dave are heated slabs designed in a way where they could be drained (blow it out with air pressure???) to prevent freeze damage...... Thinking about a long term power outage.... Owner needing to be away for a long period of time.....
Glycol is commonly run in this type of system at least in cold country; it is a nice way to heat even way out where I live - if you can insulate well enough not to have permafrost issues anyway. (Oil is much more efficient as a fuel source however using the Toyotomi 180-type water heaters- out in these parts)
