As far as
The burners themselves, the Beckett is by far the most popular, the new thing is the Reillo, it is, according to everything I have read, the cleanest burning unit out there, I have no personal experience with one though, I worked on Becketts in the 89s and 90s when they were the latest things, they are all ok, same goes for a Wayne or Carlin, but personally I still would rather have a old unit, mainly because of the quieter operation, the old burners ran at 1725 rpm, the new ones at 3450 rpm,of course the manufacturers claim all sorts of savings by changing to one of the so called "Flame Retention" burners,which all the new ones are, basically flame retention is the design of the nose cone, which is the front of the burner where the nozzle is, and where the flame burns, the nose cone on them is designed with smaller slots to increase the velocity and turbulence of the combustion air in such a way that the flame burns in a smaller area at a hotter temperature, I personally think it was to make smaller combustion chambers practical as the more compact flame pattern is great for this...this means less metal can be used in the furnace, also , a pump and motor running at about twice the speed will of course wear out faster and that means more money for the manufacturer...as far as hot air furnaces go, their is not but 2 on the market I would consider, and they are OLD OLD OLD designs that have not been cheapened, first choice would be a Thermo Pride, second a Hallmark, basically ,other than the burners and combustion chamber, they are the same exact furnace that they made 50 years ago, identical heat exchanger, cabinet etc, and the main thing is you can order whichever burner you want on the Thermo Pride, AND you can still get a belt drive blower which to me is still the best way to go, I despise a direct drive blower, they are noisy and much harder to clean..as for boilers..your guess is as good as mine..I will say I want to see a Reillo burner, they really look interesting, but down here no one knows anything about them, so it would not be advisable to get one unless you had a good dealer service network.