TDS and level instability in a new boiler

nicatniter

We recently replaced the late 40's steam boiler in our 1929 2-storey home, just in time for heating season! It has run off and on (mostly off due to mild weather) for about a week. This is 2-pipe steam and the new boiler rates 299,000 btu/h input. We are in the Midwest, in an area where steam is a bit unusual in a single-family home. We used an experienced and reputable firm but they deal mostly with apartment buildings and such.

The installers cautioned me that the first year there would be a lot of instability due to "total dissolved solids", and gave seemingly conflicting advice on how to address it: either do complete boiler flush several times a season; or do a partial drain out of all 3 valves (wet return, blowdown, and low water cutoff) on a weekly basis. And indeed all 3 drains gave off a lot of inky sludge the one time I opened them.

I also notice the water level goes pretty crazy in the sight glass during firing, and a lot of sludge enters the glass from the top. They didn't mention skimming, but I'm pretty sure from other posts that this is a job that ought to be done right away for any new boiler (probably I will pay extra for it). It looks like the boiler is tapped at the water level just behind the backup low water cutoff (a very inconvenient spot, actually).

Question 1: What is the appropriate way to break in a new boiler w/r/t TDS?
Question 2: Is skimming advisable right away?
Question 2: Given the amount of sludge, should I consider having the wet returns cleaned? Is this something that should be prioritized for the health of the system, or could it wait till next year?

I'm attaching some pictures of the new system (and the old one just for fun).

Thanks,
Jon

Fred

Did they not boil the boiler out? That should have been done before the boiler was put into service. It will take many skims before you get all the oils out of it. Using the drains won't work. It just drains water and lets much of the oil cling to the sides of the boiler so that when you refill the boiler, the oils are still on the surface. Several slow skims will allow the oils to float off of the top of the water. your water in the sight glaff will be very unstable until you get all the oils out.

BobC

This thread has some good information on skimming. Did they install a skimming port on your boiler? The manual should show where the port is supposed to be.

http://forum.heatinghelp.com/discussion/148210/skimming-weil-mclain-eg-55-steam-boiler

Bob

JStar

They also need to install the second riser from the boiler to the header. That is a big enough boiler to require two risers. What model is it? If they add the second riser, make sure that it isn't welded. The near-boiler piping needs to be threaded and offset to allow for movement, without stressing the boiler sections.

Robert O'Connor_12

The 2nd low water cut off looks like it's right in front of (and in the way) of using the skim tapping.
Nice looking job!

nicatniter

Fred said:

Did they not boil the boiler out? That should have been done before the boiler was put into service.

No, that was not done! But I will be on the phone with them first thing tomorrow for sure!

nicatniter

BobC said:

Did they install a skimming port on your boiler? The manual should show where the port is supposed to be.
Bob

Thanks - a 2 1/2 inch 'Skim tapping' pipe is specified in the manual. I think it's shown (capped) in the attached photo.

nicatniter

JStar said:

They also need to install the second riser from the boiler to the header. That is a big enough boiler to require two risers. What model is it? If they add the second riser, make sure that it isn't welded. The near-boiler piping needs to be threaded and offset to allow for movement, without stressing the boiler sections.

This is a Weil-McLain EG-75 with 247 MBH. The manual specifies a single riser pipe with 3" diameter, 3" header and 1-1/2" equalizer for this model. (Dual risers starts with model EG-85 and up.) So I think according to the spec it is OK.... but as you look at the existing riser (in the un-insulated photo in my original post) do you see problems with its threading and offset? I wasn't sure exactly what you meant by 'not welded'.... but I think I get it: threading allows the possibility of torquing of the piping that welding doesn't. The manual specifies offset headers but doesn't go into detail about thread vs weld...

Hey many thanks to all who've responded so far, I certainly have some issues to address....

JStar

nicatniter said:

JStar said:

They also need to install the second riser from the boiler to the header. That is a big enough boiler to require two risers. What model is it? If they add the second riser, make sure that it isn't welded. The near-boiler piping needs to be threaded and offset to allow for movement, without stressing the boiler sections.

