Yeah, some of the fly-by-nighter's run start-up "specials" for crazy low prices, only to either find some expensive repair you need or run out of town if you call with a problem. I see $39 specials all the time.
It isn't limited to startups or fly by night operators. The big billboard companies do it. It is done to get someone to the house to sell something.
Two are offering "no breakdown guarantees", at least that's what is advertised. Not sure what the fine print is, but I really doubt that the company will install a new piece of equipment or perform major repairs at a future date to fulfill that "guarantee".
Typical service calls now around town are $100-200 depending on if you're an existing customer are not. Plus it could be a week's wait. They don't pay enough to get enough skilled techs these days and so get stacked up.
Fixed the bold part for you.
Yes it can get confusing. For me gas furnaces are pretty much foolproof so long as they don't overheat (i.e. filter gets plugged up over time and the airflow gets much reduced). The (now) standard tube heat exchangers can be checked easily with the fancy new inspection cameras on the end of a flexible probe. I was almost to the point of getting one when I closed up shop.
The condensing furnaces with two exchangers get tricky. The main first stage tubes are usually not a problem - the secondary exchanger where the condensation forms tend to rust out faster. Don't know how to inspect those without disassembling the furnace.
Rust out? Really? Those tubes are made of stainless steel. Flue gas condensate is very corrosive, and most manufacturers will have a 20 or 25 year warranty on the heat exchanger. Now, other parts may fail, like the collector box. Lemmonox wants almost a grand for a piece of plastic and some foam gaskets. Yes, there have been bad designs that have failed, but generally speaking, the metals used in the heat exchanger will hold up if the equipment is installed and operating properly.
You don't inspect a heat exchanger, you test the combustion gases with a combustion analyzer.
I have seen those ads for those cameras. Just how in the hell are you supposed to inspect more than 10% or so of the heat exchanger without major disassembly? Sometimes, you can't even get a borescope camera head into the heat exchanger without removing the burners. And then get it through 4 additional tight 90º bends? Then the secondary HX (if the furnace has one)?. Who is going to pay for this time?
AHRI Guideline X provides a standardized test procedure for checking heat exchangers. You need a combustion analyzer. And a drill to make a couple of holes.
The "popped crimp ring scam"* is pushed by those camera companies, and that will NOT fail a AHRI Guideline X test procedure by itself.
*: and you can't see those popped rings without taking stuff apart.
One can get a combo smoke/fire/CO alarm and install it by the bedrooms. I tried selling them but customers complained I was just soaking them for money, so I stopped offering them and told people to buy one on their own. Had an addendum on my work invoices and had customers sigh them - then I was covered.
Low level CO detector.