An event yesterday has prompted me correct my earlier post and apologise to Smev. As predicted, the lack of spark did pee me off enough for me to investigate it when I had to look at the underside of the unit for another reason. I traced the wire from the gas ring sparker (or whatever it's called) to the igniter and then found that it's white plug had not been connected! It took about 2 seconds to connect it and another couple of minutes to find a small tie wrap and secure it properly so that it won't come out again. I told my wife about it and she reckoned that it has never worked since we first got the van from the converters so I can only assume that they forgot to finish the job properly when they installed the unit.I can't answer the question on what unit is best but I can say that even a box of matches would be better than the piezo igniter on the RH gas ring of our 9222 which stopped sparking soon after we got it. It's one of those jobs that I simply haven't bothered to look at but eventually, it will pee me off enough to investigate and sort it out!