This is a Weil-McLain EG-75 with 247 MBH. The manual specifies a single riser pipe with 3" diameter, 3" header and 1-1/2" equalizer for this model. (Dual risers starts with model EG-85 and up.) So I think according to the spec it is OK.... but as you look at the existing riser (in the un-insulated photo in my original post) do you see problems with its threading and offset? I wasn't sure exactly what you meant by 'not welded'.... but I think I get it: threading allows the possibility of torquing of the piping that welding doesn't. The manual specifies offset headers but doesn't go into detail about thread vs weld...

Hey many thanks to all who've responded so far, I certainly have some issues to address....

Looks like you're right. The manual does state those sizes as the minimum. According to my charts, that boiler would require two 3" risers into a 4" header as a borderline minimum. Since you're having issues, it's worth bringing up as a solution if cleaning and skimming doesn't solve the problem.

Robert O'Connor_12

The 1 &1/2" capped skim tapping is your best bet. See (if possible) if it could be utilized.
May have to modify/move or remove (for skimming purposes only) in order to use it.

gerry gill

The skim tapping has to be made accessible and usable otherwise you will be hard pressed to ever get the water clean. I'm not picking on their install here, as they did nice 'clean' craftsman like work, i just wonder how many steam boilers they have done as they made servicing difficult. I also like the well done insulation. How does it heat? if i may ask.

gerry gill

Also, i'm glad the boiler return trap was left (in the background)..is it still functional? If not you will need a vaporstat. If its still in service, no worries.

nicholas bonham-carter

I can't see what the hoffman 75 vent is connected to. Can you take a better picture of that? It looks like a bottle, and is green on the end of a vertical pipe.
You must have a very big house to need such a large boiler. How did they choose the boiler?--NBC

Steamhead

Another thing- I would not have used that model low-water cutoff/water feeder. It has no way to track the amount of water the system takes in. Excessive feed water will drastically shorten the boiler's life.

The secondary LWCO on that boiler is a probe-type, which has no moving parts. On these EG/EGH boilers, one can use a remote probe in the tapping close to the sight glass (lower tapping J on page 38 of the manual) and mount the primary LWCO control box nearby where there's room. Then you can use a Hydrolevel VXT water feeder which has a built-in counter to track water usage.

The manual is here:

http://www.weil-mclain.com/en/assets/pdf/550-142-782_1112.pdf

nicatniter

gerry gill said:

Also, i'm glad the boiler return trap was left (in the background)..is it still functional? If not you will need a vaporstat. If its still in service, no worries.

We have no reason to think it wasn't working but I don't think it's been tested before or after the install. What would be the symptoms if it stopped working -- no steam getting to the radiators due to blocked returns?
Thanks
Jon

nicatniter

Steamhead said:

Another thing- I would not have used that model low-water cutoff/water feeder. It has no way to track the amount of water the system takes in. Excessive feed water will drastically shorten the boiler's life.

The secondary LWCO on that boiler is a probe-type, which has no moving parts. On these EG/EGH boilers, one can use a remote probe in the tapping close to the sight glass (lower tapping J on page 38 of the manual) and mount the primary LWCO control box nearby where there's room. Then you can use a Hydrolevel VXT water feeder which has a built-in counter to track water usage.

The manual is here:

http://www.weil-mclain.com/en/assets/pdf/550-142-782_1112.pdf

I'll discuss this with the installer....I assume I could also have a water meter installed upstream and keep track manually - as Holohan's book suggests (gee, I wish I'd read it through more carefully before the job got underway .)
Thanks,
Jon

nicatniter

nicholas bonham-carter said:

I can't see what the hoffman 75 vent is connected to. Can you take a better picture of that? It looks like a bottle, and is green on the end of a vertical pipe.
You must have a very big house to need such a large boiler. How did they choose the boiler?--NBC

Here is a photo that shows the return vent. It's actually mounted on a trap of some kind. It definitely is venting when the system makes steam, as I can hear it hissing.

