Frozen pipe question

Something was wrong with controls on that heater to do that, or the way it was started. An oil fired water heater is quick, but not quick enough to cause that problem.

If the water heater was not full of water when the burner was started, that could have caused the difficulty.

Now to your more general question. There are only two ways to be really safe with an empty house in freezing temperatures. If you know the house is going to be empty from late fall to spring, drain all the piping — heating system and domestic hot water. Make sure it is really drained. No odd pockets! Turn the electricity off at the main switch panel. If you have gas, turn that off outside. Then, when you go to turn things on in the spring, make sure that the domestic water is running at all use points, hot and cold, and then turn on the hot water heater. Make sure that the heating system is refilled and purged, and then turn on the boiler.

The other approach is somewhat simpler — and has the additional advantage of catching such oddities as broken windows, trees on the roof, and such nuisances. Pay someone reliable to look after the place and, if possible, leave it running at a low temperature (the summer places we care for run at 50). This is not a drive-by job for a neighbour: this means that whoever you hire comes by frequently — once a day in colder weather — and goes in and pays attention.

 I was told that leaving everything on and letting the upstairs faucet drip "Should" be sufficient.

Every house is different, so there is no "should." The problem, as you learned, is that leaving the water on is a high-risk strategy. The lowest-risk strategy is to turn everything off and drain your pipes, even that runs the risk that the draining wasn't done properly and some water remained and froze. Turning the water off and leaving the heat on is pretty low-risk, although you run the risk of the power going out and the heat going with it.

There's not even a thermostat setting that guarantees your pipes won't freeze. I'm in Washington, DC, which thinks of itself as a southern city even though it gets pretty cold in the winter, design temperature is 21F. But plumbers run pipes in exterior walls all the time, and when it gets cold pipes freeze all over town in heated buildings.

A lower temperature setting indoors is fine as long as it protects the building. So, as to what @Mad Dog_2 says above. Do that and heat it right.

The other thing you can do is add a snifter valve at the incoming point of your water main and blow the water out with an air compressor and leave all of the faucets open. Ideally, you should have the water shut off at the street if that applies to your system.

Another good thing to do is add nontoxic antifreeze in the drains where traps and other standing water will be. This can help prevent freeze-ups in the drainage system.

I drain my pipes every winter ( I winter in a second location ). I use compressed air ( 50 lbs and large volume ). I roll in my shop compressor and hook the air line to the thermal/pressure relief valve on the water heater which is a common point for both the cold and hot water lines. I cycle open/ closing the faucet valves through the house till I get mostly air coming out. I use my wet vac to drain the sumps on my clothes washer and dish washer and of course antifreeze in the traps. No failure yet.

Back in 2008 when tons of mountain properties were in foreclosure the banks were paying contractors to "winterize" the properties so they did not have to pay for heat. None of these winterizations were successful and the repairs ended up costing far more than the utilities would have. Unless the house was designed to be drained down or you are a highly skilled plumber, it won't work to drain down the pipes.

I would suggest fixing your hot water expansion tank issue and just turning off the water when you leave. You may have a few frozen pipe issues at first, but will avoid expensive flooding.

The OP is not an experienced plumber and is looking for solutions to his problem. I am sure you can effectively do this but doubt he has the time or skill to do this every time he leaves town. He stated that he just wants to turn the heat down and does not want the T&P to blow off on the water heater. I think fixing the exp tank issue and turning off the water is a good solution as long as the heat is still on.

We leave our farmhouse in the winter in upstate NY. Mercury drops to below 0 frequently up here. So we replace the water in the lines by pumping RV antifreeze into the pipes. We shut off the well pump and since that's below ground it never drops below 45 degrees. We then move upstream from there and attach a small pump and begin pumping in the antifreeze from 5-gallon buckets. We run the washing machine until we see the colored antifreeze come out, and then the dishwasher, the toilets, showers, etc..you get the idea. Works pretty well for longer-term winter vacancy. We can also shut off all electric devices like the fridge, etc to save from having any electric bills during the winter as well. I visit the farmhouse 1-2x monthly during the winter. I just isolate one toilet and use hand-pumped water to use that. Before I leave I put antifreeze in the tank and bowl. Cheers! I hope you find a solution that works best for you.

The house I grew up in, Chenango county NY, was mostly idle for some years after my mother died and while my father was being taken care of elsewhere less than 10 years ago. A sister lived 30-40 minutes drive away. We did two things to alert to heating (hydronic) failure.

There were close—by neighbors that could see front windows that faced the road so we got a device that turned on a light if the temp fell below a set point and plugged in a table luminaire with a red lamp in it in front of a window. These devices go back more than 50 years. I am sure that some version is still available.

There was still copper phone line to the house and we got a simple dialer-based system that could detect both temperature excursions and water. I pulled water detectors down to the basement floor so we could leave the temperature sensors on the ground level floor since they would not be very useful down below. I know that if there is not hard phone service it might be kind of expensive to maintain this kind of system with a cellular connection. On the other hand, there are still some areas that have lousy cell service so people still have copper. I am sorry that I don't remember the name of that or how much it cost.

In another application, where I did not need remote signaling, I used something called a Watersiren. It did have the option of a contact closure to implement remote signaling. It worked well as a local alarm and did not cost that much. Thinking about it now, he still had hot start boiler and monitering boiler temp would give an earlier warning. On the other hand, that would be useless if a circulator pump failed.

What about the water heater? do you drain and isolate it or do you pump 40-50 gallons of antifreeze into it?