I have no free kin idea what is going on this year, this past weekend with overnight lows in the 20's I was getting 16 to 18 hours on a 3/4 load. Today highs in the 20's, I left for work, came home 5 hours later and water temp down to 158, that's with half a firebox load.
Cleaned heat exchanger, nothing. Put another half load in, gassing like a jet engine, you can hear it from 20 ft away, turned air settings all in, still a flamethrower. Figured what the heck, stuck 6 turbulators in.