Regarding boiler sizing, I sent them these measurements:
1st floor
7 in-wall convectors - 40 inch
1 in-wall convector - 30 inch
1 wall-projecting radiator 27" h x 16" w x 5" d with 5 sections (3 channels each), upper/lower pipes 24" apart on center

Landing
1 wall-projecting radiator 27" h x 24" w x 5" d with 10 manifolds (3 channels each), upper/lower pipes 24" apart on center

2nd floor
4 freestanding radiators 19"h x 32"w x 12"d with 13 sections (7 channels each), upper/lower pipes 15" apart on center
1 in-wall convector - 30 inch

I wasn't privy to any EDR estimates....

What can I do if the boiler's too big?

Thanks,
Jon

nicatniter

nicholas bonham-carter said:

I can't see what the hoffman 75 vent is connected to. Can you take a better picture of that? It looks like a bottle, and is green on the end of a vertical pipe.
You must have a very big house to need such a large boiler. How did they choose the boiler?--NBC

Sorry I forgot to attach the vent/trap photo! I also attach a photo of the other bigger trap (which has no vent) and a crude diagram of the return piping. There are 3 return lines and only #3 is connected to the vent (at right in diagram). I wonder how the other returns are vented? Maybe there used to be a vent on the big trap (red circle)?

Steam definitely reaches all the radiators in the house so I'm not sure if it's 'broken' but it would be nice to understand how it all works.

Thanks
Jon

nicatniter

gerry gill said:

The skim tapping has to be made accessible and usable otherwise you will be hard pressed to ever get the water clean. I'm not picking on their install here, as they did nice 'clean' craftsman like work, i just wonder how many steam boilers they have done as they made servicing difficult. I also like the well done insulation. How does it heat? if i may ask.

They specialize in steam boilers, have been around a long time and have a good reputation, but most of their clients are apartments or larger. Residential is unusual for them, but I reasoned that by hiring them I'd be getting better boiler expertise, and not many of the residential HVAC companies around here will even bid on a steam system....

The skim tapping is definitely accessible, but it's just capped off. The instructions say pipe it to the floor drain, skim for a couple hours, then remove the piping and plug it. I've been in touch with the installer, and it appears that although they heated and drained the boiler 3 times, they didn't skim, which means they didn't get the oil out.

As to the heating, it's a new system and fall has been mild, so hasn't been put to the 'real' test, but I can say steam reaches all the radiators within 15 minutes when I crank up the thermostat. It's just that I can see all this junk floating in the sightglass and the level bounces a good 3 inches or more during firing (my reading suggests that ~3/4 inch is 'normal' bounce).

Hopefully a good 'skim' will stabilize things!

Thanks,
Jon

KC_Jones

Just to give you an idea of how cruddy a brand new boiler can be. Here is a picture of my brand new never fired Weil Mclain (eg-40) and the crud I am washing out of it. I have not fired it yet nor skimmed I am using a wand to wash it first @gerry gill . In this pic is the first bucket of crap I got out of it. So far I have washed with about 25 gallons of water and it's still coming out brown. Once I fire it I will have to skim again once all the crud from the new piping is steam cleaned and dropped into the boiler. If you read enough on this site you will realize this boiler cleaning is not only important, it's very time consuming! Good luck and hope you get the water settled.

nicholas bonham-carter

there was a simple chart here showing the most common radiator types, and sizes, and their EDR in square feet, from which total, the boiler must be sized. Too big a boiler will short cycle its way to an early grave, enriching the gas company, and of course, too small won't heat.
I hope the installers "chose wisely"--NBC

Fred

You will most likely have to skim this boiler multiple times to get the water bounce to stablize. Don't be discouraged about that. Do a good slow skim, per the instructions in the manual or on this site, run the boiler for a few days, when you see the water bounce wildly again, do another skim. Just repeat that process until the water finally stabalizes. Be aware that each skim must be extremely slow, with a trickle of water out of the skim port, on larger than the diameter of a pencil (smaller is even better). Your goal to to allow the oils to rise to the surface of the water in the boiler so any turbulance is a bad thing as it will allow the oils to be dispursed throughout the water. Once the oil is on the surface, it will slowly stream out of the skim port. I had to skim my boiler four or five times before I finally got it stable and that was after just some pipe repairs. In your case, with a whole new boiler that wasn't cleaned and some pipe work, it may take even longer but in the end you will see the difference.

