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ultra 155

KenNotz1 Member Posts: 2
I have a Weil-Mclain ultra 155 boiler . I have had 3 different heating companies come fix this boiler and 8 thousand dollars later and it still isn't heating up. Everything is new on it. The computer board even has been replaced. The only thing that has been replaced is the heat exchanger. It works but the outlet water will only get up to 150 degrees and when the domestic hot water kicks in, It take about a 1/2 hour to heat it up and when it switches back to #3(house heating) it will have cooled down way to much and it gets an error
code b-30 which is inlet water temp 58 degrees colder than outlet water and will have keep resetting it till the water heats up enough. So here's my dilemma the flame ramps up to high fire for 4 seconds and quits the temp modulates between 134 degrees and 150 degrees. I need the flame to stay on longer to heat the outlet water for my radiators to at least 170 degrees so when it switches over to domestic water heating it won't cool down and get the error b-30 . The second heating company had a Weil-Mclain tech come down and got it to where it is now. The 3rd heating company guy came in and looked at it and said sorry can't help you and left. This boiler from hell is in my apartment building and I have to babysit it to make sure my tenants don't freeze with this cold weather here in Iowa. Is there a reset code or way to get the flame to run longer?


  • ch4man
    ch4man Member Posts: 296
    this sounds like a near boiler piping issue. can you post some pictures of the boiler and piping from a distance so we can see the installation?

    how many zones/apartments are there? how is it zoned, pumps or zone valves?
  • Boiler wrestler
    Boiler wrestler Member Posts: 43
    How many square feet is the boiler heating. 30 minutes is a long time for the boiler to be heating domestic hot water. I suspect this boiler is at least five years old, has this been a problem the entire time?
  • Ironman
    Ironman Member Posts: 7,379
    Those pics ar so fuzzy that I can't make heads or tails of them.

    Please take a couple of clear pics from farther back that show the boiler and all of it near piping in one or two shots.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    Page 11 shows the required typical piping diagram.
    While you are babysitting the system, compare the piping layout of what you have with what is needed, paying attention to direction of flow, marking the pipe with arrows, and checking the arrows on the pumps.
    Did the system ever work properly?
    Don’t forget the pictures!—NBC
  • Leon82
    Leon82 Member Posts: 684
    They make and sell a prefab manifold with dhw taps and
    proper p /s spacing. Between the 3 of them someone should have came across it