Problem with short-cycling, low water, and leaks

DiegoB

Hi all !

First, just to say - I absolutely love this community. I've been coming here to read all the good advice for years but this is my first post. I have both of Dan's books on steaming heating - absolute GOLD!

But, I couldn't find my answer in his books, so here goes ...

I have a house that is about 4500 sq/ft, high ceilings, and has 3 floors of living space. The insulation is quite good and windows are in relatively good condition.

In the winter of 2022, a plumber that I did enjoy working with, replaced a steam boiler that had a crack and was leaking quite a bit of water. This was in the middle of winter.

The previous boiler was a Weil-McLain, 6 Section SG0-6, and he recommended that we replace it with a Utica SBO-4150, which is a 4 section. I really didn't think it was the right machine, but he insisted that they are making boilers smaller these days and this should work well. It was kinda an emergency situation, so I went with it.

The change boiler change resulted in a drop of AHRI ratings from 180000 Btu/hr to 135000 Btu/hr, but I think the biggest difference was the reduction in the size of water reservior.

At the time, my plumber did not do a proper EDR calculation - measuring all the radiators and summing up the parameters. I did this myself after the boiler was installed. There are 27 radiators in the house and the total square footage (not accounting for pipes) is 782 sq-ft. all the pipes in the basement are uninsulated, so this may be around 950 sq-ft with the pipes. The EDR rating for the Utica is 563 Sq/ft - which is way under.

With the Utica, I'm getting short cycling like nobody's business b/c the water cutoff is always turning on. Before the radiators heat up significantly, all the water in the reservoir has been evaporated. At steady state, the radiators are getting up to around 140 degrees max - but not enough to close the air vents. So, I'm losing a ton of water to evaporation. My autofill has a digital meter and over the past four months, it's already let in more than 99 gallons of water. The meter only goes up to 99 gallons, so I'm sure it's way passed that now.

I've asked my plumber to replace the boiler with something more appropriate, but he's dragging his feet big time.

A couple questions for the group:
1) Can all that new water cause damage to my pipes and radiators?
2) How much should I pay and my plumber pay to get the boiler replaced?
3) What boiler what you recommend? I have oil now, but thinking of converting to gas.

Appreciate your help! Thanks in advance. Diego.

pecmsg

Please post pictures of the near boiler piping from a distance. 

pedmec

First things first. You need to find out why its short-cycling. And that can be a myriad of reasons. i recommend that you post pictures of the boiler so we can determine if the near piping is proper. If it's not it should be corrected. That could be the issue with short cycling. you're never going to heat the house if the boiler short cycles and the house is as big as it sounds.

Now i'm not defending the contractor. He should have measure all the radiators. But who's to say that the radiators ain't over-sized due to insulating and the new windows. you reduced the heat loss and that might help you (or the contractor). did he skim the boiler? insulate as much pipe as possible. just a start

ethicalpaul

There is a lot to unpack in your description, including some possibly incorrect thinking.

Your boiler may be undersized, but it's not as bad as you think or describe. The sq ft rating on your boiler already includes 30% oversizing for the pipes (which is plenty more than enough), so don't count the pipes in your calculation.

The fact that your boiler is shutting off on low water is almost certainly due to "surging" which means your boiler water is oily or dirty. It probably needs to be skimmed.

You talk about losing a lot of water to evaporation, but that doesn't make sense to me. Is your water level actually dropping significantly over time? We know it drops when your boiler is boiling, but again, that's due to surging, and all that water returns to your boiler. Edit: I read your post again, and you seem to actually be adding water to your system, a lot of water. You have a steam or water leak.

Have him skim it, and if he doesn't know what that is, tell him to learn or find someone else. Then once your boiler isn't shutting off all the time we can see how well it actually is heating your house.

My guess is that the size is going to be fine. You said in your post that you were losing water to evaporation (steam I assume you mean), but this does not sound right. Any steam that condenses will return to your boiler as water.

