GRHome - Frozen/clogged septic lines

And how to clear them? Trying to avoid calling a plumber, but I'm out of ideas.

In my house, we have three main drain lines that run from the house to the septic system: 1st is the kitchen and shower, second is the toilets, and third is the washer/dryer, HRV, and furnace. 1 & 2 working normally, but after spending a week in the hospital with our newborn at -20 it appears the 3rd drain has frozen somewhere. I plugged the heat trace in once we realized it was clogged/frozen and normally that fixes it but not this time.

I've pumped hot water in to the drain till it almost overflowed multiple times. I've snaked it and it's clear through the trap. I've checked the clear out on the outside of the house (which is after all three drains meet) and things there appear to be normal.

What should I do next? Other than call a pumping/thawing company or buying a longer snake?

Bonfire?

I'd be awful inclined to rent a long snake for a day. I checked my local prices, $30 to rent a manual 75' snake for a day; $50 to rent an electric 75' snake.

Denatured alcohol? Gas line antifreeze type stuff?

What type of building are we looking at? A basement, crawl space? Your profile says Alaska and the whole -20 thing would back that up. Are you sure the heat to that line is working?

A couple of White Castle crave cases and some cheap beer. That should put some fire down the pipes.

you have a new baby, if you can afford it call the pro and be done. chances are they'll get it done quicker and cleaner than you could ever hope to do on your own, and you're not going to get cholera on your hands from dealing with a poo snake then go touch the baby.

Have you checked the inlet baffle on the tank itself?

IIRC this house is quite new? Saw the build thread, maybe call the contractor and ask a few questions about his thoughts on your problem?

I have had this happen.

Do you have a pump in the system? Mine has two holding tanks, poop and gray water. The gray water has a pump. When the water gets to a certain level, it kicks on and pumps uphill to a distribution box that splits the water between two sets of galleys. The line from the pump, the distribution box and the galleys aren't very deep.

During the first winter in my house, the system froze up. It was 12 degrees. I had to jackhammer down to the covers of the gray water tank and the distribution box. This sucks. I also broke one of the concrete covers and had to replace it.

Once I got them open, I ran a hot water hose into the d-box, downhill into the gray water tank, until it thawed out. The source of the problem was the fact that the long plastic pipe from the pump to the distribution box didn't have a small drain hole in it, so when the pump shut off, the pipe stayed full and froze. I drilled a small hole, probably 3/16", a few inches from the pump. Some water sprays out under pressure when the pump is on, but it falls back into the tank. When the pump shuts off, the remaining water in the pipe drains out through the hole with the help of gravity and prevents the pipe from freezing.

Also, my tank has two power lines running to it, one to power the pump and one to power an alarm that lets me know if the pump has failed and the water gets too high. Both are controlled by float switches. About six month into the house, the alarm went off. I discovered that the pump had been wired directly/improperly, bypassing the float switch and had been running constantly for six months until it burnt out. If you have your tank open, check your float to be sure the float switches are working properly. All you have to do is hook them with something and lift them up to see if the pump and alarm kick on.

The main system is working fine, thankfully. Toilets flush, showers go down, etc. it works even at -40.

House is post on pad construction, there is a crawl space underneath but all of the piping is encased in 12"+ of spray foam insulation. It is new construction, but the builder went out of business this summer. The heat tape on the pipe is buried under the foam too, but appears to be working at least at the plug end as it lights up when plugged in.

The clog/freeze is between the junction of the three drains before it heads to the septic system and the drain for the washer/dryer/furnace in the house.

I'm thinking more hot salty water and time with a longer snake, and if that doesn't work call the plumber.

Gravity sewer lines are always empty when installed and working correctly, and thus cannot freeze. You need to determine what the blockage is and prevent it from recurring. It is also kind of dubious that the blockage would be frozen so early in the year as sewer lines are typically very warm and it takes extended cold to penetrate that far down. Try a hot water jetter from the municipal cleanout at the street, or back from the tank if you are on septic.

In the past it's been ice from the slow constant water drip coming from the HRV and furnace. As far as early in the year, it's been below freezing at night since mid September, highs for the last couple weeks has been in the teens, and was -20 at night for the week we weren't home without any of the heaters plugged in.

We don't have a well or municipal sewer at the house, so hopefully the pumping/thawing guys can bring their own water.

Edit - the wife called, salt water (made with ice melt that we use outside) worked finally, the drain is free.

Sounds like you need some sort of timer setup on those heaters. On for X min every Y hours, or something like that. Back here in MD I would use a temp sensor but up there that would not be practical.

For what it's worth.

A heat tape that isn't touching is warming anything.

A red lit led at the top of the tape doesn't actually mean the heating coils downstream are doing anything.

Run into both of these problems with a friends place as he keeps trying to heat tape an external and lightly buried water line to a green house, as well a second external line under a porch. Neither have ever worked well in the winter and invariably freeze up.