nicatniter

nicholas bonham-carter said:

there was a simple chart here showing the most common radiator types, and sizes, and their EDR in square feet, from which total, the boiler must be sized. Too big a boiler will short cycle its way to an early grave, enriching the gas company, and of course, too small won't heat.
I hope the installers "chose wisely"--NBC

Thanks, I hope so too. Maybe I'll ask them to show their work! Keep in mind this is the upper Midwest so the system needs to keep pace even when it's -18 F and -40 wind chill.

KC_Jones

"Thanks, I hope so too. Maybe I'll ask them to show their work! Keep in mind this is the upper Midwest so the system needs to keep pace even when it's -18 F and -40 wind chill."
The only thing that matters on steam systems is the size of the radiation. You size the boiler to the radiators since they basically have a fixed output, putting a bigger boiler than is required doesn't put out anymore heat just burns more fuel and as mentioned shortens boiler life. This topic is harped on a lot on this site because it is so important to size the boiler properly. If the contractor didn't measure every radiator in your house and calculate the total EDR of your system then size the boiler by that and only that...they may not have gotten it right. A lot of people on here recommend homeowners do their own measurements to make sure contractors are doing it right. I did and found my boiler was over sized and all the contractors wanted to continue that trend. I am just another homeowner, but take all the advice you can from people on here there are a lot of very intelligent people with great advice.

nicatniter

I agree 100%! This site is an absolutely awesome resource. I'll see what I can find out about "my" EDR.
Thanks,
Jon

Fred

I don't think anyone wants to add stress to you as it relates to this situation. Is the boiler sized properly? Who knows at this point. given the way they installed this boiler, I don't think they are "fly by night". They seem to have done a decent job. Sure everyone has a "prefered" way of installing but the big question is "Did they install it in a professional manner, and to at least, the minimum required by the manufacturer. I think they did. The only KNOWN issue at this point is that the boiler needs to be cleaned. Once that is done, let's see how it works and once you get past the known issue, you can take your time measuring your EDR and comparing that to the boiler size. You can even ask the installer to show you the calcs on how he determined the boiler size. I'm betting they are close enough that, if need be, the burner can be tweaked (down fired) a bit.

icesailor

" and it appears that although they heated and drained the boiler 3 times, they didn't skim, which means they didn't get the oil out. ""

Not a Steam Expert but, think of "skimming" a new steam boiler to cooking a big pot of stew with some meat like pork shoulder with a lot of fat. The fat/oil will rise to the top. Unless you want a fat stew, you need to skim the fat from the top of the stew. You can either use a special fat separating spoon and skim it, or you can put the stew in the fridge and let the fat congeal into a solid. Then, you can spoon off the congealed fat. Once you heat up the stew, you can't skim the fat anymore. All that oil and crud floats to the top of the boiler. You can't skim the fat from the stew by draining out the water on the bottom.

Any steam installer who doesn't understand the concept of skimming, never made a fat stew. Or didn't equate the stew with the boiler.

Paul48

Someone posted a video a while back, showing what a tiny amount of oil added to a boiler does to the steam. Anyone still have that? I think the OP, like most ,would be amazed.

KC_Jones

Paul48 said:

Someone posted a video a while back, showing what a tiny amount of oil added to a boiler does to the steam. Anyone still have that? I think the OP, like most ,would be amazed.

I came across this one a while ago. Not sure if this is what you are talking about, but this shows the surging that can be associated with a boiler that needs skimmed. The second is a link to a video of what the water level should look like when steaming. A little bouncing.
http://www.youtube.com/watch?v=eqpbPPmiEXg
http://www.youtube.com/watch?v=DYNzAYjd5K8

Paul48

The one I was thinking about was an open hose with steam blowing from a boiler.When a tiny amount of oil was added, it turned into more of a garden hose than steam.

