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Looking for the size of an O-Ring for the MZ 25 burner

Tomato
Tomato Member Posts: 21
Recently the flue gaskets (now replaced) and an o-ring decided to fail. I have since found that the o-ring is about 1.5 inches ID, is Nitrile, and metric sized... oh, it is also not called out in any parts lists including the "for reference only" list. The burner's nozzle is about 38.4mm OD.

Since the o-ring went to pieces I have not been able to measure it. I did find an o-ring of about the right size but while it seals the gap it does not do the job.



What job you ask? It is supposed to keep the blower in place. The blower balances on a elastomeric pad and is held in place on the burner's nozzle by the o-ring. In order to accomplish this feat the o-ring fits in between two parts of a Teflon adapter between the aluminum blower and the stainless steel burner.
Otherwise it is a friction fit on the burner's nozzle. The vertical line in the Teflon adapter is where the two parts join. It is a tight fit but there is some lateral play between the two parts. A thicker o-ring could easily fit in the space between the two parts of the Teflon adapter.

Presently, the blower is wedged between a plastic cup against the indirect tank to hold it into the burner's nozzle.

If it wasn't so cold I would take the burner and blower adapter to a supply shop and find the o-ring.

Budny Fuel Oil Company, and Stayer don't have them in stock, nor do they know the size.

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 13,119
    First try the equipment manufacturer. I don't know what an MZ-25 is.

    If you stike out there I would look up McMaster Carr on line
    Tomato
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 13,119
    Are you without heat? Maybe seal it with silicone temporally untill you get the O ring
    Tomato
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 4,941

    Are you without heat? Maybe seal it with silicone temporally untill you get the O ring

    Duct tape
    Edward Young Retired HVAC Contractor & HYDRONICIAN Services first oil burner at age 16 P/T trainer for EH-CC.org
    Tomato
  • Tomato
    Tomato Member Posts: 21
    Thanks for the comments.
    1. We have heat no problems, but the cover is off of the boiler and having a plastic cup holding things is not my idea of a repair.
    2. Silicone is a more or less permanent connection and the blower has to be removed annually to flush out the firebox.
    3. Duct tape is not designed to work at these temperatures and differences in elevation. Plus it is not good under constant tension.
    4. https://duckduckgo.com/?t=ffnt&q=mz+25s+boiler&ia=web