An elderly relative's toilet pipes are frozen under her mobile home. What is the best remedy to unfreeze toilet drain pipe? She recently returned from a week-long vacation. Interior thermostat was left at 60 degrees; faucets were NOT set to trickle. Some of the water pipes below trailer are wrapped with heat tape. Should toilet drainage pipe be wrapped with same?

Plumber will thaw out the toilet pipe under trailer tomorrow--apparently by using a torch. Plumber explained that water and sewage have been "moving sideways into the belly of the trailer and soaking insulation." What repairs should be performed, and how to prevent this freezing problem in future?

In an attempt to remedy the problem on her own, my relative poured anti-freeze into backed up water in the bathtub. (Someone told her to.) Comments? When water buildup remained the same, she moved/emptied the liquid down the kitchen sink. Plumber advised that she stop running any water down the drains.

Another question: is it advisable to leave hot and cold water trickling when my relative is out of town during the winter, during frigid temps while at home, and when electricity fails? Someone told her that this is the worst possible thing to do in a trailer, but I'm very skepticle of that advice.

Thank you for any help!

 

I'm no expert on mobile homes by any means, but the only water that should stand in a drain system that could possibly freeze should be in the traps only. Sounds like what has happened. She might want to put heat tapes on all traps under the mobile home, too.
If any drain line was stopped up, then water may have frozen there, also, but I wouldn't waste heat tape on them.
A toilet acts as its own trap inside the heated space, and should not freeze, as long as the home is warm enough.
Pouring anti-freeze (poisonous) down a frozen trap will only waste anti-freeze. Better off pouring hot boiling water down drains (except toilets) to thaw traps.
If that plumber says that he is going to thaw her pipes with a torch, fire him, and hire someone who knows what he's doing.
He should simply remove/replace any burst traps and lines, or thaw them with a hair dryer.
Leaving water dripping WILL help keep pipes from freezing.
Good Luck!