When the heat-resistant and gas-resistant sealing material leaks due to aging, the sealing should be restored;
If the pipeline leaks due to sand holes, repair welding and tin tape sticking should be adopted to block it.
If the burner (combustion nozzle) leaks due to deformation or rupture, try to repair or scrap the whole machine.
The picture is not clear, and we can't see the relationship between the whole machine and the leaking part, so we can only give principled measures. Attached, it is suggested to ask gas appliance maintenance personnel to handle it.