Steam boiler scale

M Ransley

I have an old 50 yr Kewanee boiler on Chgo water , not real hard. How can you tell if you have scale, How much can it reduce efficiency, and how do you cean it. thanks all@ the wall.

Carl_5

Scale is flacky white looking stuff, and smells like sulfur when it gets hot. Brush it out to clean it but you might wanna talk to a heat professional he can probably do a better job and make sure its running right. Well if your worried about efficiency why is your boiler 50yrs old? First you should start with updating your heating system, let me ask you a question, not tryin to be a wise guy but what else do you own that you use everyday that is 50 yrs old?

M Ransley

I dont understand I thought Scale was inside the boiler, where you cant see or smell or get to it , since the boiler is sealed.
I would consider replacement but at 15000 and a 20 yr payback gaining only 15% eficiency it is not possible now. I beleive in modern equipment . Im putting in a 94% Ao Smith Cyclone 250a water heater , mine is leaking and payback is two years on a 94% vs 80%. And in my house I have Tankless gas Water heater , 94% furnace, etc. etc.etc

Carl_5

Scale is inside the boiler yes, but there has to be a way to open it up to brush it but its something you probably shouldnt be doing yourself. Did you get a quote for $15000 for a boiler install?

Tony Conner

Scale...

...will form on the water side of your boiler. It's caused by adding hard water. If your system has been maintained (steam and condensate leaks repaired relatively quickly), there shouldn't be much scale in the boiler. I don't know the specifics of your boiler, but there should be a way to look into the water side when it's shut off and cooled down. (This tends to be something that happens at the end of the heating season.) You should be able to see the metal. If there's a white-ish crust (exactly the same as you can see in a tea kettle), that's scale. It's bad because it acts like insulation on the heat transfer surfaces. You'll burn more fuel to get the same heat output. The thicker the scale, the greater the insulation effect. Normally, it requires chemical process to remove it. The first thing to do, is check that you actually HAVE a problem. I've seen lots of 50+ year old equipment that works just fine. Old isn't necessarily bad, if it's been maintained.

Be cautious about the "percent efficiency" values being tossed around by the manufacturers of various types of equipment. These are NOT necessarily "apples to apples" comparisions. And much of the time, people are ripping out old steam systems that are basically just fine based on some mis-information. I've seen lots of old steam systems where there has been a condensate tank with a failed pump - or even just the level switch - that has been letting nice hot, soft condenate run to the floor drain beside it for literally years. The steam boiler takes the blame for "poor efficiency", and high fuel bills. The usual "solution" is to rip out the steam system and replace it for tens of thousands of dollars. Sometimes, it's the right thing to do, because the steam system is too far gone, or has been butchered. At least as often, simple things (like condensate tank problems) can be fixed for a fraction of the boiler replacement cost, and make a nice drop in the fuel bill as a result. And nobody has actually touched the boiler itself.

M Ransley

Yes i had a 15000 quote for replacement. The new water heater cost me uninstaled, [that happens next week ] 4200 and retails for 5400apx.
I see a plate apx 16"x 8" above the tube door , its bolted on by alot of bolts. Is this the inspection plate ? Id be worried those bolts would break trying to remove them. Thanks all-wall

Tony Conner

Sounds Like...

...an opening into the fireside of the boiler. I'm not familiar with this make of boiler though, so maybe someone else can tell you how to get a look into the water side. There has to be plugs or oval handholes. Note that plugs that have not been removed for decades can be a "special treat" to get out.

scrook_2

fireside or waterside?

on the waterside ( think this is your question), I'd not worry especially if the water's soft and sure wouldn't touch it if it's 50 yrs old -- you create a few leaks and it's new boiler time, you leave it alone and you can replace it at leisure -- say summer, during plant shutdown, or other, as appropriate to the boiler's use.

I assume it's a steam boiler not hot water, the latter should see very little makeup water over the years, a steamer will see more makeup to quite a lot of make up depending if it just is used for heating or is being used for process steam -- in the latter case particularly you might look at water treatment programs upon replacement of it.

On the fireside (steel firetube boiler I assume?) brush out the tubes w/ an appropriate flue brush, but hopefully this has been being done annually or so as PM.

Here's a picture of a 50HP (~1,670,000 BTU/hr) 1926 Kewanee

http://www.jeromegrandhotel.net/hotelkewanee.htm

Tim_16

Older Boiler

There are handhole plates and maybe a manhole plate on the boiler. Pull them and look inside. And what I advise you to do this spring..And this is coming from a guy that has been a boilermaker for over 25 years. Call a boiler repair shop and have them look at your boiler..Not a residential repair shop..If the burner is in good shape..Retube the boiler and replace the bottom..And you will have a reliable boiler for another 50 years

Tim_16

I see you are in Chicago...There are plenty of boiler shops..Let me know which ones you want to call..I'll tell you if they are good shops to deal with

M Ransley

Tim - fireye, sure id be interestd in who you reccomend. I had the outside bottom replaced by Spannuth they are good. Im having Kirwin do a regular go over this week with a burner efficiency test. Id like to get this unit running as good as possible. thanks

Tim_16

These are the boiler shops I recommend..I don't care much for Spannuth boiler..They are non-union..I recommend Hayes Mechanical , Andee Boiler , Chicago Welding , Nolan Boiler , Or Midwesco Services. If you call one of them you just might get me looking at your boiler..Goodluck