Boiler possibly oversized?

SKR918

Hi there!

Newbie here, and I made the unfortunate mistake of finding this helpful site *after* purchase and installation of a new steam boiler. I ordered one of Dan's books, and it will arrive tomorrow.

We had a 90,000 BTU boiler, and it was replaced with a 112,000 BTU system. The sales person said this would be no problem, that in fact we would have better heat. This was before I learned about measuring the EDR. I did that last night, and came up with a BTU measurement of 91,000.

Well, we've had nothing but issues: boiler overfilling, severe water hammer, water spurting out of air vents, and the sound of water boiling coming from the radiator.

They keep coming back to fix all of these individual issues, but - is it possible that the boiler is simply too big for our house? The techs are saying no, but something just doesn't seem right to me.

Thanks very much in advance for any advice you can give.

pecmsg

Oversized and piping issues is my WAG!

Can you post pictures?

Dave0176

Post pics of your piping around the boiler, and what was the EDR number not BTU?

ChrisJ

Yes, please post pictures of the boiler and it's piping.
Post pictures of a few radiators as well.

SKR918

Wow, thanks for the speedy replies. I will do that as soon as I am home from work this evening!

vaporvac

SKR918 said:

Hi there!
Well, we've had nothing but issues: boiler overfilling, severe water hammer, water spurting out of air vents, and the sound of water boiling coming from the radiator.
Thanks very much in advance for any advice you can give.

Your boiler may very well be over-sized, but many of the issues you're describing result from improper piping, and dirty, oily water. Have they skimmed the boiler properly, ie. not just putting an additive in or draining from the bottom, but skimming from the skim port just above the water line? This generally takes hours and needs to be done a few time, at least.

Robert O'Connor_12

Sounds dirty

SKR918

I've attached some photos of the boiler. It is a Carrier BS2 Series B.

Please forgive if I'm using wrong terminology. Here's how I arrived at my measurement:
I measured the height of all of the radiators, counted the tubes and used the advice on this page: http://www.comfort-calc.net/Sizing_A_Steam_Boiler.cfm. I came up with 254 square feet of steam (EDR?). Another page advised me to take that number, multiply by 1.5 pick-up factor, and then multiply by 240 to get me at 91,440 BTU.

I will say that the company has been quite responsive, but nothing seems to help for more than a few hours. They have skimmed it (although not for hours, maybe 1/2 hour tops), drained it, cleaned the pig tail, cleaned the water sensor. The first piping job wasn't right, the pictures below are how it is now. (let me know if I need to take better pictures).

The radiator pictured below is at the end of the line, it's the one that was spurting. That has stopped, but when I got home tonight, I found that the sight glass was once again full of water.

I'm trying to learn as much as I can, so thanks very much for your help.

Fred

Look on the boiler spec plate and see what the rated Sq. Ft. of steam output is. That should closely match your 254 sq. ft of EDR. Obviously this boiler is over-sized but I think you need to skim it yourself. I see a skim port on the side of the boiler. Skimming it very slowly for 2 or 3 hours will help a lot. It may take several skims to get all the oils off the surface of the boiler water. Make sure the Pressuretrol is set for a Cut-in of .5 PSI (scale on the front of unit and take the cover off of the Pressuretrol and make sure the white wheel inside is set to "1" for a Cut-out of 1.5 PSI.
Tell us if you can determine the location of the water hammer and send us a picture of that area. It is very possible the installers did something to change the pitch of a pipe causing water to pool in that area. When steam hit a pool of water, it will hammer.

Dave0176

The near boiler piping is minimal they followed somewhat the manual, however they did not pipe in a skim port. This is to be installed were the that first Elbow out of the boiler turns up, it should've been a Tee. So you definitly need a good cleaning and skimming.

Also those Vairvalves are terrible, (experience) you cannot balance the system with them for nothing.

Also did they install any main vents??

BobC

Steam boilers are rated in BTU's and sq ft of steam. If you have 254 EDR then you need a boiler rated for about that number, the sq ft rating includes a 33% pickup factor that is more than enough for most systems.

That looks like a Dunkirk style of boiler so it's sensitive to piping and water quality. Some Dunkirk style boilers really want to have both side output taps used for stable operation. Maybe somebody else knows if this is one of those boilers.

Does the water in the sight glass bounce up and down a lot when it's making steam? If it does the boiler needs more skimming and it may take several skimmings to get the water clean..