How long does it take after boiling starts for your low water cutoff to trigger?

Jamie Hall

Well that's different. Usually the problem we see is that the boiler is way too big...

There are those who will contend that even a boiler that significantly undersize can be made to work. I am not among them. Even if you were to insulate all the piping -- which you can't do unless all the risers are exposed as well as the basement -- you are sufficiently far undersized that it just won't be satisfactory. Balancing will be almost impossible, to start with.

In your plumber's defence, at least a little, the assumption these days with heating systems is that you can get away with a smaller boiler since people will have put in storm windows and better insulation. And this is true for hot water heat or scorched air. It is NOT true for steam.

So step one -- you are going to need a bigger boiler, correctly sized to the radiation.

That, however, is unlikely to be a cause of short cycling, even when it appears to be caused by dropping water levels. Yes, the water will drop when the boiler fires. It should not -- even in big systems with slow returns, drop more than a couple of inches. That it is dropping enough strongly suggests that there is something seriously amiss with the near boiler piping. That is using so much water, and not overfilling (that would be slow returns) makes me wonder if there is something else amiss going on. That amount of water loss without evidence of very high humidity in your living spaces suggests that there may be a leak somewhere.

LRCCBJ

The SBO-4150 has a net output of 180,000 BTUH. Your total EDR is 782 which results in a demand of 187,680 BTUH to fully fill all of them. This is without a piping or pickup factor. So, you have a negative pickup factor of 4%.

Once you cure the problem of the boiler cycling on pressure and insulate all the pipes you can see in the basement, this boiler will work perfectly fine. It is highly unlikely you NEED 180,000 BTUH if you were calculate the heatloss of the building.

The key to this success is to have proper near boiler piping, proper main venting, proper skimming of the new boiler (takes multiple weeks of effort (by you) to get it right), and proper insulation on the basement piping.

This boiler will perform fine.

SeanBeans

That water should be coming back. Where is it going? You have a leak somewhere 100%

Like Paul said above. You need to skim the boiler.

we also need photos of the new boiler and all it's piping from a distance 

also, are your steam mains vented?

DiegoB

Love the discussion, thank you all for responding.

pecmsg, pedmec - i'm posting a picture here. The near boiler piping is very consistent with the install manual from the manufacturer when I checked. I actually think the contractor did a good job on the install. It's just the boiler choice was not the best. what do you think?



The radiators have been in the house for a looong time, so some of them might be too large for the space. We could downsize some radiators, but I feel like we'd have to replace a significant # to make a dent. There is some exposed pipe in the basement that we could expose, but a lot of it insulated in the basement, so I don't think that would make a huge difference.

--

ethicalpaul - i know what you mean about the surging. i had that thought too and I did skim the boiler myself during the summer and it hasn't made a significant difference on reducing the new water that has to be put in. It did reduce some surging behavior though. The boiler may not have been skimmed during the install, possibly some left over residue.

I've checked the whole house multiple times for moisture around the floors and walls. If it was a focused leak, 99 gallons of water would be hard to miss. But because I don't see anything, I *think* the steam is leaving through the air vents on the radiators. It's happening at every vent throughout the house, so it is a very diffuse process. I've put thermometers directly on the rads and they are averaging around 125 degrees, and do not get past 135 degrees. I believe my air vents close at around 175-180 degrees. My previous boiler did not have this issue.

But, I'd love to hear any suggestions for other things to attempt ... if I can save the boiler, that would be great. The plumber suggested instead of putting in a new boiler, he'd give me a good price on installing a combi heating system on the first floor. Basically, take out all the radiators on the first floor and then put in baseboard heat ... essentially creating a zoned heating system for the first floor, and have the 2nd and 3rd floor run off the steam boiler. I'm inclined not to do this because steam is the better system in my opinion, i would take steam radiators over baseboard any day. Not sure if you have any thoughts on this?

