Originally Posted by Trickdog
I have a 2008 ForestRiver Georgetown 373. What does the ARTIC PAC switch do? Its gonna get down to the 20's tonight? I assume it warms the fresh, grey and black tanks? Attachment 198059
Usually only the black and gray tanks, but possibly yours has the FW tank too. On our Class C at least you can see the heater pad wrapped over the tanks underneath so have a look.
Be sure to run the furnace not a space heater because (hopefully on your model...) the furnace heats the under-floor water compartment including the pump and FW tank and most of the water lines. I should say keeps them from freezing, maybe 40-45 degrees. Do you know if your has a duct running to the under-floor area? You may be able to see from inside the furnace compartment if you can get to that.
A short hit of 20 won't freeze a tank of water by any means, but it's cold enough to freeze any external parts which could include: external sink or shower, FW fill port, low point drains hot and cold (which do hold water to the bottom), FW tank drain line if it protrudes underneath and if it holds any water when closed.
If in doubt, drain the FW tank and lines opening the hot and cold low point drains and opening all the faucets, shower handles, toilet flush and sprayer, and release the FW fill valve behind the filter screen. You can always refill tomorrow, hopefully. Good luck.