We're having the same problem with ours and have had a series of plumbers out to look at it. Seems it could be the air setting (which it's not in our case), or a blockage in the air inlet or outlet, or it just needs replacing. If you've not had it serviced recently it could be that the electrodes or spark plug need replacing. We're in France though, and they are very unfamiliar with Ecoflam...
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