I’m designing a PEX plumbing system for a small vacation cabin that barely gets used in the winter. I don’t want to drain and blow out the supply lines every time we close up and I’m pretty sure I don’t want to heat the place. Here’s what I’m thinking:
Jet Pump and pressure tank in the crawl space under the cabin housed in foam, leading to Pex wrapped in heat tape and jacketed with foam all the way up to the fixtures. Two small tankless electric water heaters, one for kitchen and bath sinks, one for the shower.
The winter close-up routine would be turning off the power to the pump, anti-freeze in all the traps, water heaters left on?
I’m wondering if it’s worth doing this or should I run it normal and keep the place heated to 35 the 3-4 months it freezes? The cabin is small and very well insulated.
Replies
IMNSHO it is not an either or, but a both.
You did not saw where this is so I have no idea of how cold it gets.
But if you have 35 "in the house" which would typicably be the center space, free air then places closer to the outside will be colder. And that includes under cabinets and in crawl spaces, and even more any place that there might be the slightest air leaks.
So I would not depend on 35 keeping the place from freezing. And even at that I would it would not take much of an interruption in power or a failure in the heater for the temp to drop much below freezing.
And if you heat tape it and have the heat off there risers and even the valves can freeze.
Here is what I would do.
Turn the heaters off and the pump. Install a drain valve that is easy to get to. Some have even used a ball and put a rod on the handle so it comes up inside such as in a closet or under the cabinet.
Then open the faucets and flush the toilet. That will emtpy the tank and most of the lines. And put antifreeze in the traps.
And keep the heat on low. In general the less cycling of the heat in the building the better long term for the building.
And you have enough water out of the system that if there is freezing then is will only do minimal damage, if any. My understanding that PEX can withstand some freezing.
William the Geezer, the sequel to Billy the Kid - Shoe
Should my drain valve be between the well head and the jet pump?
Do I need to do anything special with the pressure tank and pump?
Was not thinking about the pump being a jet.I use a jet for pump water out of a lake for irrigation. And I leave it in place and drain it from a drain tap in the bottom of the housing. Because Have discharge lines that go into the ground and back up I know that will hold water. So I do a blow down.And the drain valve uses one like on a radiator. Not very free flowing and easily clogged with a bug. So I am ready with a wire to clear it. That would not work in your case. I would use a full bore ball valve instead.Now I do not have a foot valve and I am only pumping the water up about 2-3'. But the pump has the jet on the pump and a built check valve.So I don't really have any place other then the tap on the bottom to drain it from.If yours has the remote jet then you can put in a T on the suction line and full size valve. But you want to use quality valves and connection because that is a suction point and the smallest leak with cause problems.But that will still leave some water standing in the centrifigal rotor chamber. Don't know if it will be enough to cause problems or not..
William the Geezer, the sequel to Billy the Kid - Shoe
LOL, get used to the idea of doing plumbing repairs regularly with that plan
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I would prefer copper over pex in this situation. Pex probably does survive occasional freezing better than copper. But in seasonal cottages around here (Ontario, Canada), you run copper supply like it's a waste line - that is, with a very slight slope, all downhill to a drain valve. Pex sags between supports; I could see a lot of water pooling in low spots.
After flushing RV anti-freeze though the toilet trap, make sure you add some to what water is left in the toilet tank, or use a wet vac to fully evacuate the tank.
Pressure tanks get drained. I have no experience with tankless water heaters; do they not drain completely? If not, and the power goes out, that's an expensive learning curve.
Regards,
Tim
The more I think about it I think I'm going to keep all the lines on interior walls and heat the place enough to keep everything from freezing. Here's my thinking:
1. If friends or family want to use the place I'm not sure I'd trust them to fill and empty the system on their own.
2. The cabin is small and in SE Wisconsin, a little bit of heat December through March will save me a lot of time and hassle.
3. I let the place freeze this past winter and my beers in the fridge exploded. My beers, my precious, precious beers! A soda exploded too and all our cleaning supplies froze and cracked their bottles. Big mess.
"3. I let the place freeze this past winter and my beers in the fridge exploded. My beers, my precious, precious beers! "One needs to keep their priorities in mind at all times.What is a little time to replace some cracked plumbing vs loosing some beer.BTW, even keeping it heated I would turn the pump off. Even without freezing, and it still can under worse case, and a leak in an unoccupied house can do LOTS of damage.I don't know if you saw ponytails story..
William the Geezer, the sequel to Billy the Kid - Shoe
what you need is a pump in the bottom of the well and no water in any pipe in the freezing zone.