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john_117 Member Posts: 15
I have a Weil Mclean Ultra that has a lot of corrosion taking place inside the combustion side, any fix for this?


  • dpj
    dpj Member Posts: 2
    Water Test

    Your water chemistry is mosly out of wack!  Check the Ultra Manuals for specific guidelines.  Isolate your boiler, flush from the relief valve thru the boiler drain.  Apply pressure if possible.  You may most likely need to treat the system with Sentinel X400 Cleaner..."works great"!  Follow the mfr. instructions.  Once the cleaner has worked in the system, "you should operate the boiler for about 48 hours" flush the boiler and the system again.  Add Sentinel Inhibitor X100 as directed into the system. This should resolve your issue.
  • john_117
    john_117 Member Posts: 15

  • kcopp
    kcopp Member Posts: 3,820
    do you have....

    any pictures of your system? Who told you it is corroding? What are the specifics of your system... radiation, operating temperature, venting materials....
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    I have a Weil Mclean Ultra that has a lot of corrosion taking place inside the combustion side

    I am not a heating pro, but I do have a W-M Ultra 3.

    It just had its its third service Tuesday, and there was no corrosion on the fire side of the heat exchanger. Could your air supply and vent be set up so you were sniffing exhaust into the air intake? Is the air intake located near a source of harmful chemicals (listed in the installation manual)?

    I suppose you could remove the heat exchanger (looks like an awful job; maybe you could do it in place), soak it in warm water, and scrub it out with a bristly (not metal) brush to remove the corrosion. But if it has enough corrosion taking place this year, did not stuff turn up in the condensate trap in prior years?

    Could your heating contractor get the W-M technical rep in there to look at it. You probably do not want to buy a new heat exchanger, so you better figure this out very soon.
  • Matt_67
    Matt_67 Member Posts: 197

    Is it natural gas or propane?  Was a combustion test done on startup?
  • ColoradoDave
    ColoradoDave Member Posts: 54

    I guess the OP got his answers...

    BUT I found 2 cents and am going to give them here....


    -define corrosion? .... I've seen Ultra's after 4 years that 3 inches of silt in the bottom and had a solidified silt in the condescent drain tube... after a good cleaning and drain tube replacement, they work fine.  The silt is just the products of combustion collecting in the bottom. 

    -Combustion check.... was it EVER done? how recently?

    -CO levels' in combustion air...?

    -Pictures.... we love pictures here.

    Sorry Jean.. don't want to disagree.. but the combustion chamber does NOT need to be removed for cleaning.  Remove the front cover... use a nylon brush (I like engine cleaning brushes from the auto store)... and if necessary a spray nozzle hooked up to a hose on your water heater.  Start with the condescent trap and drain line.... make sure they run clear....  then start flushing all the sediment and silt from the bottom of the heat exchanger.  Once that's done, get as much out of the passages as possible.  Done. (obviously, reassemble the cover).
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    combustion chamber does NOT need to be removed for cleaning

    I know if you do the regular annual maintenance, you need not remove the heat exchanger for cleaning. OTOH, a vacuum cleaner will not do it. The passages are too narrow except at the top where the burner is.

    It was my impression that the OP had serious deposits in there that might require soaking in warm, possibly slightly soapy, water.

    When all done, you might wish to  clean the condensate trap again to remove the crud that is likely to collect there from the cleaning process.
  • ColoradoDave
    ColoradoDave Member Posts: 54
    edited November 2012

    That's an interesting situation you proposed Jean.. I've never seen a condensing boiler so fouled up that it need to have the heat exchanger removed to soak.That being said, I guess it is entirely possible... We ALL know people with high efficiency boilers get annual / semi-annual service like there supposed to .I'd never considered the possiblility of having to remove it to do so.  I chase my "high-efficiency" customers down if I haven't heard from them in 18-24 months.  When I get out there and the 18 month time frame isn't cutting it anymore with regards to cleaning, I start hounding them at the about the 12 month mark.Our business takes a slight down turn in early summer and I've managed to get all of my HE customers into that window for their annual/semi-annual maintenance.  Keeps the dust from gathering on the cleaning tool kit during the summer.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    We ALL know people with high efficiency boilers get annual / semi-annual service like they are supposed to.

    Of course they do!

    Well, maybe the customers of my former contractor do not. One of their employees said gas fired heating systems do not require maintenance unless something goes wrong. One of the reasons that is my former contractor. They budgeted 15 minutes for the service call, and he came with no gasket set, no combustion analyzer, and did not know if my W-M Ultra 3 was gas or oil. The easiest way to tell, it seems to me, was that cute "drip leg" on the black pipe bringing the gas to the boiler. All the oil burners I ever saw used 1/2 inch copper tubing for the fuel supply and had an oil filter in the line. But, not being a contractor, I see only those of friends. They are mostly cheap forced air gas units, but two are oil.
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