--

jamiehall -- we tried some balancing, changing out main vents and playing around with vent sizes at the radiators. we do get better heat distribution, but the radiators just don't get hot enough and it takes a long time to satisfy the thermostat - i'm measuring 90-120 min on average.

Regarding the low water cutoff, could it be that we moved from a 6 section boiler to a 4 section boiler? There is just less water in the reservoir to start with, and the returns are slow?

We do not get huge changes in humidity, but we do get some - like 2-4% changes that are coincident with the boiler firing. We have 25 radiators in the house, so the steam is getting distributed over a lot of time and space. I'm not sure we'd really notice it from a humidity perspective unless we were measuring right at the vent.

Would love any additional thoughts you have.

DiegoB

ethicalpaul said:

There is a lot to unpack in your description, including some possibly incorrect thinking.

How long does it take after boiling starts for your low water cutoff to trigger?

Regarding this question -- it takes about 15-20 min for the low water cutoff to come on. I think it's programmed to wait 3-4 min before trying to start up again, by that time enough water has returned to allow it to start up again. Then it will run for another 15-20 min before hitting the low-water cutoff again.

mattmia2

Is this 1 or 2 pipe? Looks like 1 pipe from your pictures. Look in the manual and compare the sizing of the near boiler piping and the number of risers out of the boiler to the manual.

The water is almost certainly leaving the boiler as liquid water either through surging or priming throwing it in to the mains or being pushed in to the return or leaking.

I'll say it again, the water is leaving the boiler as liquid not steam, you need to figure out how and why.

Is it overfilled after the cycle ends? there could be buried returns in the basement floor that are leaking where you can't se it. could also not actually be filling when the auto feeder calls for water.

Does it bang? that is an issue other than boiler size.

when you account for the pickup factor baked in to the ratings plate edr you're not undersized enough to cause a problem if you are undersized at all. the edr calculations aren't prefect, 10% under in the math is within the error of the calculations.

don't rip out he 1st floor radiators, it isn't your problem and it will make it much less comfortable.

Steamhead

Is there a CycleGuard low-water cutoff on that boiler?

BobC

That picture shows two returns tied together above the boiler waterline. Returns have to be tied together BELOW the water line. The old boiler was much larger and probably had a higher waterline.
Drop that line down so it's well under the waterline and them do a few skimming's to get rid of any water contamination and see if that calms things down.

Bob

DiegoB

mattmia2 said:

Is this 1 or 2 pipe? Looks like 1 pipe from your pictures. Look in the manual and compare the sizing of the near boiler piping and the number of risers out of the boiler to the manual.

The water is almost certainly leaving the boiler as liquid water either through surging or priming throwing it in to the mains or being pushed in to the return or leaking.

I'll say it again, the water is leaving the boiler as liquid not steam, you need to figure out how and why.

Is it overfilled after the cycle ends? there could be buried returns in the basement floor that are leaking where you can't se it. could also not actually be filling when the auto feeder calls for water.

Does it bang? that is an issue other than boiler size.

when you account for the pickup factor baked in to the ratings plate edr you're not undersized enough to cause a problem if you are undersized at all. the edr calculations aren't prefect, 10% under in the math is within the error of the calculations.

don't rip out he 1st floor radiators, it isn't your problem and it will make it much less comfortable.

@mattmia2 - this could be true about the water leaving not as steam, but as water. Whatever is happening, we're losing a lot of water content very quickly. When we had issues with the radiators not getting hot, the plumber did upgrade the nozzle. Not sure if that could be heating up the water too quickly?

The water feeder is a VXT-120, and we have it set to stop filling at the low water cutoff. So it has feedback and feeds to a specific position everytime. It also has options to feed 1, 2, 3, 4, or 5 gallons at a time too, but this led to highly variable results when we set it to 2 or 3 gallons on each fill.

There are buried returns in the basement, and it's possible that there is some leakage there ... would we have to open up the concrete to investigate?

