Fresh Water Tank Freezing

beemerphile1 wrote:
It will take a long, long time to freeze the tank. The bigger (and more immediate) issue is freezing the valves and lines. Have a dump valve break and freeze and it could be costly.

This is the real issue. The line to the filter and pump will be solid long before the main tank begins to freeze. If the line is a flex line or PEX, that will not be an issue, but any elbows, t's, the pump body and filter bowls will split because they cannot expand with the ice. I'd suggest a heat light or a drop light with as large an incandescent bulb as you can find will give a good start at protecting these areas. Place in the wet bay near critical pieces. Of course there's always a danger of fire, but careful placement and monitoring will solve that problem. Heat lamps and rough service bulbs can still be had at wattages that get around the ridiculous Government edicts but still supply enough heat to work well. I've permanently mounted sockets at places that will not cause a potential fire problem. A remote temp sensor from Walmart is less then $10 and will let you know if temps start to get too low without having to open the doors and let the heat out.