KC_Jones

Don't think I have seen that one, hopefully someone remembers and can post it. That sounds interesting.

nicatniter

Thanks to all. As an update, the installers have agreed to add a skim pipe.
-Jon

nicatniter

KC_Jones said:

Paul48 said:

Someone posted a video a while back, showing what a tiny amount of oil added to a boiler does to the steam. Anyone still have that? I think the OP, like most ,would be amazed.

I came across this one a while ago. Not sure if this is what you are talking about, but this shows the surging that can be associated with a boiler that needs skimmed. The second is a link to a video of what the water level should look like when steaming. A little bouncing.
http://www.youtube.com/watch?v=eqpbPPmiEXg
http://www.youtube.com/watch?v=DYNzAYjd5K8

That's quite a difference! Mine looks more like the top video, unfortunately. The old adage "oil on troubled waters" definitely does not apply to steam

vaporvac

That's great. You might want to have them add a ball valve while they're at it. You'll be skimming MULTIPLE times and it makes it SO EASY to just open the lever rather than having to futz around with the plug. They may charge extra for that, but you could always buy it yourself and add it.

I do think the controls on not well placed, but if that doesn't pose a problem for you that's the main thing. I use a wand fashioned after Gerry Gill's (LOVE IT!!!), and it would be a tight fit to use it and a bucket. My boiler gave @4 ft. as the minimum distance to a wall for servicing.

nicatniter

nicatniter said:

KC_Jones said:

Paul48 said:

Someone posted a video a while back, showing what a tiny amount of oil added to a boiler does to the steam. Anyone still have that? I think the OP, like most ,would be amazed.

I came across this one a while ago. Not sure if this is what you are talking about, but this shows the surging that can be associated with a boiler that needs skimmed. The second is a link to a video of what the water level should look like when steaming. A little bouncing.
http://www.youtube.com/watch?v=eqpbPPmiEXg
http://www.youtube.com/watch?v=DYNzAYjd5K8

That's quite a difference! Mine looks more like the top video, unfortunately. The old adage "oil on troubled waters" definitely does not apply to steam

Does anyone have a handle on the physics behind this effect (that is the effect of oil on the stability of water that's generating steam?) The little I can find online focuses on the detrimental long-term effects of oil deposits on boiler steel, i.e. carbonization and localized overheating. (Sounds like another good reason to get rid of it!).
-Jon

nicatniter

vaporvac said:

That's great. You might want to have them add a ball valve while they're at it. You'll be skimming MULTIPLE times and it makes it SO EASY to just open the lever rather than having to futz around with the plug. They may charge extra for that, but you could always buy it yourself and add it.

I do think the controls on not well placed, but if that doesn't pose a problem for you that's the main thing. I use a wand fashioned after Gerry Gill's (LOVE IT!!!), and it would be a tight fit to use it and a bucket. My boiler gave @4 ft. as the minimum distance to a wall for servicing.

They want to extend the tube down to the floor drain "for safety reasons". I'm not concerned about a small amt of oil going down the drain, but is there any reason not to do this vs a bucket?
Thanks
Jon

nicholas bonham-carter

Yes!! You will emptying that bucket many times, so if you have a floor drain, to which the skim port can be piped to, then so much the better. Point out to them that they are learning things which they should know already, which will be a benefit in any future installations.
Point them to this site.--NBC

Steamhead

It's the Weil-McLain demonstration boiler that is piped in Pyrex glass. There are pictures around- I had some from a long time ago but can't find them now.

nicatniter

Update: I finally got a skim port installed. It's above water level so I use the backfill water valve to bring the level up to where it overflows into the port. After two skims over a couple days, the boiler is behaving beautifully. Attached is a photo showing what came off early on in the second skim.

Fred

Glad to hear things have worked out. Skimming is so important to the operation of a steam boiler.

vaporvac

Thanks for the update and glad to hear the happy ending.