We just bought our Heartland Landmark Savannah about 4 months so we haven't really been in the cold weather yet. But, since my husband has just retired 3 weeks ago we are planning a trip and will be in some cold places. It looks like we will need to but the remote thermometer also! But, where do you get access to the underbelly? Also, which thermometer did you buy on Amazon? Our 5th wheel has the residential fridge and in the manual they warn of the water line going to it will freeze even if you put on the heated tape. We really don't know what to do about that! We plan on calling Heartland next week about that! Thanks!
I have the remote thermometer about 18" to the rear of the drop frame, about 18" in from the off-door-side frame. That location is close to my Gray #2 and Black tank valves, and near the kitchen water lines.
A few months ago someone posted about
"zippered flex-mend trap flaps" that allow you to cut an opening in the coroplast and use the trap flap as a zippered access panel. I installed one where I have the thermometer and another where the frame drops, giving me access to the Gray #1 valve. They're designed for stationary mobile homes, so I'm not sure how well they'll do after getting a lot of road crud on the zipper. But if a gate valve freezes, opening that flap is a pretty easy way to get a hair dryer blowing on the gate valve.
Monitoring underbelly temps gets important in temps below 20 (F). Running the furnace will probably keep everything just fine down to around 20. Below that it can get dicey. When you get below zero, you really have to monitor or you can wake up without running water.
On the residential fridge (or any fridge with ice maker or water feed), as Jim said, you'll definitely need to evacuate the water from the feed line.
We've got a couple of user guides that may be helpful to you. Take a look at the
Residential Refrigerator Guide and the Water Systems Winter Usage Guide.