steam when it turns on. That would get a decent size bang....

New England SteamWorks

Current homeowners bought 5 years ago. Has always banged as now. Smith installed in 2011. Given that it was installed in January, I am guessing that the baseboard and loop either were already in, or added sometime after. But prior to current owners.

GW

I’ve seen (and done several) condensate B.B. jobs, they normally don’t flash. I’d be curious to know what would cause that. Assuming of course the boiler pressure isn’t jacked

GW

Ok just wondering. Does the B.B. look like it’s 7 years old?

New England SteamWorks

GW said:

It’s not a zv slamming right? Seems like the Zone valves are backwards? I never would have expected to see zv on a condensate job. Maybe cycle the zv on and off

Good catch. The circ is pumping away, so the ZVs are backwards. The owner did tell me he had to replace the circulator awhile back (not unusual). Could be whoever replaced the circ flipped it. They had just enough cable for the current configuration and not enough for the other without extra work...

EBEBRATT-Ed

Baseboard loop cannot exceed pick up capacity of the boiler or you may not have enough steam. Should be a bronze circ that's why they don't last.

So the pipe tied into the condensate return is the hW return? and pipe on front of the boiler is the supply?

New England SteamWorks

@EBEBRATT-Ed

Steamhead

New England SteamWorks said:

Steamhead said:

How much steam radiation is on this system? Is is possible to determine how much steam radiation was on the first floor before it was hacked?

Educated guess: 350 was on the 1st floor before conversion

350 total including the first floor? Or 350 just on the first floor? If the former, a single 2-inch main will handle it.

New England SteamWorks

@Steamhead, the 350 is my quesstimate of what the 1st floor steam EDR was, prior to removal and installation of baseboard. The 2nd and 3rd floor steam EDR is likely around 300-400.

2" can handle parallel flow, but counter-flow? And how did it handle it when it was all steam? 2" too small for counter flow.

GW

I see the strap on, maybe disallow the water loop from pumping when steam is calling to keep extra hot water from flowing , run the steam stat through the NC on then Honeywell

And, if it flashes doesn’t that automatically mean you lost your water loop?

Flipping the circ (or zone valves) seems like a basic first step. But you’re leaving a whole lot of question marks

I’m kinda curious from a business standpoint how you address this situation. Maybe another topic for another day. I get a little skittish when there’s all sorts of issues. I become more psychologist than mechanic with some of these things I run into. If you fix everything you just got paid a lot of money. If you make a teensy repair and leave the other stuff, you’re still in the loop (so to speak)

New England SteamWorks

GW said:

I see the strap on, maybe disallow the water loop from pumping when steam is calling to keep extra hot water from flowing , run the steam stat through the NC on then Honeywell



And, if it flashes doesn’t that automatically mean you lost your water loop?



Flipping the circ (or zone valves) seems like a basic first step. But you’re leaving a whole lot of question marks



I’m kinda curious from a business standpoint how you address this situation. Maybe another topic for another day. I get a little skittish when there’s all sorts of issues. I become more psychologist than mechanic with some of these things I run into. If you fix everything you just got paid a lot of money. If you make a teensy repair and leave the other stuff, you’re still in the loop (so to speak)

@GW , I feel exactly the same way. That's why I thought I better post it up here and get as much feed back as possible. To be honest, I have yet to formulate a plan in my mind. My inclination is to go big, or go home. But if a tiny fix is possible, it would be irresponsible not to pursue it..

GW

Ahh yes and in my humblest of opinions we don’t have much business etiquette here, which is cool. If I met the homeowners I’d have some hard opinions on this topic based on their personalities.

This is just me——so take it with a grain of salt.