The system doesn't bang at all. I would say that the steam moving through the house is quite subtle.

DiegoB

Steamhead said:

Is there a CycleGuard low-water cutoff on that boiler?

Yes, here's a photo from the front:

DiegoB

BobC said:

That picture shows two returns tied together above the boiler waterline. Returns have to be tied together BELOW the water line. The old boiler was much larger and probably had a higher waterline.
Drop that line down so it's well under the waterline and them do a few skimming's to get rid of any water contamination and see if that calms things down.

Bob

@BobC - this is a really interesting point -- can you say how much lower it needs to be?

DiegoB

mattmia2 said:

Is this 1 or 2 pipe? Looks like 1 pipe from your pictures. Look in the manual and compare the sizing of the near boiler piping and the number of risers out of the boiler to the manual.

@mattmia2 - this is certainly a 1 pipe. The boiler does not have optionality for 2 pipes.

LRCCBJ

mattmia2 said:

The water is almost certainly leaving the boiler as liquid water either through surging or priming throwing it in to the mains.............

I'll say it again, the water is leaving the boiler as liquid not steam, you need to figure out how and why.

This is correct.

Although the boiler is piped per the installation manual with 2" permitted as the riser and header, the steam velocity becomes 45 ft/sec

This boiler should have a minimum of a 2.5" riser (ideally two risers) and preferably a 4" header to slow the steam and allow the water to drop out of suspension.

Notice there is absolutely no time for the water to drop in the very short distance between the top of the riser and the takeoff for the main.

Also, notice that the mains appear to be considerably larger than the riser.

Water is headed up to the radiators in considerable amounts.

dabrakeman

If you were to monitor the boiler water level for a significant period of time without running the boiler would you see any drop in the water level in the sight glass? If there is a major leak in the below water line returns then it should occur even if the boiler is off. If you don't see a drop then I would look elsewhere for a loss of water (vents, valves, etc...) before breaking up any concrete.

DiegoB

LRCCBJ said:

The SBO-4150 has a net output of 180,000 BTUH. Your total EDR is 782 which results in a demand of 187,680 BTUH to fully fill all of them. This is without a piping or pickup factor. So, you have a negative pickup factor of 4%.

Once you cure the problem of the boiler cycling on pressure and insulate all the pipes you can see in the basement, this boiler will work perfectly fine. It is highly unlikely you NEED 180,000 BTUH if you were calculate the heatloss of the building.

The key to this success is to have proper near boiler piping, proper main venting, proper skimming of the new boiler (takes multiple weeks of effort (by you) to get it right), and proper insulation on the basement piping.

This boiler will perform fine.

@LRCCBJ
ok, I'll continue to skim and see how that goes, and I need to double check to see if the returns are tied together at right place per @BobC 's comment. All the steam piping in the basement is exposed, so I could insulate that. We haven't tried it yet.

In regards to the BTU calculation, on the Utica spec sheet has three numbers
Heating Capacity = 180 MBH
Net Steam = 135 MBH
Net Steam EDR = 563 SQ-FT

For what the house needs, if we start from the calculated EDR from the radiators, I get the following numbers
Heat Capacity = 250 MBH
Net Steam = 187 MBH
Net Steam EDR = 782 SQ-FT (25 rads summed up)

Based on these calculations, we would want a heating capacity of 250 MBH and only getting 180 MBH?

@LRCCBJ -- What am I doing wrong?

ethicalpaul

Follow the steam through the main with your hand...you will know when the steam gets there. See where it's going. It is going somewhere, there is no way that none of your radiators are seeing steam--your boiler just isn't very undersized.

And it's not undersized AT ALL until all the radiators are getting filled up with steam. In a normal call for heat, you should see steam filling the main, then starting to fill each radiator (assuming your venting is OK).

When your call for heat starts, the steam is only going to go where the vents allow it to. The boiler has no idea that more radiation is hooked up than it can fill until all that radiation is actually getting filled.

