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Weil-McClain PILOT orifice

Gary_24
Gary_24 Member Posts: 39
edited October 21 in THE MAIN WALL

Hi all,

I have an older Weil-Mclain PEG-40, natural gas, 125,000 btu with spark ignition and mercury flame sensor. Does anyone have a part-number manual that includes the electronic controls, ignition, Pilot etc. The only manual I found online has only the sheet metal, boiler sections and related parts.

I'm trying to find What the gas Pilot orifice size isand Part Number for the orifice ?

Thanks.

Comments

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,212
    edited October 25
    Screen Shot 2024-10-21 at 8.30.55 AM.png

    Note 1: Order sufficient quantities to replace all orifices within a base.

    Page 33 of the manual:

    chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.weil-mclain.com/sites/default/files/field-file/eg-peg-egh-series-4-manual_1.pdf

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Gary_24
    Gary_24 Member Posts: 39
    edited October 25

    Thanks for the reply, my original post wasn't clear enough, but those are the manifold burner orifices, not the pilot flame orifice.

  • Alan (California Radiant) Forbes
    Alan (California Radiant) Forbes Member Posts: 4,212
    edited October 25

    Sorry, your post was very clear; I missed the key word.

    I don't think the pilot assembly is a Weil-McLain part; probably Honeywell and I don't know where to find the orifice size. And I don't think they sell the orifice by itself, but I've never looked for one so I may be wrong. You might have to buy the entire pilot assembly.

    Screen Shot 2024-10-21 at 9.19.17 AM.png

    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
    Gary_24
  • Gary_24
    Gary_24 Member Posts: 39
    edited October 25

    Thanks again. Yes, I've found an original, NOS, White Rodgers E50-104 Pilot burner electrode assembly on ebay, but they don't come with a new pilot orifice.

    New Pilot orifices are available, but I want to make sure I purchase the correct one.

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,312
    edited October 21

    This page might help

    Screenshot 2024-10-21 at 2.21.51 PM.png

    WM used the WR cycle pilot on several of their gas boilers, the natural gas pilot orifice is pictured as #3 if you click on the screenshot you can zoom in. It has a .020" diameter orifice and that is a little larger than standard orifice for Honeywell, WR and other manufacturers. If you use the WM part number 560-528-958 at the supply house you can expect to pay triple. Just ask for the natural gas orifice that fits on the end of the 1/8" pilot tube. That should be all you need if your counter man has any experience.

    This one may fit https://www.supplyhouse.com/Resideo-390686-5-020-Natural-Gas-Orifice

    If that is not the correct shape than try this one https://www.supplyhouse.com/Robertshaw-10-208-022-Natural-Gas-Orifice-for-Robertshaw-1820-1830-Series it is only .002 diameter larger and should be fine

    Those are the two different orifices that slide over the 1/8" pilot tube that I remember using.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • Gary_24
    Gary_24 Member Posts: 39

    Hi, Thanks for the reply. My Pilot Burner Electrode Assembly is E50-104, photos attached. It appears that the gas tube threads into the orifice. I found one which I believe could be the correct part, but I want to confirm the part number before I order it, attached here are two photos of what could be the correct orifice that I'm trying to confirm.

    IMG_4014.jpeg
    IMG_4015.jpeg

    Pilot assembly

    IMG_3992.jpg
    IMG_3993.jpg

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,312
    edited October 21

    Weil McLain charges too much. and that WM part number does not have the electrode for the sparker. It is for standing pilot burner only. This one looks a lot like yours https://www.supplyhouse.com/Baso-Gas-Products-Y90AA-3223-1-4-Inlet-Fitting-w-023-Orifice-Natural-Gas. It has a .023 orifice

    Will keep looking for .020

    Here is a .021 orifice https://www.controlsincgas.com/Product-Name/Y90AA3221

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    Gary_24
  • Gary_24
    Gary_24 Member Posts: 39

    Thanks! I am going to disassemble my pilot assembly to see if there is a size stamp or marking on it to confirm.

  • mattmia2
    mattmia2 Member Posts: 10,845

    Why do you need one?

  • Gary_24
    Gary_24 Member Posts: 39

    I'm installing a new Pilot assembly and would rather not reuse a 25 year old part if i can avoid it.

  • mattmia2
    mattmia2 Member Posts: 10,845
    edited October 22

    Measure the old one. It is just a piece of metal with a hole in it, it will last well over a century.

    What you should be worried about is that the mercury flame switches are not quite obsolete but the new ones are super expensive and tend to be unreliable.

  • Gary_24
    Gary_24 Member Posts: 39
    edited October 25

    I found and bought an original NOS Pilot assembly on ebay , made by White Rodgers for Weil-McClain. It has the same part number as my original, with the spark ignitor lead installed, and it comes with a new pilot orifice as well so I'm good to go!!! The pilot orifice has 2090 stamped on it.

  • HeatingHelp.com
    HeatingHelp.com Member, Moderator, Administrator Posts: 65

    @Gary_24, I've merged your duplicate discussions into one here to prevent confusion.

    Forum Moderator

    Gary_24

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