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Baxi Luna 310 FI Primary Exchanger Leak

Bryan96 Member Posts: 5
edited June 2017 in THE MAIN WALL
The primary heat exchanger in my Baxi Luna 310 FI has a small leak that's located on the front side of the left (my left while looking into the boiler) edge. It's dripping outside of the heating chamber at about 1 drip every 2 seconds. It only drips while running the radiant heat, not the DHW. The heating tech that changed out my secondary heat exchanger for the DHW said that when the primary heat exchanger starts to leak there is no way to fix it and you just have to replace the whole boiler (He took measurements of the rooms of my house so he could give me a quote on a replacement). I found that the part is available for around $570 and I have my doubts about this guy so I'm going to try to replace it myself. I'm not a heating technician or plumber but for a point of reference of my mechanical skills, I'm capable of doing automotive work like exhaust repair, radiator/coolant pump/alternator/power steering pump replacement, brake job, and ignition timing and repair.

Are there any pitfalls to worry about when replacing this part?

Do I need any more parts (like gaskets or fasteners) than just the heat exchanger when changing this out?

Any other guidance or suggestions are highly appreciated.



  • kcopp
    kcopp Member Posts: 4,441
    How old is this unit?
    Sometimes pulling apart one section of a wall hung unit creates issues elsewhere?
    I would be hesitant to put too much time and effort into this unless you are confident in your not going to have more issues this winter. Is the boiler piped properly?
  • Bryan96
    Bryan96 Member Posts: 5
    "How old is the unit?"
    The boiler was new when the house was built almost 10 years ago.

    "Is the boiler piped properly"
    I'm not sure what you mean. It comes on when the thermostats call for heat and it sends heat to those zones until the thermostats stops calling for heat, and it heats water for the sinks and showers.
  • lchmb
    lchmb Member Posts: 2,997
    any thought of a warranty? Maybe a reputable company can check to see the cause so your not wasting a lot of work on something that isnt worth fixing.. I believe if you check the supply house they will give you the basic parts needed to replace the HX. Once done though you need to have the unit "set up" properly with a digital analyzer. I personally wouldnt put my name on something like that due to liability. I'm not questioning your ability, just your knowledge. There are a lot of things that can go wrong and the outcome could be deadly..
  • Bryan96
    Bryan96 Member Posts: 5
    Thanks for the response, lchmb.

    I never even considered that it may still be under warranty. It would surprise me if there was a 10 year warranty on it. Is it normal in the industry that units like this have long warranties like that?

    Do you know for a fact that the unit has to be set up again if the primary heat exchanger is replaced? If so, do you know if it has to be set up again if the secondary heat exchanger (the one for the domestic hot water) is replaced? And also, what about the circuit board?

    The reason I ask about the secondary heat exchanger and the circuit board is because both were changed by the technician and he didn't do any set up procedure, he just turned it back on and bled the air out. The reason he changed the circuit board is because he let a bunch of water get into the front control panel while changing the secondary heat exchanger and it ruined the circuit board.

    Thanks again for any info.