I live in Nc where the winter nights can get into the teens on rare occasions.
I have a pipe on an exterior wall that can tend to freeze a little. I usually drip it to keep it from freezing on really really cold nights. Or if I forget, it may simply take a few seconds for the water to come on. My fear is when I'm on vacation (weekend or up to a week).
I plan to turn the water to my house off and run the faucets (both hot and cold) to get the water out, then turn the faucets off. I will not drop my heat below 60. I will turn my water heater to pilot.
Am I forgetting anything.
I have a gas water heater in my unheated garage, will this cause any damage. Will it freeze with the little water left in it?
Thanks for any advice
Ray

You should realize that in order to drain a water pipe you must let air in to replace the water.

Turn off water at the main valve.
Open all faucets, including hose bibs on the exterior. Air will enter the cold water faucets and the water will drain out the exterior hose bibs.
Flush all toilets, hold flush valve up until tank is completely empty.
Dip and sponge all water out of the bowl.
Pour a cup of cooking oil down each drain and in each toilet. Pour a cup in the bowl and tank of each toilet unless you dipped and sponged out all water.

Open the water heater drain valve and drain about 2 or 3 gallons. Air will enter the hot water faucets and the draining of water out of the water heater will siphon the water out of the hot water pipes.

Leave water heater on and turn to lowest setting. Turning off completely makes freezing possible. You could completely drain the water heater and turn off but you must remember to refill before relighting.

So this pipe that can freeze does so while you are living there in normal interior temperatures?

Yes, it has never frozen solid, but can take 5-10 second for water to flow the morning after one of these recent very cold nights. I've never had to thaw it, it has just started running after 10secs of water running. (its only happened twice, when temps were in single digits). The pipes I can see are insulated, but my fear is they run down an exterior wall and that area (and/or pipes in that area) may lack appropriate insulation.

If it can freeze when your inside temp is normal it surely could freeze if you lower your heat to 60. You have a problem with insulation and pipe routing but that is for another time. Opening your faucets does not insure all water will drain from that pipe. It might but you can't tell so you would need to blow out the lines with compressed air. Your toilets and traps should be fine with no issue as long as the home is at 60. My concern is that water heater in an unseated garage. With not use age the pipe filling and the pipe draining that heater could freeze no matter what you set the heater temp at. I would wrap both pipes with heat tape which can be bought at most home centers. The tape only uses electric power when it senses near freezing temps on the pipe.
BTW, I have a cabin sitting in near zero degrees and we set the temp at 50. Toilets and traps have never frozen.

Concerning the water pipes that sort of freeze. I had a similar problem and mine too were wrapped with pipe insulation and were on an outside wall. I finally took off the insulation, and placed as much insulation as I could between the pipe and wall, solving the problem. As the pipes get colder and colder, the pipe insulation keeps them from receiving any warmth from the house. I also agree with Ballengerb1 concerning the use of heat tape.

As far as toilets, do not drain all the water out of the bowl. The water in the trap keeps the sewer gases at bay. Instead of using oil as an antifreeze, use RV Antifreeze. It is clean and safe.