Boiler Scale Removal

SLFinney

After having my 20+ year old Weil-McLain boiler serviced last year, the tech said that the "snap crackle and pop" noise it makes is probable due to scale buildup.

How can this be removed? Is this condition typical?

Thanks Scott

DanHolohan

Is this

steam or hot water?

SLFinney

Dan,

This is circulating hot water boiler, 177,000BTU input / 144,000 BTU output. It has a single Grundfos circulator (replaced @5 years ago) pump, and two zones controlled by Honeywell 8043 zone valves. The boiler uses a Aquatrol(?) expansion tank with integrated fill valve.

This house has experienced severly corrosive water from a city well system and a salt-based water softener system. As a result, ALL of the copper DVW pipes have been replaced. Our community has since switched to munincip[al water, and the water softener has been removed. The copper piping for the hot water heat appears to be solid, however.

I have attempted to get some expert help locally (Northwest Suburban Chicago), but most shops around here start by suggesting I replace the boiler with forced air. I am going to installa Spirovent Jr. on this unit, as I have to bleed this boiler a few times each year - any thoughts on where the air is coming from would also be appreciated.

Thanks again, Scott

PS - I enjoyed your book Hydronic Radiant Heating - is there a companion volume on Boilers and baseboards?

hr

Depends on

what kind of a sludge you have. Typically in a new installation a soap based cleaner works best to cut grease, oil, flux, etc. itis best to try and determine what the build up is.

If your system has a small leak and has been taking on fresh water for years, you may have a hard water (calicum) build up. For this you will need an acid based cleaner like the Sizzle product. Most of the plumbing chemical companies have these types of cleaners. Use acid cleaners with extreme care and flush the system thourghly after cleaning.

Try Able Dist. in Chicago, they are hydronic friendly 773- 889-5555 ask for Mike or Jeff at the Evanston branch 847-869-6500.

Don't forget to check for leaks with a good, accurate, pressure gauge.

20 years is a good life cycle for that boiler. Time and money may best be spent on a new unit. Heat transfer efficiency goes way down when the surfaces get a mineral build up. Sometimes an acid bath will develop pin holes in thin areas under the scale build up.

Able sells Weil also Good luck

hot rod

To Learn More About This Contractor, Click Here to Visit Their Ad in "Find A Contractor"

SLFinney

Thanks for pointing me to a local source. I was a little embarrassed to admit that one of the reply's I got from another board was to use TANG (as in the space station) as a way to remove scale. I suppose that citric acid would actually work.

This boiler does seem to run all the time, and our gas bills are sky-high

Thanks again, Scott

Glenn Harrison

I noticed you said you got Dan's book "Hydronic Radiant Heating". Is it safe to assume you have some radiant heat on this system. If so you probably have a leak in the radiant tubing which has caused you to need to add new water to the system thru the years. This will cause you to slowly get air in the system, and more importantly new minerals from the water which accumulate in the boiler. If this is the case you need to find and repair the leak. You can put in the Spirovent, but it may be just puting a bandaid on a much bigger problem. This would also explain the air bleeding and the snap, krackle and pop. You can acid flush the boiler to get rid of the minerals and the noise, but be prepaired for the fact that the boiler may start to leak especially being that it is 20 years old and is a Weil-Mclain with elastomeric seals. Those minerals may be holding that boiler together. I'm a service tech for a contractor out of Crystal Lake so I know how aggressive and how high the lime and mineral content of the water is in the Northwest suburbs. If you would like, feel free to contact us and we can give you a full evaluation of the system, and we WILL NOT tell you to convert to scorched air! We LOVE boilers.

Glenn Harrison

Althoff Industries Inc.
Crystal Lake, Illinois
800-225-2443
www.althoffind.com

P.S. Got to the "PIPE" on the top left and click on "Books and more". There you can see a list of ALL of Dan's books, order the ones you want, amd learn EVERYTHING you wanted to know about you hydronic system. And if your wondering, the answer is YES I have all of Dan's books and they are terrific. Thanks Dan.

Bob E

Scale build-up

I see this quite often. If it's not too bad you can use TSP found in the paint store as a cleaner. Tri-sodium phosphate.
Make a strong solution and add to the boiler water. Let it go for a few weeks drain and repeat if nessecary. The poppoing noise in my experience has usually come from lime build-up on the heat transfer surfaces. This acts as insullation and the boiler runs all the time, doesn't heat well and has a high stack temperature. Remember if you are a homeowner that the boiler is under pressure, you have to shut off the water to the system and drain enough water to take the pressure off. Water will still spew if you don't have valves to the heating system. Usually this is best done by a contractor but it's not beyond a handy DIY guy. Good luck!