A pipe bursting due to a freezing condition when the house is 62 degrees means that pipe is not inside the condition space of the house. Was this pipe in an exterior wall? Was there insulation between the pipe and the outside sheathing of the house? Did you correct the problem? If you didn't it could happen again even if the house temperature is set to 72 degrees.

Turning off the main water supply when leaving the house for an extended period of time is a good practice any time of the year. Toilet tanks have plastic shut off valves that can fail at anytime. Any plumbing under pressure can spring a leak.

You can test your main water shut off at any time. Turn it off and then open any faucet. The water should not flow after the initial water trapped in the supply pipe comes out. If the water continues to come out then you should have the valve replaced.

If you have addressed the pipe bursting issue, then lowering the temperature is fine. I don't see a problem with the hot water tank and the boiler. The tank will still be full of water. The boiler water supply I would think is isolated from the main water supply. That is something that needs to be checked. You want to make sure the boiler is filled with water when it fires.

Thanks for the comments. The pipe burst was in the wall between 2 bathrooms but the pipe also went though a wall adjacent to an attic. The plumber did add more insulation but I don't know if it is enough.

The baseboard heat boiler is fed via a reducing valve and is a closed system. I can probably turn off the hot water heater.

The boiler/radiant heat would need access to water. It would be ideal for two main valves in this situation so you can shut off the potable water and leave the boiler on.

Ideally have someone look in once in a while. That's frankly probably a better solution than turning the water off. Note you can also get sensors to put on the floor in basement/lower levels to detect water leaks. Not perfect but might give you some piece of mind. The pipe freezing the cold winter was really a problem with insulation of that pipe, but you'd have to get it checked to be comfortable there aren't other exposed pipes in the house that might be vulnerable in cold snaps.

Leaving the water running has its own hazards and there is
no guarantee that the drip won’t stop.

I'd shut off the supply side of the water heater and turn
off the water heater. Will neighbors be
watching the house and do you have a service company at the ready with arranged
access to the home 24/7/365? If so, get
one of these

http://www.honeywellstore.com/store/products/honeywell-cw200a1032-winter-watchman.htm

In addition, get one of these:

Intermediate FreezeAlarm™ [FA-I-CCA] from Protected Home.
Maybe add their moisture sensor.

Both are a bargain compared to a damaged home.

Leaving a faucet dripping is an old wives tail - it will do absolutely nothing to prevent water from freezing in the pipes..

sktn77a, you have evidence contradicting this procedure?. If the water is dripping fast enough, and the water entering the pipes in the danger zone is at a higher temp than the air around the pipes, it is logical to expect the drip to keep the water temperature high enough to prevent freezing.

"Leaving a faucet dripping is an old wives tail - it will do absolutely nothing to prevent water from freezing in the pipes.."

I burst the same pipe twice (sink supply line on exterior wall). Thankfully the damage was minimal. Accessing it to insulate it properly would be a big job. I've since left the sink at a slow, steady stream any time we have extended stretches of temps in the teens. No bursts since. My water costs about a penny per gallon. I may let 5 gallons run over the course of 24 hours.

Have you ever seen a picture of a frozen waterfall? If it gets cold enough even running water will freeze.

Yes, mike, I have seen the beauty of a frozen waterfall. The OP said IF my furnace malfunctions... otherwise, I believe he's just looking for advice on strategy during non-crisis times.

I've seen frozen waterfalls in person as well as streams. It has to get well below the freezing point to reach the picturesque state.

"you have evidence contradicting this procedure?"

You have evidence supporting it? You need WAY more flow than a drip for the linear velocity of water in the pipe to be enough to stop it freezing.

How much flow do you need to raise the temp of a short section of "exposed" pipe sufficiently to prevent it from freezing? Every situation is going to be different, unfortunately.

"You have evidence supporting it?"

My own experience is enough evidence for me. I choose to run both hot and cold lines at a slow stream, not drip. Pipes have not burst again through multiple similar weather stretches and the cost of the water is minimal. 1/2" uninsulated copper pipes on exterior wall on Long Island, NY, FYI.

What might be the easiest way to show effectiveness is to monitor the temp of an exposed pipe in a cold period. It would not have to be at freezing temperature, but close would help. Test with water running and with water stopped and see what the pipe temp does.

I have two situations for which these posts are relevant. Two years ago, I returned from a trip on a Friday evening in February. The outside temperature was 8° F. The inside temperature was also 8°. I called my local handyman and he traced the problem to a failed thermocouple in the boiler, which he replaced for $1`0. Upon examination of our radiators, we saw puddles of ice on the floor, so it seemed like the radiators had cracked. The next morning, with a hair dryer, we were able to melt the ice and clean up. The weather prediction was for warming up to 50° by Sunday, so we decided to turn off the water and continue to thaw the radiators. Ultimately, we had to replace all of them (they were old fashioned cast iron radiators from the 19th century). It took three months to acquire new cast iron radiators, during which time, we had no heat. Of course, some of the domestic plumbing had also frozen and cracked, so we had no water either. Fortunately, the $25,000 repair cost was covered by our insurance.

If we had returned two days later, then everything would have melted, and we would have had a flood with ruined floors, ceilings, and walls. That's why I now turn off the water in the winter when the house will remain unoccupied.

The other situation is with our vacation home, which was under construction two years ago. It has a more reliable heating system: electrically heated hydronic in-floor radiant heat. Of course, any component of this system could fail, so we made sure the thermostat was WiFi-enabled so that we could monitor the temperature. The house is super-insulated so most of the time in the winter, the inside temperature is higher than the set point. But, if we have a power failure (which is very unlikely), we will know about it only because the thermostat won't be communicating any more.

