My house has a strange bit of plumbing. It's a house flipped by a contractor. It's plumbed for soft water, but there's no sewer near the closet where the plumbing is, and soft water units need a drain to flush water down during their regeneration cycle. The person who flipped this house solved this problem by installing the drain line (1/2" copper) upward to the roof, where there is then a pipe across the roof to a sewer vent.

We recently had a problem where the 1/2" vinyl pipe that connects to the drain pipe came loose. We think it was due to icing in the pipes across the roof, causing the joints to face the full house water pressure rather than just a small amount of pressure like one would expect on a drain.

We are already looking at ways to secure the junction more securely, but I was curious about trying to solve the icing problem. Besides the obvious insulation on the pipes, the next obvious solution would be to drain the pipe.

I can't drain the soft water out to the nearby ground because we have a tree out there, but is there a good way to perhaps drain the standing water out of the pipe?

(or, if I'm totally missing the obvious solution, I'm open to answers which provide a more correct way of plumbing things that doesn't involve hacking up my slab to put new sewer lines in or poisoning my tree with salt)

  • I take it the softener requires an AC outlet to run its controls to begin with, no? Jan 11, 2020 at 15:29
  • @ThreePhaseEel Yes, there's a standard 120V outlet nearby, of which one plug is currently unused.
    – Cort Ammon
    Jan 11, 2020 at 15:31

2 Answers 2


Use a drain pump kit

Since asking your water softener to try to drain up that far unaided is crazy, as they are gravity-draining appliances to begin with, this needs to be corrected properly, even outside of an icing climate. The good news is that since the water softener won't run without electric power anyway, we can safely use a drainage pump kit (laundry sink/washer drain kit) to motivate the wastewater from your softener to go uphill, without worrying about an overflow if the power goes out.


I would consider Self regulating heat tape. This will solve any icing issues. That sounds like a crazy solution I am surprised it was allowed but may not have been seen by the inspector. Insulation is also a plus but not knowing how the pipe is arranged on the roof insulation may cause problems. Some heat tapes that are not self regulating cannot be insulated . I like self regulating because only the areas that need the heat use power. Ok the whole thing uses a slight amount of power but as one section cools it warms up. I do have mine on a thermostat also so power is not wasted ehen the temps are above 30 (yes I know freezing is 32 but I have never frozen a pipe above 27 F)

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