Min. Outdoor Temp w/o Tank Heaters?

[masanders]

Our travel trailer is a 2015 Flagstaff 27RLWS. The tank heater switch plate has a blank so I assume it is not equipped with tank heaters. The bottom of the trailer is covered with corrugated plastic sheeting screwed to the frame which should provide some insulation for the fresh, gray, and black tanks. Does anyone have first-hand experience at what low temperature the tanks will begin to freeze?

[BigH]

They will freeze at 32 degrees Fahrenheit.

I know, not what you meant...
If you are worried about the low tonight of 30ish in the twin cities I wouldn't be too freaked out about because it will not be cold enough long enough to bring the temperature down on all that mass but I would get that winterization done before the low 20's next week.

[pilotpip]

If you're worried about an evening or two below freezing, disconnect the fresh water line if you're on a full hook up. Fill the fresh water tank with some water to use. Open the cabinets with plumbing in them so heat can circulate better. Should be fine.

[dward51]

Also a lot of trailers with the coroplast underbelly have a heat duct from the furnace that feeds the underbelly area (the corrugated plastic you have is called coroplast). If you have access to the area where the furnace it located, check and see if yours has a flexible silver hose that runs into the floor and underbelly. That sort of changes the 32* equation, but you still have to deal with the freshwater line into the trailer and dump valves if they are not heated. I don't know if there is a way to say you are safe to "X" degrees with a "heated underbelly" as there are a lot of variables, but with the heat on in theory, you should be better than 32*.

[TitanMike]

If your daytime temps are well above freezing, the water tank(s) will have enough retained heat to keep them from freezing if the temp drops into the 20's at night. If you look at a typical day's temperature graph, warm temps during the day and the lowest temp is only achieved in the wee hours of the morning. As soon as the sun appears (even when cloudy) the temps start to rise. Only item that will usually freeze is the outside hose so fill the water tank, disconnect and drain hose, roll up and store in an area that will remain above freezing overnight.

If in a campground the faucets/hydrants are prone to freezing temporarily so make sure to fill water tank if you want to shower before noon

[AudiDudi]

We went about 5 days many years ago with temps in the teens and highs in upper 20's with no tank heaters. The only issue we had was the dump valves froze (but didn't spilt). The insulated water hose would occasionally freeze and I would put it in the bath tub with hot water to thaw.

[5picker]

As mentioned, things don't freeze solid the instant it gets to 32º.
It takes many hours and days to make that happen.
The few hours at 28º-30º won't do any harm as long as the temps come back up above freezing for the most part.

If you do have a heated underbelly, that will help even further provided of course, you run the furnace some.

There is no 'magic' number as to what temp you are good down to.
I've successfully stayed in my old 5th wheel (not equipped with tank heaters) for the better part of two weeks with temps near 28º at night and 45º to 50º during the day.

[NJKris]

Keeping my fingers crossed that I don't have to winterize until after Veteran's Day weekend, my last trip. So far here in NJ I've gotten down to 31 for a couple hours in the morning with no ill effects. Not hooked to anything but power right now, but plumbing is still wet.