Don't worry about pulling radiators. Something else major is going on, get a new steam contractor. If you live in North Jersey I'll come have a look for free.

https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/

DiegoB

Here are more photos of the boiler:

LRCCBJ

You are using the value provided by the manufacturer for "net steam". They put a 30% piping and pickup factor into this value so it is considerably smaller than the boiler output. That boiler has an output of 180 MBH. This equates to 750 EDR.

Of course, it would be preferable to have a bit more so that you have a 10% piping and pickup factor but there are plenty of installations that can manage close to zero if the piping is perfect.

That's why you need to change the piping at the boiler to slow the steam. You can probably get by with the 2" riser and enter a 4" header. The takeoff to the main needs to be at least 15" from the elbow where the riser meets the header. You have the capability to do this as the steam main is a considerable distance away from the riser (toward the camera).

DiegoB

LRCCBJ said:

mattmia2 said:

The water is almost certainly leaving the boiler as liquid water either through surging or priming throwing it in to the mains.............

I'll say it again, the water is leaving the boiler as liquid not steam, you need to figure out how and why.

This is correct.

Although the boiler is piped per the installation manual with 2" permitted as the riser and header, the steam velocity becomes 45 ft/sec

This boiler should have a minimum of a 2.5" riser (ideally two risers) and preferably a 4" header to slow the steam and allow the water to drop out of suspension.

Notice there is absolutely no time for the water to drop in the very short distance between the top of the riser and the takeoff for the main.

Also, notice that the mains appear to be considerably larger than the riser.

Water is headed up to the radiators in considerable amounts.

I know the piping is small. Everything you say makes sense, but here is the recommended piping in the install manual:

BobC

The sight glass sows the water level, any return piping should tie into each other and the boiler several inches below the bottom fitting of that sight glass.

Bob

DiegoB

BobC said:

The sight glass sows the water level, any return piping should tie into each other and the boiler several inches below the bottom fitting of that sight glass.

Bob

Thanks, we will definitely have another look at this!

DiegoB

LRCCBJ said:

You are using the value provided by the manufacturer for "net steam". They put a 30% piping and pickup factor into this value so it is considerably smaller than the boiler output. That boiler has an output of 180 MBH. This equates to 750 EDR.

Of course, it would be preferable to have a bit more so that you have a 10% piping and pickup factor but there are plenty of installations that can manage close to zero if the piping is perfect.

That's why you need to change the piping at the boiler to slow the steam. You can probably get by with the 2" riser and enter a 4" header. The takeoff to the main needs to be at least 15" from the elbow where the riser meets the header. You have the capability to do this as the steam main is a considerable distance away from the riser (toward the camera).

Thanks, we will definitely have another look at this. Crazy that the instructions call for a 2" header!

LRCCBJ

DiegoB said:

I know the piping is small. Everything you say makes sense, but here is the recommended piping in the install manual:

Yes, unfortunately, in the race to the bottom, ECR has recommended piping sizes that are simply too small to result in dry steam. This boiler would ideally be piped with TWO risers and they don't even offer that option!

Notice that they recommend the identical pipe sizes for the entire line, the smallest being 119 KBTU input and the largest being 210 KBTU input. This cannot possibly be correct.

The goal is to have a steam velocity of 15 ft/sec in the header with 15" between the top of the riser and the first takeoff for the main. This provides the best possible situation for dry steam. You have 45 ft/sec in the header with the main takeoff within 6" of the top of the riser.........nearly worthless to allow the water to drop from suspension.

DiegoB

ethicalpaul said:

Follow the steam through the main with your hand...you will know when the steam gets there. See where it's going. It is going somewhere, there is no way that none of your radiators are seeing steam--your boiler just isn't very undersized.

And it's not undersized AT ALL until all the radiators are getting filled up with steam. In a normal call for heat, you should see steam filling the main, then starting to fill each radiator (assuming your venting is OK).

