Needs repair possibly the ceramic radiants are cracked and allow the flame to light at the injector I would advise you don’t use and either seek repair or get a new one as it’s dangerous
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Yes standard but he may have been stumped because they are not regularly seen out in the wild I only came across a couple in 40 odd years, so not surprised if he was unsure.
If loops is removed there would be two caps to attach to the open ends. Think you may find that the removal of filling loop will be if it’s external to the boiler