Annual boiler maintenance

Anyone have a recommendation on someone to come take a look at my gas boiler and turn it on or the season? It’s only 3 years old so all should be well, but I’d just like to be sure. I had the people who installed it come last year but I felt it was a little expensive considering what the guy did which, at most, took 10 minutes. I thought about getting one of those HomeServe contract through National Grid, but it seems like it would be the kind of thing that covers everything except your problem. Anyone have an alternative or recommendation? Thanks.