If the water isn't bouncing up and down the autofeeder may be leaking by, try turning the water feed off so the auto feeder can't let water into the boiler. Do this when your home so you can keep an eye on the boiler.

Bob

Fred

@Dave0176 Skim port is on the left side of boiler.

Dave0176

Fred said:

@Dave0176 Skim port is on the left side of boiler.

Yep didn't see that in the pic.

Dave0176

It's not crazy oversized but would benefit from a two stage gas valve.

SKR918

Fred said:

Look on the boiler spec plate and see what the rated Sq. Ft. of steam output is. That should closely match your 254 sq. ft of EDR. Obviously this boiler is over-sized but I think you need to skim it yourself. I see a skim port on the side of the boiler. Skimming it very slowly for 2 or 3 hours will help a lot. It may take several skims to get all the oils off the surface of the boiler water. Make sure the Pressuretrol is set for a Cut-in of .5 PSI (scale on the front of unit and take the cover off of the Pressuretrol and make sure the white wheel inside is set to "1" for a Cut-out of 1.5 PSI.
Tell us if you can determine the location of the water hammer and send us a picture of that area. It is very possible the installers did something to change the pitch of a pipe causing water to pool in that area. When steam hit a pool of water, it will hammer.

The booklet says Net AHRI Rating Sq. Ft = 283. Is that what you mean?
The Pressuretrol is set at .5.

The hammer seems to be coming from under the floors, and echoing into the radiators.

SKR918

Dave0176 said:

Also those Vairvalves are terrible, (experience) you cannot balance the system with them for nothing.

I don't like this valve either. It's making this awful breathing sound, like there is some kind of weirdo in the room with me. Will go out and get a new one this weekend.

Fred

Yes, the 283 is what you compare the Radiator EDR against. As Dave0176 said, it is over sized but that is not what is causing your issues. The boiler needs more skimming. If you have banging under the floor, (if on first floor) look at that area of piping, in the basement, and make sure the Main has some pitch to the returns and that the radiator run-out pipe is pitched back to the Main. If the hammer is under a second floor, try to raise both ends of the radiator a 1/4" or so and then repitch the radiator towards the return pipe if this is a 2 pipe system, back towards the supply pipe if a 1 pipe system. Raising the radiator a bit will hopefully change the pitch of any horizontal pipe enough to let condensate flow.
Also, the .5 on the Pressuretrol is correct for Cut-in. Make sure the white wheel inside is correct as well . Set at "1" facing the front of the Pressuretrol.

SKR918

Dave0176 said:

Also did they install any main vents??

Yes...if I am looking at the correct thing. But, it has no identifying marks.

BobC

If it's making a breathing sound you may find a pipe that is dead level or slightly pitched the wrong way. Go over the piping with a level and make sure it's all pitched correctly.

Replace the varivents with something slower, I'd suggest trying the maid o mist kits that come with 5 different orifices.

http://www.amazon.com/Maid-Steam-Angle-Radiator-Valve/dp/B003DV3AGE/ref=sr_1_1?ie=UTF8&qid=1455845447&sr=8-1&keywords=maid+o+mist

Also what kind of main vent is on the system and how long is the steam main?

Bob

Abracadabra

Was the boiler properly skimmed. If yes, how?

SKR918

Fred said:

Yes, the 283 is what you compare the Radiator EDR against. As Dave0176 said, it is over sized but that is not what is causing your issues. The boiler needs more skimming. If you have banging under the floor, (if on first floor) look at that area of piping, in the basement, and make sure the Main has some pitch to the returns and that the radiator run-out pipe is pitched back to the Main. If the hammer is under a second floor, try to raise both ends of the radiator a 1/4" or so and then repitch the radiator towards the return pipe if this is a 2 pipe system, back towards the supply pipe if a 1 pipe system. Raising the radiator a bit will hopefully change the pitch of any horizontal pipe enough to let condensate flow.
Also, the .5 on the Pressuretrol is correct for Cut-in. Make sure the white wheel inside is correct as well . Set at "1" facing the front of the Pressuretrol.

I will try skimming it myself this weekend. Maybe they didn't do it long enough. Would dirty water cause the sight glass to be overfilled?

One of the techs checked the piping and returns, and everything is pitched fine (and, we never had hammer like this before, only after the new boiler).
Just checked the white wheel, and it is set to "1".

BobC

If the boiler water is unsteady (needs to be skimmed) it may be dipping below the low water cutoff and turning on the auto water feeder which will result in an overfilled boiler.

