Good point about the low pressure chemicals if the power goes out. But at least the ER won't freeze. I've seen the aftermath of that happening. I have a pure sine wave generator I can get the floor heat online quickly if I know the electric has gone off and is going to be off awhile. Luckily I live 2 blocks from my CW and if I'm out at home, its a good possibility its off at the CW too. We all know the N/O solenoid on weep will keep the HP hoses from freezing. My trough is insulated, SO maybe, just maybe, enough heat from the weep lines would keep the LP hoses from freezing! Like you, I've never experienced an outage long enough to pull out all the stops! But still like the wall heater for "Some" peace of mind!