If you’re a member of the RV tankless water heater club, congratulations! You now get to enjoy unlimited hot water on demand for showering, cooking, rinsing the dog, and drinking green tea. 

But what’s the protocol for winterizing an RV instant water heater? Contrary to what you’ve been told, there isn’t a one-size-fits-all answer. Some on-demand water heaters should be drained and left dry; others should be pumped full of liquid antifreeze. The Golden Rule is to check your Owner’s Manual!

However, for your convenience, I’ve compiled a list of common RV tankless water heaters with some instructions and tips on winterization. I’m not going to waste ink by copy-and-pasting the Owner’s Manual, so whenever possible, I’ll point you in that direction.