If the water is not unsteady than the auto water feeder might be leaking.

Bob

Fred

Oil on the surface of the water will cause the boiler to push water back into the returns. That causes the Low water Cut-off to shut the boiler down and the auto water feeder to add more water to the boiler. At the end of the heating cycle, when all of the water returns to the boiler, it is over filled. That will be resolved when all the oils on the surface of the water is removed. As I said earlier, it may take several very slow skims to get all the oils out.
I'm still suspect that one of the radiator run-outs may be level or pitched the wrong way, causing the hammer.

SKR918

Thanks to all of you for your explanations and suggestions; I will be working on it this weekend. My dad was always my go-to-guy, but since he passed it's been like a ship without a captain. My husband is a great guy, but not mechanically inclined. Thanks for the advice, you guys rock!

SKR918

BobC said:

If it's making a breathing sound you may find a pipe that is dead level or slightly pitched the wrong way. Go over the piping with a level and make sure it's all pitched correctly.

Replace the varivents with something slower, I'd suggest trying the maid o mist kits that come with 5 different orifices.

http://www.amazon.com/Maid-Steam-Angle-Radiator-Valve/dp/B003DV3AGE/ref=sr_1_1?ie=UTF8&qid=1455845447&sr=8-1&keywords=maid+o+mist

Also what kind of main vent is on the system and how long is the steam main?

Bob

Thanks, Bob, I'll look into getting those vents instead. I may have to get a pro to look at the piping, some of it is in the crawl space and I've got claustrophobia!

vaporvac

Dave0176 said:

The near boiler piping is minimal they followed somewhat the manual, however they did not pipe in a skim port. This is to be installed were the that first Elbow out of the boiler turns up, it should've been a Tee. So you definitly need a good cleaning and skimming.

Also those Vairvalves are terrible, (experience) you cannot balance the system with them for nothing.

Also did they install any main vents??

Since they didn't install a skim port, I don't see how they skimmed. Draining from the bottom is NOT skimming as the oils still remain stuck to the sides of the boil and float on top as the water fills. It needs to be skimmed and they need to put in a skim port so you can do this yourself over the coming weeks and even months.

Fred

Repost here if you have other questions. You will get this resolved, for sure. Skimming is just slow. The best way to do it is to shut the auto water feed off, manually open the water supply valve that bypasses the water feeder and open the skim port. let water start to trickle out of the skim port (it may take a couple minutes). Turn the manual water valve down till just a trickle comes out of the skim port. If you can, hook a garden hose up to it and run it over to a floor drain and just let it trickle for several hours. You don't have to stay around to watch it that way. If you use buckets, you will have to stay close by to empty/change buckets. BE SURE YOU HAVE TURNED THE POWER OFF TO THE BOILER WHILE THE SKIM IS HAPPENING.

SKR918

vaporvac said:

Dave0176 said:

The near boiler piping is minimal they followed somewhat the manual, however they did not pipe in a skim port. This is to be installed were the that first Elbow out of the boiler turns up, it should've been a Tee. So you definitly need a good cleaning and skimming.

Also those Vairvalves are terrible, (experience) you cannot balance the system with them for nothing.

Also did they install any main vents??

Since they didn't install a skim port, I don't see how they skimmed. Draining from the bottom is NOT skimming as the oils still remain stuck to the sides of the boil and float on top as the water fills. It needs to be skimmed and they need to put in a skim port so you can do this yourself over the coming weeks and even months.

There is a skim port there, I think it's just not visible in the picture. I think they skimmed once or twice, but it was a real quick thing.

SKR918

Fred said:

Repost here if you have other questions. You will get this resolved, for sure. Skimming is just slow. The best way to do it is to shut the auto water feed off, manually open the water supply valve that bypasses the water feeder and open the skim port. let water start to trickle out of the skim port (it may take a couple minutes). Turn the manual water valve down till just a trickle comes out of the skim port. If you can, hook a garden hose up to it and run it over to a floor drain and just let it trickle for several hours. You don't have to stay around to watch it that way. If you use buckets, you will have to stay close by to empty/change buckets. BE SURE YOU HAVE TURNED THE POWER OFF TO THE BOILER WHILE THE SKIM IS HAPPENING.

I will make sure to do that!

SKR918

SKR918 said:

Fred said:

If you can, hook a garden hose up to it and run it over to a floor drain and just let it trickle for several hours.