When your call for heat starts, the steam is only going to go where the vents allow it to. The boiler has no idea that more radiation is hooked up than it can fill until all that radiation is actually getting filled.

Don't worry about pulling radiators. Something else major is going on, get a new steam contractor. If you live in North Jersey I'll come have a look for free.

https://heatinghelp.com/find-a-contractor/detail/new-jersey-steam-help/

@ethicalpaul - this plumber isn't a big steam guy. He was a plumber I have a good relationship with, and did his best on the job. I'm in the northeast, so a quite a ways from New Jersey -- huge thanks for the offer though!!!!

DiegoB

LRCCBJ said:

DiegoB said:

I know the piping is small. Everything you say makes sense, but here is the recommended piping in the install manual:

Yes, unfortunately, in the race to the bottom, ECR has recommended piping sizes that are simply too small to result in dry steam. This boiler would ideally be piped with TWO risers and they don't even offer that option!

The goal is to have a steam velocity of 15 ft/sec in the header with 15" between the top of the riser and the first takeoff for the main. This provides the best possible situation for dry steam. You have 45 ft/sec in the header with the main takeoff within 6" of the top of the riser.........nearly worthless to allow the water to drop from suspension.

Yes, absolutely agree - the steam coming into the main is going to be very very wet. It almost seems like one thing we could try is to reduce the nozzle size to get less aggressive heating? Would that work?

ethicalpaul

DiegoB said:

mattmia2 said:

Is this 1 or 2 pipe? Looks like 1 pipe from your pictures. Look in the manual and compare the sizing of the near boiler piping and the number of risers out of the boiler to the manual.

@mattmia2 - this is certainly a 1 pipe. The boiler does not have optionality for 2 pipes.

He doesn't mean the one supply pipe in the boiler, he means the number of pipes going to each radiator.

LRCCBJ

DiegoB said:

@ethicalpaul - this plumber isn't a big steam guy. He was a plumber I have a good relationship with, and did his best on the job.

If you try to discuss 4" with him, he'll have a heart attack because he cannot thread it. BUT, he can purchase all the 4" nipples that he needs and the 4"/1.5" reducing elbow for the equalizer and the Tee for the main without the need to thread anything on site.

The real question is what size is the Tee in the main?

ethicalpaul

I'd be sure it is surging before going down the road of re-plumbing. You should see the water level in the gauge glass drop dramatically if it is surging.

There is enough strange information in this thread that I'm not sure of anything right now.

KC_Jones

Knowing what I know today, I would take every effort to get that boiler tuned into your system. I recently changed my system so it is firing at a similar rate to the radiation as yours about -3% pick up factor, and the system is the best it's ever been.

I completely disagree with those saying change it, waste of money and time from where I'm sitting. The issues you are having have nothing to do with sizing, nothing at all. Losing water is a leak. To give perspective 99 gallons should be 10-15 years of water usage, and you say you have underground returns? That is the place to start with water usage. If they need replaced, I would not put them underground again unless there are zero other options, for me it's always been a dumb idea.

For reference to lose that much water through venting only, a Gorton #2 main vent would have to be venting steam continuously for ~340 hours to release 99 gallons of water. You wouldn't have to look around to find that, the walls dripping would tell the story. Also, since you say the steam isn't reaching the radiator vents, they can't be losing steam by definition.

After you make sure it's not surging and you aren't losing water, then you can tackle venting and balance. Start with main venting, then move to radiator venting, if necessary.

I agree with above about looking at upgrading that header and possibly separating the mains, it looks like they are tee'd together and while it's controversial around here, I believe it's better to have them fed off the header individually for balance reasons.

ChrisJ

At this point I agree, I'd work on getting the rest of the system fixed before touching the boiler, aside from skimming.

I'd also consider some good insulation on all of the piping.


That boiler is very far from a lost cause. It may work better than a larger one if things are done correctly.

