It's the 1st winter for the Mrs. & I fulltiming. I thought I had it all figuered out. Heat strip on the water supply hose wrapped in foam pipe insulaters. propane in the tank for the furnaces. Leaving the cupbaord doors & drawers open slightly over night to help airflow around pipes. Household fiberglass insulation around dump valves to prevent freezing down there.
Then it got down to 15 degrees here in Northern Georgia. BRRR.. Got up the next morn, started the coffee brewing, Then hit the showers. It didn't take long for my feet to be swiming in water. Didn't realize that the drain trap is below the floor level in a Classic MH. MH's don't have a belly pan to help the furnace keep the pipes thawed.
The 1st bright idea I had was to use a cup to scoop out the cold water out. After letting the water get hot, I ran all 6 gals. into the shower. Did'nt work. Drank coffe & pondered a while. Hmmm.
2nd idea worked so well, I had to share it. I let the hot water tank heat up again. Only this time I let the 6 gals. run down the kitchen drain into the holding tank. I figured the heat would rise into the trap to thaw it out. Darn, I was thinking about it so much I forgot that the dump valve was open & lost all that hot water.
Let it heat up another 6 gals. while I closed the dump valve. Let that hot water run down the kitchen sink into the grey tank now closed. The shower drain trap thawed in less than an hour enough to let the water in the shower flow out.
Now when it's going to get cold I pour a small amount of pink antifreeze into the drian. Just use about a coffee cup amount to fill the trap.