Plan 1
HO is a little matter of fact, probably educated, expects you to know everything, says “you’re the pro”, says “are you sure this will fix it?”, “ I just want this don’t once”, ——-I could go on but you get my point. With these people I throw the book at it. No need for me to lose too much energy over someone else’s problems. Also, if the spouse isn’t talking much, make them talk, you need to try and understand if they’re a factor or not if things don’t go well (few things are worse than an angry spouse not talking until things go south) This is a red light, you throw everything you have at it. You’re almost looking for a No. If it’s a Yes, amen, just write down the variables you still have no control over (if there are any) and do your thing

Plan 2
HO is easy going, smiles, respects your time and understands we are pros and treat us as such. They say “whatever it takes”, the two spouses are both communicating and they seem in synch with each other, and they don’t trivialize our skill sets..... then that’s a green light. You can go step by step. You just spell out the steps and do Not forget to say, in your kindest manner possible, “ worse case is we need to do everything I have on this paper and that is (point to the bottom of the page) the most this could cost”

I hope this helps a little

Steamhead

New England SteamWorks said:

@Steamhead, the 350 is my quesstimate of what the 1st floor steam EDR was, prior to removal and installation of baseboard. The 2nd and 3rd floor steam EDR is likely around 300-400.

2" can handle parallel flow, but counter-flow? And how did it handle it when it was all steam? 2" too small for counter flow.

Supply B is the only part of that setup that looks like it was always counterflow. Supply A was probably parallel-flow originally until someone piped that branch into the boiler steam side.

If there are radiator takeoffs from Supply B, they probably don't generate enough condensate to cause an issue, as long as Supplies A, C and D are parallel-flow.

New England SteamWorks

@Steamhead: Well, -here's the thing: All of the piping is still wrapped in original asbestos. In order for Supply A to have originally been parallel-flow the pitch would have had to have been reversed, which would have meant altering all of the take-offs along the way. And I see no evidence of alterations anywhere. All original. All pitching up and away from the boiler.

But wait: You've given me an idea: What if Supply B was originally the only supply? I know there is at least one take-off there (but no where near as many as on the perimeters), but it might not be original, will have to look tomorrow. But just suppose Supply B was lowered. That it originally pitched down and away from the boiler. Then the system would make some sense (well, except for Supply E, which is obviously original...):

Steamhead

OK, I missed the supply E designation. But if Supply E wasn't there, then Supply A would feed from Supply B and would then be parallel-flow. That would explain the current pipe pitches. I bet Supply A heated slowly way back when and, not knowing about big main vents, they brought steam into the other end of Supply A via Supply E, and covered it all in asbestos.

Verify your radiation counts and get back to us.

GW

I’m no asbestos expert but I wonder if there could have been a re pipe sometime after the original install and then re insulated .

Either a goober piped the system on day one (it’s possible), or there was a re pipe 60 years ago, or it’s a big mystery it’s unusual to see counterflows without drips

GW

I’m no asbestos expert but I wonder if there could have been a re pipe sometime after the original install and then re insulated . You do more steam than I do, that’s just some odd piping it seems

Perhaps a goober piped the system on day one (it’s possible), or there was a re pipe 60 years ago, or it’s a big mystery it’s unusual to see counterflows without drips

How about the 2nd and 3rd fl risers? If there was a remodel maybe someone offset a pipe somewhere

Also, no expansion tanks on a condensate loop, and I’m not sure I’ve ever seen an air scoop on one either.

Fred

I know @New England SteamWorks says the piping all looks original but I do think it warrants a closer look. In my mind, if it was originally a parallel flow, the typical piping configuration, back in the day would have probably been a loop that might have included one riser out of the old coal boiler, Supply "A", "C" and "D" would have been the loop and the return at the end of supply "D" would have gone back to the boiler and dropped into a short wet return. I think Supply "B" and that short drip off of Supply "A" was added at some later point.
If it was originally a counter flow, the same loop would have been used, with supply "C" and "D" pitched back towards "A" and the original drip, in front of the main riser, was removed. JMHO

Big Ed_4

Those Taco's are slow operating units ...The strap on is there to maintain hot water for the baseboard on an call for heat with out producing steam ..... You would need an expansion tank , pressure relief valve and feed valve on an closed system .. Like on an heat exchanger ... Right now it's an open system .. Years ago we only see an condensation on basement heating , below the water line.. .. If you wanted to heat upwards floors you used an sidearm ... The newer boilers today are two short for gravity side arms , tube heat exchangers with two circulators will be my course to solve the problems .... Always instal an boiler bypass for the boiler circulator ..