DiegoB

KC_Jones said:

Knowing what I know today, I would take every effort to get that boiler tuned into your system. I recently changed my system so it is firing at a similar rate to the radiation as yours about -3% pick up factor, and the system is the best it's ever been.

I completely disagree with those saying change it, waste of money and time from where I'm sitting. The issues you are having have nothing to do with sizing, nothing at all. Losing water is a leak. To give perspective 99 gallons should be 10-15 years of water usage, and you say you have underground returns? That is the place to start with water usage. If they need replaced, I would not put them underground again unless there are zero other options, for me it's always been a dumb idea.

For reference to lose that much water through venting only, a Gorton #2 main vent would have to be venting steam continuously for ~340 hours to release 99 gallons of water. You wouldn't have to look around to find that, the walls dripping would tell the story. Also, since you say the steam isn't reaching the radiator vents, they can't be losing steam by definition.

After you make sure it's not surging and you aren't losing water, then you can tackle venting and balance. Start with main venting, then move to radiator venting, if necessary.

I agree with above about looking at upgrading that header and possibly separating the mains, it looks like they are tee'd together and while it's controversial around here, I believe it's better to have them fed off the header individually for balance reasons.

@KC_Jones - it's an odd theory, I know. I just haven't been able to identify a leak otherwise. Steam is getting to the radiators. I mean the house is getting steam heat now and we're in subzero temps, so steam is getting to the radiators. It's just that this boiler it hitting the low-water cutoff all the time.

If we take your Gorton #2 analogy and apply it to all the radiator vents. It would go something like this -- the entire house has the equivalent of about 5 Gorton #2 vents (assumption). 340 hours / 5 = 68 hours of venting. 68 hours of venting / 120 days = 0.56 hours per day. So, if there isn't enough steam being created to close the vents it's conceivable that over time steam is getting out that way. The easier thing to imagine is a leak in the return somewhere -- admittedly that is a possibility b/c we have not inspected that returns.

WMno57

DiegoB said:

Crazy that the instructions call for a 2" header!

https://uticaboilers.com/wp-content/uploads/2022/02/240013301-SBO-IOM-REV-B.pdf

2" is the minimum for the header. 3" would have been better. 2 1/2 and over requires a different pipe threader. Your plumber might not have the right tools, so he went with the minimum.
The main problem is the water leak.
There are contractors on the find a contractor tool who could fix your leak and repipe if necessary. Your plumber has flunked his internship by not doing an EDR survey, and suggesting the goofball idea of hot water heat for the first floor. Get someone else. Ask them if they can thread 3 inch pipe first.
https://heatinghelp.com/find-a-contractor/

ethicalpaul

At night fill up the boiler so that the water level is a little high (like almost at the top of the glass). Turn down your thermostat to prevent the boiler from firing all night. Mark the water level.

In the morning when the cold wakes you up, go look at the glass. If it's lower then you have a leak in the returns.

And there's no way all of your vents are leaking. And even if they all were leaking, they aren't going to leak any steam until their radiator is completely full of steam. Until that point they would just leak air, which is what they are supposed to do.

And with your undersized (or correctly-sized some of might say) boiler, it's not going to be pushing tons of high-pressure steam out of the vents anyway...it might not even matter if all of your radiator vents leak...because the steam won't really be getting there since it will be condensing in the radiators (which is really how a well-sized system should operate anyway).

DiegoB

OK - HUGE THANKS TO EVERYONE

1) Skim the boiler several more times
2) check the returns for leaks (fill up the reservoir kinda high and wait to see if the water level drops)
3) Insulate basement pipes
4) increase the header size to 3" or possibly 4" - aiming for 15 ft/sec
5) lower the position of where the returns tie in

Am I missing anything?

KC_Jones

DiegoB said:

KC_Jones said:

Knowing what I know today, I would take every effort to get that boiler tuned into your system. I recently changed my system so it is firing at a similar rate to the radiation as yours about -3% pick up factor, and the system is the best it's ever been.