OK, last question for today...the skim port has a 1.5" fitting, much larger than a garden hose. Is it ok to attach a reducer, so that I can connect a hose?

Fred

Yes, That will work.

KC_Jones

I'm with Hat on this one. I personally don't like the hose because you can't monitor what is going on it's all hidden inside the hose. With Hat's idea it speeds things up (wish I had that when I skimmed mine). But even so without either idea you skim so slowly that it will take hours to fill a 5 gallon bucket so it's not like you have to stand there staring at it the whole time. And then there is the issue of reducing the connection size and not being as effective due to reduce surface area.

SKR918

Hatterasguy said:

SKR918 said:

OK, last question for today...the skim port has a 1.5" fitting, much larger than a garden hose. Is it ok to attach a reducer, so that I can connect a hose?

What you really want, and what I currently use, is a cap that fits over the end of the 1.5" fitting with 1/4" high slot cut across the entire face of the cap between the threads.

Did you make this cap yourself, or is it something that I might find in a hardware store or plumbing supply?

SKR918

Rats.

Hatterasguy...yesterday you mentioned that it was a bit oversized. I understand that the current symptoms are likely caused by dirty water in the boiler.
But, is it a bad thing to be slightly oversized, or is this something that might be OK?

ChrisJ

Hatterasguy said:

That must be made yourself.

Although, I am considering making a batch of them for the board. This business of skimming for "hours" by the uninformed has to stop.

Yeah,
It's called a Gerry Gill wand.

Skimming is for the birds.

To the OP, this is what I would do. When I did it on my boiler I put the wand in the skimmer and used the boiler drain into a bucket to catch the dirty water. My wand was connected to my water heater drain so I was washing with good hot water.

https://youtu.be/q1tw9rz-pUk

SKR918

ChrisJ said:

Hatterasguy said:

To the OP, this is what I would do. When I did it on my boiler I put the wand in the skimmer and used the boiler drain into a bucket to catch the dirty water. My wand was connected to my water heater drain so I was washing with good hot water.

https://youtu.be/q1tw9rz-pUk

That absolutely looks like it would do the trick. But, that's way beyond my skill set, I'm just a homeowner who's only slightly handy...

SKR918

Hatterasguy said:

SKR918 said:

Rats.

Hatterasguy...yesterday you mentioned that it was a bit oversized. I understand that the current symptoms are likely caused by dirty water in the boiler.
But, is it a bad thing to be slightly oversized, or is this something that might be OK?

It might be fine.

An oversized boiler will tend to build pressure with time. If you run the boiler for 10 minutes, it won't build but an ounce or two of pressure. If you run it for 30 minutes, it might build 1.5-2.0 lb.

If it builds pressure sufficiently to shut itself down on pressure (usually at about 1.5-2.0 lb), that is undesirable as it just restarts itself two minutes later and repeats this inefficient process.

You will know if this occurs when you stand in front of it after a 20 minute (or more) run and the pressure climbs to the point where it shuts down and restarts quickly thereafter.

If this occurs, it should be addressed as it is inefficient and hard on the equipment.

But, it may never occur if the 'stat satisfies and shuts the boiler down before the pressure climbs above 1.5 psi.

Thanks for the explanation. I think it may be doing this, but it's hard to tell because it's been cold. I will keep observing it.
Thank you!

SKR918

I will definitely look into that. TY

Fred

@SKR918 , the reducer and hose will work. I have a Burnham boiler that I have to skim using the 3/4" port that the Pressure relief valve is mounted on because there is not a traditional skim port (although I wish there were). As I said set the trickle before you put the hose on. There is only so much surface area in a boiler. It's not a lake.
EDIT: Looking at the way Hattersguy does it will certainly work faster but some of us have to use what we have with our older boilers. I know Hat has a particular Brand of boiler that is problematic when it comes to needing skimming. Necessity is the mother of invention.

ChrisJ

Hatterasguy said:

ChrisJ said:

Yeah,
It's called a Gerry Gill wand.

Skimming is for the birds.

Wash to your heart's content.

It will not eliminate the need for skimming as you already know.

Disagree with you there,
The hot water will wash the oil off and out of the boiler. I'd follow it with a slow skim just to be sure, 99% of the oil will come out with the wand.

ChrisJ

Hatterasguy said:

I've yet to see water remove oil from anything.

They make mineral spirits for that.

Come over in a month, I'll show you a pressure washer remove oil from concrete with ice cold water.