Frozen pipe question

olsdjemfhuye21

Hi guys,

New here, hope this is the right forum. I do a lot of winter business travel necessitating leaving the house empty. Leave the thermostat @ 60. Last winter with sub zero temps, pipes froze resulting in extensive damage. The culprit was a gap in the exterior wall framing which allowed cold air in. Foamed the cavity. Was advised to drain all the pipes, turn the heat up, and turn off the H2O oil fired water heater, As a test, I did this over the summer (recently), and when I returned and turned on the H2O heater, the rapid heating caused the pressure relief valve to blow, flooding the basement and creating yet another mess.

I have 2 questions here. The first is what's the best way to leave a home in the winter, and the other specifically is, if I drain the pipes, turn off the H2O heater, what's the best way to safely heat the water back up so it doesn't expand so quickly and blow the valve?

Thanks, I appreciate it!

JUGHNE

At a minimum I would shut off the water supply to the house and drain the pipes to get the pressure out. At least then a freeze up broken pipe would not flood the house.

After you start the WH firing, you could open a hot water faucet to a small stream to alleviate the rapid pressure build up.

Jamie Hall

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.

Big Ed_4

You should have a thermal expansion tank on you domestic water system .It needs to be recharged or replaced . The tank takes uptake the expansion of the heated water ….

To be 100% winterized remove all water.

olsdjemfhuye21

Thank you all. Perhaps I'm overthinking this, but coming home over the winter to water flooding down the ceiling stays with you. My instinct is to turn the H2O off, turn the WH off, leave the heat on. When the expansion valve was replaced, I was told that leaving everything on and letting the upstairs faucet drip "Should" be sufficient. The WH recently had the control panel replaced with the digital Carlin Pro X, so maybe they need to adjust something on that? I didn't see an expansion tank anywhere, where would that be located and what does it look like?

Also, if I turn the H2O off at the main, do I leave the feeds from the WH open or closed?

Jamie Hall

Whether your house needs an expansion tank on the hot water system depends on whether there are any check or pressure reducing valves. If there are, then it either has to have an expansion tank on the hot water or, if you are on a private well, the expansion tank for pump control will take the expansion.

It is a common myth that leaving a faucet or something to drip will keep the pipe leading to it from freezing. The myth is false. Plain and simple.

Should you leave the heat on with the water off? Well… that depends.

If it is steam or hot water, and the boiler has a functioning low water cutoff, maybe — but if the water level gets low, you have no heat. If it is steam, the basement rarely freezes — even in very cold weather — so if someone looks at the house now and then, it's probably OK. If it's hot water heat, there is water throughout which, unless you are using antifreeze, will freeze, which you do not want. If there is an automatic water feeder on the boiler… at least the water to the boiler has to be left on.

If you have hot air heat, that isn't a problem, so everything can — and should — be drained. If you drain — or rather when you drain — everything — all faucets and valves — should be opened, and left open.

As I said, earlier, never attempt to start a water heater or a hot water boiler unless the system is completely filled with water. This means, among other things, that you can't do it until the house is above freezing.

A steam system is another matter. So long as you can get water to the boiler, a steam system can be started when the house is below freezing even with the basement somewhat below freezing, but it has to be done carefully. Can't just flip the switch. (I've done it, more than once), although it is iffish if the boiler is only just barely big enough for the system. (And before someone jumps on me, this is one situation where that "pickup" factor really is needed).

DCContrarian

 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.

Mad Dog_2

It always kills me how most people have that UNCONTROLLABLE urge to set the T Stat too low when they travel...for what??? What did you save? Leave it where you leave it in cold 🥶 weather and you'll avoid this. Mad Dog 🐕

Intplm.

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.

Jamie Hall

Oh I forgot that, @Intplm. . Sorry. Yes, antifreeze in all the traps — and don't forget the toilets. Use RV antifreeze. It's cheap. Better yet, it's non-toxic or at least relatively low toxicity.

olsdjemfhuye21

Thanks to all, this is really helpful.

Jamie, could you explain this, please? My system is forced air, oil fired boiler.

As I said, earlier, never attempt to start a water heater or a hot water boiler unless the system is completely filled with water. This means, among other things, that you can't do it until the house is above freezing.

Jamie Hall

Forced air with a boiler? OK, you probably have coils in the hot water ducting which are heated by the boiler? Or is it a direct oil fired furnace on the hot air system? They both exist — and it makes a huge difference.