I completely disagree with those saying change it, waste of money and time from where I'm sitting. The issues you are having have nothing to do with sizing, nothing at all. Losing water is a leak. To give perspective 99 gallons should be 10-15 years of water usage, and you say you have underground returns? That is the place to start with water usage. If they need replaced, I would not put them underground again unless there are zero other options, for me it's always been a dumb idea.

For reference to lose that much water through venting only, a Gorton #2 main vent would have to be venting steam continuously for ~340 hours to release 99 gallons of water. You wouldn't have to look around to find that, the walls dripping would tell the story. Also, since you say the steam isn't reaching the radiator vents, they can't be losing steam by definition.

After you make sure it's not surging and you aren't losing water, then you can tackle venting and balance. Start with main venting, then move to radiator venting, if necessary.

I agree with above about looking at upgrading that header and possibly separating the mains, it looks like they are tee'd together and while it's controversial around here, I believe it's better to have them fed off the header individually for balance reasons.

@KC_Jones - it's an odd theory, I know. I just haven't been able to identify a leak otherwise. Steam is getting to the radiators. I mean the house is getting steam heat now and we're in subzero temps, so steam is getting to the radiators. It's just that this boiler it hitting the low-water cutoff all the time.

If we take your Gorton #2 analogy and apply it to all the radiator vents. It would go something like this -- the entire house has the equivalent of about 5 Gorton #2 vents (assumption). 340 hours / 5 = 68 hours of venting. 68 hours of venting / 120 days = 0.56 hours per day. So, if there isn't enough steam being created to close the vents it's conceivable that over time steam is getting out that way. The easier thing to imagine is a leak in the return somewhere -- admittedly that is a possibility b/c we have not inspected that returns.

Your assessment is missing one thing. If the steam isn't closing the vent it's because it physically isn't there, so it doesn't matter that it's open, there is no steam to leak out. And again, that amount of steam leaking in your house you would know, easily as you'd have liquid water condensing on nearby cold surfaces, like the walls, or windows.

DiegoB

WMno57 said:

DiegoB said:

Crazy that the instructions call for a 2" header!

https://uticaboilers.com/wp-content/uploads/2022/02/240013301-SBO-IOM-REV-B.pdf

2" is the minimum for the header. 3" would have been better. 2 1/2 and over requires a different pipe threader. Your plumber might not have the right tools, so he went with the minimum.
The main problem is the water leak.
There are contractors on the find a contractor tool who could fix your leak and repipe if necessary. Your plumber has flunked his internship by not doing an EDR survey, and suggesting the goofball idea of hot water heat for the first floor. Get someone else. Ask them if they can thread 3 inch pipe first.
https://heatinghelp.com/find-a-contractor/

@WMno57 - The plumber threaded almost every pipe by hand. The install took 2 days! I think they were just going by the instructions. I had a look at the contractor list. I recognize some of the names from trucks driving around the area! Will give them a call to see if they can have a look.

DiegoB

ethicalpaul said:

At night fill up the boiler so that the water level is a little high (like almost at the top of the glass). Turn down your thermostat to prevent the boiler from firing all night. Mark the water level.

In the morning when the cold wakes you up, go look at the glass. If it's lower then you have a leak in the returns.

And there's no way all of your vents are leaking. And even if they all were leaking, they aren't going to leak any steam until their radiator is completely full of steam. Until that point they would just leak air, which is what they are supposed to do.

And with your undersized (or correctly-sized some of might say) boiler, it's not going to be pushing tons of high-pressure steam out of the vents anyway...it might not even matter if all of your radiator vents leak...because the steam won't really be getting there since it will be condensing in the radiators (which is really how a well-sized system should operate anyway).

I will definitely try this. In the summer, the water level stayed in the middle of the site glass but that is prob too low to test for leaks.