This isn't home improvement, per se, so please feel free to let me know if there is a better forum for this.
I have been told by two people, one of whom is a boiler repair technician, that it's not a good idea to set my nighttime thermostat temperature too far below what I have it set at when I'm awake. Neither gave me a satisfactory explanation - just vague "it shouldn't be done" sort of stuff.
My question is why? Will it cause damage to the boiler (~3-4 years old, natural gas) if it's set, say, 10 degrees F different? Will it cause damage to anything else in the house?
I have three zones (basement, first, and second floor). Basement is always at 60. First floor is 70ish while we're home during the day, and presently only 66 at night. I'd like to set it to 60 at night but have been nervous to do so. Second floor is where we sleep, so 66-68 at night is fine.