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Baxi Luna 380 pressure drop

raylight Member Posts: 2
Hi, We have Baxi Luna 380 combi boiler. The pressure in the boiler keeps dropping and I see the regular discharge from the pressure relief valve pipe which causes the boiler pressure to drop and display E119 fault code. I then have to increase the pressure manually through the knob underneath the boiler. Can someone please suggest why the boiler is loosing the pressure so often and can someone please suggest a qualified baxi plumbing contractor in greater boston area? I am finding very hard for any plumber to work with Baxi boiler.


  • Zman
    Zman Member Posts: 7,607
    A bad expansion tank is the most common cause. I think the Baxi has one built into the cabinet.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Tom_133
    Tom_133 Member Posts: 893
    Zman is spot on, typically installers rely on the red "pancake" style expansion tank to do the whole system. That is a mistake, that internal expansion should be used only for the boiler when making hot water, and an external expansion should be used that will be used during heating production. If you have both they both need to be checked and replace whichever is bad or both if they are both bad and the leaky relief valve. Where are you located?
    Montpelier Vt
  • raylight
    raylight Member Posts: 2
    Thanks Zman and Tom. I am in Chelmsford, MA. I would get the tank checked if I find a plumber who knows about Baxi boilers.
  • superdave
    superdave Member Posts: 155
    Yes I also agree it sounds like expansion tank need to be checked out. I would also just replace relief if you have the system drained down. Is the relief valve facing up or on it side?? You want it to be up from any debris from getting stuck on gasket. I am out of Quincy, Ma. so if you find someone closer to you and needs help over the phone please let me know.