We have sub-zero temps right now with wind chills. Our mobile home septic PVC pipes are frozen. We have a turbo-heater blowing hot air into the space below the house (which is on blocks) to try to defrost the line. It is about 8 feet from the line because to get it closer may be a fire hazard since the underside of the house has a layer of plastic stapled to it. It has been running for about 5 hours but the pipes are still frozen. We cannot use our bathrooms until it is defrosted, as we curently have water in the tubs-we ran the washing machine last night(not knowing the line was frozen) and when it drained it hit the frozen pipe and backed up into the bathtubs. I suggested heat tape on the line, but my husband thinks it will melt the pvc line. We live out on a farm and are not close to a city to run to a gas station to use the restrooms! Any ideas would help!!