because of freezing temps here in the Houston area in the last couple of days, I was informed by a neighbor, that there was water gushing out of the top of the watts b/flow preventor for my irrigation system.....I had wrapped all my pvc pipes for the separate zones and the b/flow preventor itself but not knowing a lot about the process of taking preventative mesaures against freezing, since we do not have that kind of situaton all the time, I did not close off the main supply valve to the b/flow preventor--AND for some reason, I had closed off the valve AFTER the b/flow prevtr....and I did not open any drain valves, as there are only the two ports which have little plastic caps on them....I finally closed off the main supply valve, put the valves which are before and after the b/flow preventor in an angle at 45 degrees and opened one of the slots with a screwdriver at an angle as per some instrs I found on the internet about these types of installations.....can u tell me if the b/flow preventor is possibly damaged since the water pressure was against it ??...also although the shut off valves on the zone lines were shut off and insulated, they are stuck now and cannot be opened....I am guessing wate got in each one and it is frozen, preventing the opening of them...Please Help me !

I see your solution I don't like it. If the water from the downspout freezes in the vertical line it will prevent your discharge line from letting water exit from the sump pump. That verticals line can freeze gradually if the downspout is only dripping water into the vehicle line. If you don't have a good flow of water it will freeze before it gets to the end of the line no matter what drop vertically there is. It's referred to as slow flow freeze here. Drip freeze, drip freeze, repeat. A larger diameter line as Brickeeye suggests makes the problem worse because in a larger diameter line there is less water vertically in the line which means the depth of water is less and the flow is wider which helps it freeze faster. A shallow puddle will freeze faster than a deep puddle. Heat trace the exit line from the sump or at least insulate it with insulating pipe tape. Many sewage lines to cisterns and septic beds have frozen this year because in the wisdom of our county they changed the code from 3" discharge to 4" from the dwelling to the septic bed or cistern We have a bit of experience with freezing here. Some places have frozen water this year that never froze in the history of the home. If you think it won't freeze again this year what brings you to that conclusion? This will be a long winter and late spring. I've lived here on the Great Lakes for 60 years and never felt the cold and constant wind like this winter. My heat trace line is good to minus 40C and it froze, 40C is where centigrade and Fahrenheit meets. -40C is -40F. Edit, do not put heat tracing on this line, of there isn't any water in the line it will melt the PVC or ABS. This post was edited by SouthernCanuck on Fri, Feb 28, 14 at 9:35

I doubt very seriously if the failure of the humidifier supply tube is a result of heat. First of all, let us consider the temperature of your incoming cold water supply. The mean average of the earths crust is 55degF (geothermal temperature of the crust). Soil is a rather poor insulator so the surface soil then cools proportional to the ambient air temperature. While the crust is 55degF the actual surface of the soil will freeze for a short depth which we define as the "frost depth". While the frost depth is the deepest point at which freezing commonly occurs it must be understood that from that depth the temperatures increase gradually from freezing temp(32degF) to the natural geothermal temp(55degF). Typically geothermal temp occurs at approximately twice the frost depth. In order to protect our water lines from freezing the codes require that we bury the line 6" below the frost line thus when the dirt is frozen to the frost depth the average temperate at the water line may be only slightly above freezing (34degF+). Fresh water reaches a maximum density of 231cu.in per gallon at 39degF. There is a very coplex formula to determine the rate of linear expansion but for the sake of illustration let us use the maximum here. When water is expanded from its maximum density of 39degF to the boiling point it expands by approximately 40:1 thus we could say the physical volume of a 40gal. water heater expands by one gallon. To put this in perspective consider that a 1/2" pipe has a volume of one gallon for each 98 linear feet. We must now keep in mind that water is not compressible therefore as the volume expands it must go somewhere. Normally the increase in volume is compensated by physically pushing some of the water back to the municipal main or to your well pump pressure tank however if we install a check valve in the line there is no place for the additional volume to go. In this case the excess volume would by necessity be relieved by discharging through the water heater Temperature & Pressure Relief Valve (T&P valve) BUT let us consider another potential problem here. Imagine for the moment that your T&P discharge line discharges out through the wall of your house. The discharge end of the line is then exposed to atmospheric temperature and in a worst case scenario the outside end of that line could freeze shut. At this point there would be no place for the additional volume to be released and it could result in blowing out fittings or valves or rupturing a pipe or the water heater vessel. Now keep in mind that the T&P valve is a spring loaded valve that is set to release when the pressure reaches 150psi and most likely the plastic line to your humidifier is failing slightly before the internal pressure is sufficient to release the T&P valve. On the other hand, if you did not have that plastic line there is a very strong likelyhood that the increased volume could be relieved by blowing out a compression fitting at a fixture angle stop, a pipe joint might fail or premature failure of Bibb Washers in your faucetts. The proper solution is to install an expansion tank on the water heater side of the check valve to absorb the increased volume. Installing an expansion tank is quite simple. You simply install a Tee on the cold water line with a male thread adapter on the Tee stub out, then screw the expansion tank onto the thread adapter.

FWIW: If you have had a pipe freeze (no water will come out) but it hasn't broken yet, then you have a damaged pipe in the wall that has reduced strength. I assume that you have copper liines and not PVC. PVC would have likely failed already. When a copper pipe freezes a plug forms on the interior of the pipe and expands the wall yielding the wall and weakening the pipe at this location. The next time it freezes (most likely at or near the same location) it expands and stretches the pipe some more. This pattern can repeat until the pipe wall breaks. You should have a contractor open the wall. He should be able to see the bulge in the pipe and therefore know just where to add the insulation. While the wall is open it is probably prudent to cut out the pbad section of pipe and replace it as well. My 0.02