I need some advice on whether to have the early model burner, 87181206190 replaced with the same part number Mk 5 type. I have my annual service due in a couple of weeks, and while booking it with the guy who did it last year, I remembered that he had commented about the burner being the old type. The perforations are different in the current type. The boiler, however is 11 years old and although it has been 100% reliable so far, it must be coming to the time when anything that needs doing other than routine servicing would not be worth it. I could buy one of the later burners in time for him to install at the service, but would it be worth the £25 cost even at the higher prices of gas today, and would it even be more efficient?