Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Correct Nozzle Size for Peerless Boiler TW-3

Whalensdad Member Posts: 2
I have a Peerless TW-3 from the late 80's (I'm guessing since you can't read the serial number). The service placards from the early 2000's show that the nozzle size was .65x80b. At some point it was changed to5x70b. I'm trying to keep this thing running as long as possible. I just had an issue and the tech noticed the insulation starting to burn. He thought it might be to the use of the .75x70b nozzles. I'm planning on doing an overhaul of the unit (new insulation, new tankless coil, and new igniter). I contacted the Peerless Boiler Company, but they indicated the following:
That model would have been manufactured by a former company, not our company. Unfortunately, we would have no information to provide. Our company, PB Heat, LLC has manufactured the Peerless® brand since 2003; prior to that date the company who manufactured the Peerless® brand was The Peerless Heater Company who are no longer in business.

I'm trying to determine if an incorrect nozzle size was installed and if I should revert back to what was there in the early 2000's. For all I know, maybe the .65x80b was wrong. If anyone can tell me or point me in the direction to get an answer I would be very appreciative. Thanks!


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,386
    Which burner is on it? What’s the pump pressure?
  • dopey27177
    dopey27177 Member Posts: 887
    Usually when insulation on a boiler is burning the high temperature cement sealer between sections has been compromised or disintegrated.

    Once you pull the jacket check out the High temp cement sealer between the sections.

    HVACNUT Member Posts: 5,480
    Can you post a pic of the boiler. I think what you've got is actually a JOT-3. TW was a manufacturer code, not the model.
    The '83 and '84 blocks were recalled for draft issues. Even after, those blocks were a mess. The smallest brushes would get stuck. Are there even any pins left?
    We used to install the 3 sections with a Beckett AFG with an F6 head, .75 80°A, downfire baffle, 100 psi.
    You want it to run as long as possible. Everyone wants longevity out of their appliances but are you trying to set a record? Why? 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 6,763
    edited June 2021
    If you have a boiler that is inefficient and you do your best to keep it operating for as long as possible, you are doing yourself a disservice. Think of it this way: Say to yourself: "I know I needed a new heater 10 years ago but I want to waste an extra 50 gallons a year for another 10 years or as long as I can."

    After that is said, do the math (just an oversimplified version) 50 gallons x 20 years = 1000 gallons. What is the price of fuel now? $3.00 or $4.00? That is equal to 3 to 4 thousand dollars. add to that the cost of repairs and that rebuild you are thinking about, and the future repairs. If you do the simple math without accounting for interest earned on the savings over that time you were giving away those energy savings to the oil dealer, you will pay for a more efficient heater over time. But you just won't own the new heater.

    Just one point of view


    PS Edit
    If you decide to continue to use the inefficient boiler, you want to go with the smallest firing rate that will maintain at least a 400° (or 350°net) stack temperature.
    .50 GPH or .65GPH may be just fine. The .50 GPH may not provide enough recovery for domestic hot water. You will need to experiment with this. If you are not a DYI with combustion testing equipment, I would use the .65 GPH.
    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics