Trying to service that boiler

As a first time homeowner, I have to learn a new skill every week. I do not miss living in a tiny, cramped home surrounded by neighbors cooking foul-stinking food, then what I do miss is having a landlord with a maintenance team that handled all the little troubles with the place. If there was a power outage or a running toilet, I just called the front office. Those days are long gone, because now there is no landlord, so any troubles that emerge I need to handle myself, or by hiring a professional. When my tepid water furnace broke down, I instantaneously turned to my most trusted resource – Youtube. I knew that calling a furnace repair company would cost currency just to get an inspection and an estimate. I could not afford that at the time, so I needed to suss out the concern with the water heater, and then determine if it was something I could fix. I spent a couple of hours watching basic tutorial videos online, so I could figure out what make and model of water furnace I had. Then I got more particular, and watched videos about how to troubleshoot the most familiar troubles acquaintanced with my brand of water heater. All of the videos I watched were sponsored by several water furnace companies that showed ads about their newest models. I think I got brainwashed, because after a while I stopped wanting to service the aged water heater, and thought about just buying a new a single. I think a new tankless water furnace would be nice to have.