[AT] antifreeze

[Kevin]

there can be a lot of antifreeze involved in these 
systems.   Though if this is your only source of heat that won't be needed >snip

If you are going to let the fire go out in winter, just turn the electric hot water heater back on and it will keep the from freezing. But cannot think of a reason to let it go out in freezing weather, easier to drain it than add antifreeze.
ironman
Kevin