One Sink won't drain--related to cold weather?

[Autumnstar723]

Trying to trouble shoot an issue that happened twice last winter and once again this winter. Starting with problem/resolution last year:

In January in Massachusetts, during a cold spell of temps below 20 degrees for several consecutive days, my kitchen sink stopped draining. (Bathrooms/laundry draining fine). Attempted drain-o type solutions, plunging, no avail. Called a plumber, ran a small snake the first day with no results. Came back the next day with a more powerful snake and sink drained. (Not sure if coincidence or not?)

Stopped again a few days later--hadn't used garbage disposal or put anything besides water down sink in that time. Definitely did nothing to re-clog a recently cleared drain.

Plumber came back, snake did nothing to help, poured acids down the drain which sat for several days. Sink then drained OK, problem didn't reoccur. (I do not recall what the weather was doing at that time.)

Sink drained fine until this January, where again in a spell of several days well below freezing, same drain stopped draining. Presuming it was related to cold, attempted pouring hot water into kitchen sink (no change), using space heater under sink/in cabinet where pipes led next/under kitchen in basement crawl space where drain led next--still no change. Left untreated for several days waiting for a good day to investigate a pipe on the roof which I believe may be a vent for this drain. Today, when temps have been above freezing for two consecutive days, the drain is running freely.

Not knowing a heck of a lot about plumbing, these are observations I have made, and I'm wondering if they could be correct--and if so, how can I prevent the issue from happening again?

Observations--
I have three metal pipes that stick up out of my roof--one alongside the kitchen sink, one in the center of my house (near my upstairs bathroom), and one on the side where a new addition was put on (near downstairs bathroom and laundry). Each of these seem to correlate to three branches of the drain pipe in my basement. Are these vents that aid in drainage?

Could cold weather cause ice to form or for a blockage to otherwise form in a vent? Could a blockage in one vent align with only one area of plumbing (here, the kitchen sink) becoming unable to drain?

If these first observations are accurate, how can I prevent this from happening? If it happens again, how can I treat it without waiting for the weather to improve?

Thank you thank you thank you for any advice or information with this issue!

(In the attached image, the pipe in question is the lower right. You can see from the snow around it, this pipe does not get much--if any--direct sunlight in the winter. The window below is the kitchen window, and the sink is directly below this window.)

 

[Matt30]

Frost hoar can choke off vents, but your vent size penetrating the roof is sufficient. I don't like the fact that they decreased the size with an extension, but in reality that probably won't hurt anything.

When the plumber got the drain flowing with the snake....did he actually clear a clog? Usually when you hit an obstruction, you can tell.

Kitchen sink drains generally run along an outside wall, is it possible the drain itself is freezing? There could be a section with a dip or back slope causing issues.how far does the drain run?

 

[Autumnstar723]

I was not home when he used the snake successfully, and I don't remember him elaborating on the details when I spoke with him later (he was a guy of few words--I just remember the gist that "it worked"). I'm suspicious that a clog isn't the problem (or at least not the only factor) because the drain stopped so soon after the first problem was resolved, then ran clean for a year, and the problem resurfaced during the same weather conditions (and resolved without any snaking or chemicals being used this time around).

As near I can tell, the drain runs under the sink, bends, then runs behind the wall (in the direction of the vent seen in the picture) and then down into the crawl space under the house. I am doubtful that a freeze here was the problem, only because I ran a space-heater in this area (about 8-10 feet from where the pipe enters the basement and slopes down) for about 4 hours last weekend with no results. The area never got *hot* but absolutely was well above freezing during that time.

I am unsure what exactly the pipes do within the wall between the bend under the sink and the journey into the basement--but I also ran the space heater inside the lazy susan cabinet in front of this wall space--again heating to well above freezing, at least--before trying it in the basement. I also avoided using our woodstove over the last several days and kept the thermostat in the house running warm over a few days just in case that could help heat the house in more places than the stove in the livingroom was capable of doing.

Hope that clears things up?

 

[frodo]

i am thinking the area I have circled is freezing. the arm, most likely has insulation on the interior wall side.

but not between the arm and the siding. my opinion