My furnace may be oversized. What can I do ?

Question

Furnace short cycles, new ductwork, digital thermostat. Drain line only 1/2" calls for 3/4". Direct vent out is 2" calls for 3'. Is this my only problem ? 100,000 BTU for 1500 Sqf. ( 92%)

Answer 1

Can't answer this question because we don't know the heat loss of the home,  or the number of degree days for where you live.

An oversized furnace usually isn't a problem. An oversized air conditioner is.

I wouldn't be concerned with the drain line, but I would be concerned about the vent. 2" is too short.

Answer 2

Check heat anticipater setting on digital thermostat.It should be at least set to 1 degree if it still short cycles move to 2 degrees and so on til it isn't short cycling.You shouldn't have to go over 3 degrees.The 2" vent pipe will become a problem.Had one that someone else installed with 2" vent instead of 3" and it sooted up the heat exchangers solid in 2 years of service.