As an experiment, last winter, I turned off the heating system (when I was there) and it took two days for the temperature to drop below 50°, even though the outside temperature was sub-zero at night. So, I feel that I have two days to react to a power failure.

I am debating whether or not I should turn off the water and drain the lines when I am going to be absent for an extended period in the winter. My plumber says no.

Your plumber's wrong. Here's a further option. Turn off the waterand open the faucets to reduce water volume and pressure. Do both hot and cold. If any water in the pipes freezes the pipes won't burst. You may have to warm up the house for water flow when you get back. But that's unlikely. Leave the taps open and just crack open the supply a little when you get back to slowly fill things up again.

I didn't mention that my water supply is a well, so I will also shut off the pump.

I have in-floor radiant heat in both the basement and main floor; I doubt that the basement floor will freeze. The same plumber recommends against adding antifreeze to the heating water lines.

Turn off the water and open the faucets to reduce water volume and pressure. Do both hot and cold. If any water in the pipes freezes the pipes won't burst. "

This is the best most people can do, but it didn't work for us. We have a faucet at the front of the garage; the supply pipe travels through the (unheated) garage attic and then down an exterior wall to the faucet. We turn off the water and drain all the pipes when we're not there but there must be a low point that water doesn't drain from because every year, the pipe busts at the same point. We installed a turn-off valve inboard of the offending point and basically don't use that faucet any more. We tried everything (including the drip) but nothing saved it. And this house is in southwest Virginia - not a polar climate by any means.

Pipes can certainly crack at low points where water does not drain from them. Sometimes antifreeze ( I think it is propylene glycol like for RV use.) can be added to the drained pipes and then they are drained again, to fix the low spot problem, or sometimes they are blown out with compressed air. It seems like that would be difficult to do effectively.

The basement actually becomes a source of heat at some point (local ground temperature), but in a modern house with insulation in basement walls and slab, the heat flux is going to be way lower than with an older home so maybe not so effective.

The plumber probably does not like antifreeze for more than one reason. It adds a maintenance task to check it periodically and them expense to purge the system when it needs to be replaced. The glycol breaks down forming acid. It also cuts heat transfer efficiency so you need bigger radiators and probably cuts the boiler efficiency under some circumstances. (You might have to lower the fluid flow rate.)

Mike, your boiler can tolerate no water pressure for long periods? I never really looked into it, but I think most have auto fill valves. Is your's set up in any special way for this condition?

I have furnaces not a boiler. My only experience many years ago is with a steam boiler. That boiler had a manual water fill.

I am not a expert, but I thought a boiler (not steam) is a closed system. Why would it require an auto water fill? How is the water lost that needs to be replaced?

I think you are correct. I got auto fill crossed up with air separators.

The next step after turning off the water and opening the taps is to treat your system like a sprinkler system. I'd drain everything and then open the closest tap outboard of the low area that bursts just a little. Add air pressure from a small compressor at a fitting you'll need to sort out possibly at a threaded utility faucet spout. That outboard tap should spit water and air until there isn't anything left to freeze. Sears has air compressors with small tanks.

We have a boiler and in-floor radiant heat. We also have auto fill. If there is a leak we do not want it auto filling so that valve is closed all the time. If we leave the house at any time of year we turn off the main water to the house. The boiler is fine for heating and hot water during this time. It has a safety shutoff that if the water level is too low it shuts the boiler down. This has never tripped. Leaving the auto fill on just guarantees a flood of your house if you have a leak even if it is closed system. Maybe there are some non-closed systems that you need the auto fill on for. The auto fill is only good for filling the system up at start up or after it is repaired or flushed. I recommend for any trip away that is overnight that you turn off your whole house water valve. Your boiler should be fine unless you already have a leak.

I am thinking the whole leave the faucet dripping thing was for the hot line and the cold was next to it. Probably the idea was that the heated water was enough to do the trick for both.

We installed a turn-off valve inboard of the offending point and
basically don't use that faucet any more. We tried everything (including
the drip) but nothing saved it. And this house is in southwest Virginia
- not a polar climate by any means.

sktn, look for an rv blow out plug, if you install shut off valves accordingly you can blow the water out of the line. I have a tee and a shutoff valve for blowing out my two exterior faucets, and the shut off valve for the exterior faucets is at the cold manifold. Overkill for my application (the lines are inside and frost proof faucets sloped correctly) but I like to do it for peace of mind. I cap the blow out the rest of the year as a failsafe.

Note: You have to blow from the inside/out, as most faucets these days are one way.

Thanks Vith, that's a really good idea. We installed the cutoff valve but, of course, that doesn't stop "low point" water from freezing and bursting the pipe.

wow! that's a lot of discussion. I thought I would get automatic email updates so did not check on the website.

Well..the two valve solution seems to be the best option however, it is too late for that. I have camera and wifi thermostat in the house so I can monitor it. Infact, last time when the pipe burst, I had left one un-attached camera on the steps and it just happened to capture the "niagara falls" live! Don't ever want to see that again.

I think I am going to turn off the main supply. If I leave it on and the baseboard heat conks out as it did one night when were sleeping due to thermocouple problem, then I will end up with frozen pipes. On the other hand if the system runs out of water, hopefully it will not ignite and the worst I will have is inside at the same temperature as outside but with no water in the pipes, hopefully they won't burst. I don't know if there is a low point where the water collects. But the second seems to be the lesser of 2 evils

"I thought I would get automatic email updates"

If you go to your Profile -> Advanced Settings, you have some control over how notifications are sent.

Good luck with your winter strategy!