Many of the computers are more simple many are not. There is also the dreaded "lock-out" where the computer shuts down the boiler for no reason at all, and you call the repairman to fix it.

You also said it yourself, the "epic" failed. The more complex it is, the more it has a need for what I called "routine maintenance," maybe mistakenly so. These things need annual "tune-ups" costing a few hundred dollars. An 80% furnace or boiler does not have that requirement.