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RMB pump cartridge

The Taco RMB has two pump cartridges which are designed to be replaceable parts so maybe they wear out. How do you know if one of them needs to be replaced ? What is the symptom of one of them being broken ?


  • Leonard
    Leonard Member Posts: 903
    edited February 2019
    I just had an old school circulator failure.
    I was just looking at design of wet rotor pumps. I'ld say except for not leaking same symptoms as old school circulators:
    --- your radiators/baseboards don't heat as well
    ---or get and stay cold.
    ---Or motor short cycles ( bearings bind, overloads, thermal protector cycles) .
    While boiler is hot ( can fire) .

    Plus is Seems don' t have to oil the wet rotor ones
  • JohnNY
    JohnNY Member Posts: 3,230
    One pump moves water from the heating supply and back to the boiler while the other one moves water through the heat emitters. If one of those processes stops happening effectively, and programming or air is not to blame, you should suspect the RMB pumps have stopped doing their job.
    Contact John "JohnNY" Cataneo, NYC Master Plumber, Lic 1784
    Consulting & Troubleshooting
    Heating in NYC or NJ.