Steam Boiler Make-up Water

heatman

I've seen lots of information about "too much" make-up water causing pre-mature steam boiler corrosion from the oxygen in the water. Can anyone tell me what is "too much"? I know water usage will vary with boiler size and climate (and leaks of course), but certainly a given boiler can tolerate a certain amount of water replacement cycles per season, regardless of size and weather. Any guidelines here?



I have a 13 gallon boiler that has to add about 2-3 gallons per week in the winter. Is that okay? I don't see any leaks anywhere and the vents are working fine.



Similarly, I see lots of information about "too much" chloride in the make-up water causing excessive corrosion. What is "too much"? My water supply comes from municipal wells that have about 140 ppm of chloride and 50 ppm of sodium. Is that okay?



I'm asking because I'm about to buy my 4th steam boiler in 17 years. Very expensive.

JStar

Steam

You'd figure by the second boiler that somebody would stop and wonder why they were failing so often. For me, 1 to 3 gallons is max usage during a whole season, if you never drained the boiler.



Has the piping been changed with every new boiler? Is the piping correct?

Jamie Hall

Your municpal water quality

is fine.  Not to worry about that.



Your water consumption -- in my humble opinion -- is not.  Your mileage may vary, of course, as they say, but to give you a notion of "reasonable" water use, the building I supervise uses a moderately sized Weil-McClain (see my signature line).  Exclusive of the water lost blowing down the float type low water cut off (about half a gallon a month) it has used exactly 6 gallons -- in the last four years.  Of which 4 were in the first month since the new boiler was installed as it was settling in.



So.  Half a gallon a year to losses, plus about half a gallon a month -- say a pint a week -- to blowdowns.



Again, in my humble opinion, your water usage is contributing to the relatively early failure of your boiler.  The water has to be going somewhere...



By the way, your usage is, I believe, also over even what the boiler manufacturers themselves regard as "normal" -- figures which I think are excessive.

heatman

Steam Boiler Make-up Water

Thanks for the responses.



In response to the question about the piping. It has not been changed in terms of layout. The piping right around the boiler was replaced, but the design stayed the same. The installers thought that it was correct. I am not an expert, but the header is about 24" over the water line and the Hartford loop looks correct. Would any of this affect water usage?



In response to the comments about my water usage being high, any ideas on how to find out why? It certainly isn't obvious in the form of a leak.

JStar

Boiler

Any pictures of the boiler and piping? Is this a one or two pipe system?

heatman

steam Boiler Make-up Water

Here's some photos. It's a little hard to get a good shot since the boiler is in a small space.



First photo (leftside) shows top of boiler and header looking across the boiler from the left side. Second photo (rightside) shows the right side of the header at the top and the Hartford loop at the bottom. There is a drip line from the right side of the header down to the Hartford loop that is not visible since it goes behind the steel column and wall to the right.

Third photo (backside) shows the rear of the unit near the floor where you can see the wet returns to the left and the Hartford loop to the right.



The top of the Hartford loop is even with the boiler water line, not below as is recommended.

heatman

Steam Boiler Make-up Water

Sorry, forgot to mention that it is a one-pipe system, circa 1910.

JStar

Boiler

Have tou installed the same Burnham boiler every time? The piping looks okay. Not great, but better than an arrangement that would be damaging.

nicholas bonham-carter

Too many boilers

Is the boiler known to be leaking now? Have you overfilled the boiler above the top and seen some dripping into the firebox? Are any of the valves, or vents leaking due to excessive pressure?

It is possible that there is not enough swing in those swing joints, and maybe the resulting stresses have pulled the sections apart. In addition, the risers should come up about 2 feet above the waterline, and I can't see if that is the case. A drop header would accomplish this, used with a bigger header.

Have all the boilers been the same make, and replaced under some warranty?--NBC

heatman

Steam Boiler Make-up Water

Yes, the boiler has been replaced with the same model number every time. It made the piping easier. I was told that the warranty only covered the cost of the heat exchanger and the installer's price for ripping out the heat exchanger and replacing it was only slightly less than the price to buy and install a completely new knocked down boiler, so I chose the new boiler every time. Essentially, a useless warranty.



The bottom of the header is about 24" above the water line. It appears in perfect shape. No signs of any stress or leaking and I have never heard any hissing from it during operation. I have not confirmed that the current boiler is leaking but the make-up water went up drastically the other day (2 gallons per day).



From what others are telling me, the system is using too much water. It was using about 2-3 gallons a week during really cold weather. I replaced all vents and all radiator unions when the last boiler went in 9 yrs ago. (14 radiators total) All appear tight. I guess a pin hole in the system can ruin these boilers? Seems a little too delicate. Do I need to have a pressure test done on the system to find the tiny leaks? They certainly aren't visible.

Jamie Hall

Pressure test

Don't do it.  Steam systems -- and all their valves and unions and joints and what have you -- are designed to run on ounces of pressure.  Not pounds.  The odds of creating a leak where there wasn't one before are pretty good, and you don't really want to do that.



Further, you really can't test with air -- even slight changes in temperature make testing for leaks with air on an extended system impossible.



However, I have heard that adding a bit of oil of peppermint to the boiler may help, as it will evaporate along with the steam and, if you have a steam leak, you may smell it.  I've never tried it myself -- never had to -- but I've heard that it works.



Whatever, somewhere you have a leak, or leaks, and it will pay you to find them, even though it may take some time and patience.

JStar

Boiler

Unfortunately, Burnham has a reputation of leaking often and early. That being said, there is usually still a cause for it.

nicholas bonham-carter

Short-lived boilers

Are there any products containing chlorine, or sodium stored near the boiler?

Probably even a water softener could be a source of vapors which can be inhaled by the burner, and burned into the metal with disastrous results.--NBC

JUGHNE

Buried wet returns??

I see wet returns mentioned but are they buried or not visible?  As Dan says they are always suspected and usually guilty.