We often leave the pets behind and people come in an out to take care of them several times a day. We probably drop it 5 or 10 degrees at most. I guess it's personaly preference. I just hate to come back and turn it back up and potentially wait 3 hours for it to warm up.
It all depends on 3 things:
b. the inconvenience of turning up the heat when coming back
c. any valuable items in the house
I am personally not too concerned with the time it takes to heat it up. When returning from vacation, if house is too cold then go home, turn the heat up. Go for a restaurant for dinner then come back. Should be OK after dinner (if it was at 58-60 F).
1. For a typical home with some valuable items like: good furnitures, piano, then it is a good idea to keep some min temp like 58-60 F. It is a good compromise between cost of heating and potential damage to valuable items.
2. Some people are short of budget and have no valuable items let's say in a log cabin, they drain all water out of the house system, and turn the heat down to 45-50F or even turning it off completely (I don't think you should turn it off completely even if you drain the water because there is always some water in the line just BEFORE the water valve that can freeze).
(During the northeast power outage a few years back, my brother did the exact same thing, drain all water and lived elsewhere, there was no power for 3-4 weeks in Montreal Canada in ? around 1999).
3. Different topic, but when on vacation, I always turn the main water valve in the basement off. Never know one of the water supply rubber hose (like the one for washing machine) bursts, I have friends who had this happened....$30K damage.
These rubber hoses should be replaced every 7-8 years anyway.
OK I'm officially confused, in my post a few below this, regarding a condensing furnace, Milk Man told me not to set my furnace in my workshop to 50 degrees as it will corrode the heat exchanger if it's not Stainless Steel. A number of you are indicating here it's OK. So is it or isn't it? Are SS heat exchangers the exception or the rule? For my purposes, I'm only concerned about liquids freezing and rust on my tools. It's worked OK for me for years with the wall furnace I have but it's not a condensing unit.