Know the application before choosing the product
This may sound bland, however I see this every day. The classic conversation is as follows.
Client: Moe, What do you think about XYZ equipment?
Moe: Its a good product however where are you planning to install it?
Client: I have a job, building, business, home, etc.
Moe: Well its a good product but the wrong product for that application.
Lets use the case of a combi boiler or indirect hot water heater. Without putting a brand on the pedestal, the product may be perfect for one application and terrible for another. The appliance may work a long lifespan when applied correctly and a short, maintenance filled lifespan if installed in the incorrect scenario.
The above goes for anything from faucets, to minisplit heat pumps. Boilers and radiant to forced air. Every plumbing heating and cooling appliance, fixture and part has an application. Miss use of the appliance in a manner that the manufacture or designer did not intend to have it used, and the product will fail miserable and cost lots of money to keep running.
This my friend is why brands and types of appliances get bad names. I have a line I always say when someone complains about a piece of equipement or brand.
There is no such thing as bad appliances, only miss installed and poorly applied. - Moe