Frozen lines and PEX

[JLMac]

I installed PEX plumbing a couple years ago. On a recent night temperatures dropped to -08 and the kitchen lines froze. The PEX manifold is in a heated laundry room, from which the kitchen sink lines go under an uninsulated and inaccessible room's floor, about a 6 foot run. It’s supposed to get even colder tonight. I was wondering could I simply close the two kitchen lines off at the manifold, but open and drain them at the kitchen sink, and thus empty them and protect from freezing? Is there a risk I’m not seeing? Would it even work?

 

[Geofd]

if the hot and cold are valved off cut in tees and low point drains open the faucet and drain them down

 

[JLMac]

if the hot and cold are valved off cut in tees and low point drains open the faucet and drain them down

Thanks for your reply. My PEX manifold is mounted on the wall almost head high. I put a ball valve about a foot beyond on every line. To get to the kitchen, the two hot and cold lines go down the wall to about floor level, and six feet horizontally through a space I can’t get into. They come out through the kitchen wall under the sink. So they drop, but raise up on the kitchen end. I can leave the sink cupboard doors open which ought to keep the mixer valve from freezing, but it is a horizontal run so I guess I can’t be sure it would drain completely. I know PEX isn’t as prone as copper to burst, but don’t know if this is too risky. Of course it’s apparently going to freeze anyway....

 

[Geofd]

Thanks for your reply. My PEX manifold is mounted on the wall almost head high. I put a ball valve about a foot beyond on every line. To get to the kitchen, the two hot and cold lines go down the wall to about floor level, and six feet horizontally through a space I can’t get into. They come out through the kitchen wall under the sink. So they drop, but raise up on the kitchen end. I can leave the sink cupboard doors open which ought to keep the mixer valve from freezing, but it is a horizontal run so I guess I can’t be sure it would drain completely. I know PEX isn’t as prone as copper to burst, but don’t know if this is too risky. Of course it’s apparently going to freeze anyway....

 

[Geofd]

if you had the drain valves after your branch valves you could blow out those lines in question with compressed air...or vaccum out the lines just for the cold snap....

 

[JLMac]

if you had the drain valves after your branch valves you could blow out those lines in question with compressed air...or vaccum out the lines just for the cold snap....

I’ve just been thinking over what you said originally, which was exactly right, a flaw in my original idea, and something I hadn’t considered. But I’ve also come to the same concluuusion...add a drain valve, and blow out the line. Or, it maybe I can reroute, lift or lower, one or the other ends of that run, put the drain valve on the low end, and gravity will do the rest. Either way, I believe you’ve told me exactly what I needed to hear to solve the problem. Again, thank you very much. I really appreciate your thoughtful response.

 

[Geofd]

that's why this forum is here...…….