If the heating system has hot water coils in the ducting, they need to be treated like any other hot water heat system so far as startup when cold is concerned: you can't do it if the house is below freezing, unless the hot water heating system has glycol antifreeze in it (some do). And, if they have been drained, the system must be full of water and purged before attempting to start it.

On the other hand, if your heating system is a direct oil fired furnace for the hot air, you can start that any time you like — no special precautions either for shutdown or startup.

Now as to the domestic hot water heater — which, I believe you mentioned is oil fired — that is somewhat similar, in that you cannot start it if the house is below freezing — and it can't have antifreeze, of course. The hot water heater must be full of water before the burner is started — and the only way to ensure that is to go to every hot water tap in the house and run the hot water until you get no air.

olsdjemfhuye21

oh, my..let me clarify. Oil forced air heat, oil WH. Well water. If I leave the heat on, drain the pipes… Turn off WH, including leads. Then, I close taps, turn main H2O on, turn WH on? I'm assuming the house will be above freezing, and the WH full. What's the order for turning things on, esp to avoid blowing the WH pressure relief valve again?

Intplm.

The water heater will probably be the last thing you turn on.

Run the hot water side of a faucet for a couple of minutes until the air is out. That way you know the water heater is full. Then turn the power on to the water heater. You do it this way so the water heater is full with the heating elements inside the water fully submerged.

I don't trip the relief valve because oftentimes the thing doesn't reset from a simple hand trip.

nelsonnucla

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.

mattmia2

https://forum.heatinghelp.com/discussion/comment/1805222#Comment_1805222

The shop vac is probably actually better for producing enough flow through the pipes to get the water out than most common homeowner sized compressors.

olsdjemfhuye21

OK, so to start everything up, I open the main water, I open the two feeds from the WH, I leave a hot water faucet open to get the air out close the others, then I turn the WH on? And then I open a hot faucet to prevent the pressure relief valve from blowing?

And to shut everything down, I turn off the water main, turn off thre feeds to/from the WH, open all the faucets? Do I have the order here correct?

Again, thanks so much, this is really helpful.

mattmia2

You either need to get rid of whatever is a check valve in the system or add an expansion tank if heating the water in the water heater is blowing off the relief valve. The problem doesn't go away with a smaller delta t, it is just not as noticeable.

Zman

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.

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1805270#Comment_1805270

There's more to it than turning the water off and opening the taps. But if you blow out the water with compressed air and put RV antifreeze in all the traps, including appliances, it's pretty reliable. I've probably done it 100 times.

Zman

https://forum.heatinghelp.com/discussion/comment/1805274#Comment_1805274

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.

SlamDunk

I have a home in the NC foothills that is unoccupied until we need to get away.

I installed a shut off valve inside the foundation wall, and wrapped 12' of heat tape around the supply pipe from the penetration up and wrapped that portion of pipe with fiberglass insulation. This is a vertical to horizontal run that cant be drained..

I close this valve, drain the hot and cold water lines from basement (we have a sink in the basement) while a faucet upstairs is open to brake the vacuum.

Add RV anti freeze to toilet bowl and tank and turn off electric hot water heater and furnace. Done in Ten minutes.

Power is rarely lost for more than six hours and we only have 1 to 3 weeks below freezing. It is too expensive to keep this house heated all winter. No internet for remote control of furnace when needed.

The one problem so far is cracks in the sheet rock. We can live with that.

wxfield2

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.

Electbc

On another note, I know someone who was just on vacation in the summertime and came home to water damage. The plastic hose to the icemaker cracked and caused extensive damage. Don't rule out RO filter tubing, washing machine hoses, dishwasher hoses and Toilet and faucet braided hoses. I had a leak on my toilet on the plastic nut meeting the shutoff valve, hard water corroded the fitting.

There are plenty of leak detectors out there, local alarms, home monitoring and flow monitors with automatic shutoffs. There will always be a leak where there is no sensor though.

I have simply safe monitoring and they failed to call us in the middle of the night with a leak alarm, our phones are on silent mode at night, put any monitoring service on a priority contact. Murphys Law.

bio_guy

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.

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1806357#Comment_1806357

I did that once, but it took forever to get the taste of the antifreeze out of the water in the spring.

DCContrarian

https://forum.heatinghelp.com/discussion/comment/1806357#Comment_1806357

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

SlamDunk

I leave my HW heater full.