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Baxi luna 310 fi problem

Rickster Member Posts: 2

i am having problem with my Baxi luna 310 fi. i'd appreciated it if you can give me some help on my problem.

basically my boiler is working fine, but when it is set to heating mode,

for every 10 to 20 minutes, there is a weak spark (like only 3 sparks

instead of a lots of 'tickings' for a normal start) and no flame is lit,

then the fan or flue fault light comes on, 2 seconds later, fan turns

off, and a no flame fault comes on too. if i reset the boiler, it will

work until the aforementioned behaviour repeat, and i have to reset the

boiler again for heat or hot water.

i observed it a few times and below is the sequence of events:

- heating mode, after many times of flame off and ignitions to maintain water temperature for heating

- water temp dropped and trigered a flame on command

- rely on PCB clicks

- fan came on

- APS clicked, indication of pressure differences = fan worked fine

- PCB commanded spark

- weak spark, only 3 spark incomparison to many for a normal start

- fan or flue fault light came on

- no flame fault light came on

- 2 seconds later, fan turned off, APS clicked to indicate fan was off

if i reset the boiler, it will work fine until the above events are triggered.


  • Alan (California Radiant) Forbes

    Have you tried to call Marathon, the USA rep.?  (800)461-4657

    The last Baxi I worked on the fan was working and the fault lights would come on almost immediately.  I finally tracked it down to a melted venturi in the flue.
    8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

    Two btu per sq ft for degree difference for a slab
  • Rickster
    Rickster Member Posts: 2
    RE: Venturi melted


    thank you for the idea. but my Baxi works for a duration of about 15 minutes, then the faults come out. so i don't think it is the venturi in the flue. plus it works again if i reset the pcb.

    i haven't contact any Baxi service people yet, because i know they will just ask me to change the pcb and see if the behavior is the same. and the pcb is kinda expensive for a try.
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