Along with air conditioners, heaters have joined the ranks of the most indispensable household appliances -- because if we wanted to chop and burn firewood for heat, we probably wouldn't be on the Internet reading about heating systems. Having a heater installed -- and then keeping it properly maintained -- is the essential purpose of a heating company. But not all heating services are created equal; if you want your heater to be in good hands, you'll need to know how to tell the genuine article apart from the fly-by-nights. Fortunately, once you know the tricks, it's not that hard.
The number one most important thing about any heating services company is whether or not its paperwork is in order. You don't want to work with any company that can't show you:
It might seem like a niggling detail, but these papers are exactly the thing that separates a legitimate establishment from what amounts to a 'freelance heating tech'. Of course, that's not all you'd hope to see.
We mentioned having at least a single reference before, but that's an absolute minimum. It used to be hard to get a solid word-of-mouth about a business, because in a city of several hundred thousand people, the chances that one of your friends or family has interacted with a specific business before is fairly slim.
Fortunately, if you can read this right now, you have the Internet, which means you have access to websites like the Better Business Bureau, Yelp, and Angie's List. You can also just Google the company's name along with some stock disses like 'scam' or 'poor' and see if any significant stories crop up. It's harder to find definitive positive reviews, but given the nature of the Internet in general, a lack of negatives is actually a very strong positive sign.
Finally, you can ask the company in question about their policies. A solid company won't hesitate to offer you at least some form of warranty on their work. They might go so far as to offer a free return trip if something breaks within a week of one of their visits, or they may just offer a free inspection to make sure that whatever happened wasn't their own fault.
Whatever the case, in addition to all of the above, you should also make sure that you're comfortable, on a personal level, working with a given company. Sometimes, there's just a personality conflict, and you don't want to feel at odds with your heating services tech every time they stop by.