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Cost to clean a heat exchanger?

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Comments

  • Evan0307
    Evan0307 Member Posts: 27

    @mattmia2 It is a gravity conversion yes. The original pipes are pretty big, maybe 3 inch or 4 inch pipe, not sure. Of note, there is a circulator delay built into the hydrostat and I do use that. The circulator delay keeps the circ from coming on until the boiler is up to at least 125, then the circ starts. If the water temp falls below 115 it will initiate circ. delay again.

  • mattmia2
    mattmia2 Member Posts: 14,246

    that seems pretty low to prevent condensing and it probably shuts off almost immediately after it starts. there is a lot of mass in that system and you usually try to keep the return temp above 130f to prevent condensing.

  • Evan0307
    Evan0307 Member Posts: 27

    @mattmia2 Ill get out my manual and see if I can adjust that temp on the circulator delay.

  • clammy
    clammy Member Posts: 3,232

    Wrong installer a truly competent hydronic installer would and should have known better and would never had direct piped it or even if it was primary secondary piped would have included a system by pass ( the cheapest ) or a simple danfoss thremic valve should have been done. The issue might have been that the guy who suggested it may have been the only one w a clue and having a clue entitles one to charge more due to the skill set but it does not mean that he will get the job . I toss it out there that just cause ya can press or solder a joint by no means ya have a clue ya just got the tools and maybe some skills .There a million dudes out there just cuttem and toss em in and then later scratching there heads later or don't return calls and don t discount the public utilities for the same . LOL

    Now a day if the cover of your book is not up to perceived notion or u are not projection the image of who they want to see your done which in my case is just fine and dandy by me .

    perception very funny concept

    As always remember peace and good luck need more of both these days

    R.A. Calmbacher L.L.C. HVAC
    NJ Master HVAC Lic.
    Mahwah, NJ
    Specializing in steam and hydronic heating

    mattmia2
  • dandub1960
    dandub1960 Member Posts: 19

    Besides the tech being uninformed, I think what we can conclude from these numbers is that between combustion excess air and dilution air you've got 79% of your total exhaust is entrained air. That seems like a lot. 4 times the combustion products. Maybe others can comment on that. Maybe that's just the way it is. Im guessing it wasn't particularly cold yet when this testing was done.

    Also undiluted CO in the boiler could be as high 1700 ppm, if you trust this tech to operate his gas meter properly, sample point notwithstanding.

  • Evan0307
    Evan0307 Member Posts: 27

    @dandub1960 @mattmia2 @HVACNUT @EdTheHeaterMan @Alan (California Radiant) Forbes @captainco

    I wanted to follow up on original post because I appreciate everyone's help and wanted to thank you. I had the original installer of the boiler come out and ran another combustion test (results in image). Tech took the sample from under the draft hood. We also discovered a little nozzle looking piece on the ground next to boiler. I believe he said it was an orifice that goes over the pilot burner, and without that orifice on there the pilot would be burning unrestrained and could give some crazy numbers in a combustion test. So basically the tech who took the original test sampled from wrong location and did not reassemble all the parts!

    IMG_4981[1].JPG
    Robert_H
  • HVACNUT
    HVACNUT Member Posts: 7,016

    338° is a little low which likely means the boiler didn't reach steady state. The numbers are better than before, even if it can't be used in court with a 2022 date.

    Is it possible the pilot orifice found is for an LP conversion? I find it hard to believe a pilot would be stable enough without an orifice that you wouldn't notice it. Did the original tech know how to adjust a pilot regulator, but didn't know how to perform a proper combustion test? Did the second tech remove the pilot assembly and install the orifice that was found?

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 18,598

    Those combustion #s are OK.

  • Evan0307
    Evan0307 Member Posts: 27
    edited October 5

    @HVACNUT I didnt notice the date but I was with the technician this time around. I was not with the first technician (different company) for the first test so Im not sure as far as the orifice. My guess is he disassembled everything to clean and forgot to put that piece back in. The 2nd company was the installer. He put the piece back in where it goes. As far as temperature, we let the boiler run for about 15-20 minutes so it probably didnt get as hot as it would in the winter. It was an 80 degree day when we did the 2nd test.