What freezing temp, was safe for water lines?

[Aceallenk]

We got lucky and managed to snag a privately owned seasonal with full hook-up at our favorite fishing spot just 45 miles from home. We already parked the trailer a week ago, and still haven't unwinterized the water due to some very cold days/nights, and even snow a few days ago. BUT we seem to be right at the fringe after Thursday where every day afterwards are very nice and beautifully warm but it looks like one night next week where the temp drops to -2c or 28.4F Question; what temp is it safe to keep water in the lines without really being to concerned about lines freezing and cracking open fittings or connectors.? Let me add I intend to only use my fresh water tank with the pump. I'll add that I'd keep the bathroom door open as well as the cupboard doors and maybe even leave the fan run all night to help circulate air around the trailer if that would be an asset and the furnace will have no problem keeping the temp inside at 21C or 72f. What have some of you people endured at what temperatures without encountering any problems with cracked lines? I'm not even concerned if the line gets a little slow at running cause it had a little ice, but I certainly don't want to have any cracked lines and have to stand on my head under a sink in a cupboard trying to repair a cracked elbow. Thanks in Advance !!

[backcountrycamp]

Personally I think anything below freezing and you're just taking a calculated risk. I can tell you what I've risked, but it doesn't mean your experience would be the same.

Water takes time to freeze, and campers take time to cool. If you have a modern unit with an insulated basement and PEX piping (sounds like you do) you have more safety margin than some.

Will the daytime temp and sunshine factor be enough to give you some heat? If so, a single overnight getting down to "just below freezing" isn't enough to cool the inside of the camper to freezing as well, AND get the water down to that point too. But if the daytime high is also below freezing that's a different story.

When I expect just one or two nights to be cold, but daytime highs to be at least 45F+ and some sun, I'll pour about a quarter bottle of RV antifreeze into the black and grey tanks to protect their valves (this is most effective if they're empty, or nearly so). I'll then let the pressure out of the water lines by opening every faucet (if there is any freeze expansion this also gives it some relief). If it's a VERY cold set of nights I may turn the furnace on and just set the thermostat to its lowest setting (45 for me). I've done this repeatedly over the years with no trouble, but YMMV and I definitely am not recommending it!

One thing I've found VERY helpful in my kit is a blow-out plug and air compressor. They're both cheap tools to keep in your camper at all times. If you're ever worried about a freeze period, it really only takes 5 minutes to blow the lines out, especially if you haven't fully de-winterized (including filling the hot water tank).

[Aceallenk]

Thanks Back Country, your right, and it's just not worth the risk of any water line freezing. It took about 2 minutes to make up a blow-out adapter last night and I'm even a bit surprised I never had one of those little benefits in the toolbox. and since I already have a 2nd small compressor sitting in the garage just collecting dust, it needs a new home in the trailer. Done deal... time to go camping and fishing and not worry about the weather and all the other crap constantly being repeated on the news 24/7...

[harley]

Easiest way is to shut off pump, open all taps including out shower . That will allow water to move in event of freeze and not crack any pipes. In the morning just close all . If you are really worried you could open low point drains also.

[dkwheeler]

Freezing temp 32F or 0C is when ice crystals start to form in water causing expansion thus can potentially start to cause damage especially with back flow valves and the pump. as suggested by others open taps and the water system drain valves (if exist). also as suggested pour some RV antifreeze into each water trap. Especially drain the holding tanks. a few more degrees of frost and you are rising anything that holds water.

[stetson]

Originally Posted by harley

Easiest way is to shut off pump, open all taps including out shower . That will allow water to move in event of freeze and not crack any pipes. In the morning just close all . .

Have camped in low to mid teens, with highs below freezing. Just used the on board water tanks, but did open taps. Most campers have ductwork with in belly storage which will give off some heat and keep water pipes thawed. More problematic is the valves for dumping.

[Kamper Dave]

COLD WEATHER CAMP @ 8ºF:

We have a Crossroads Cruiser 5th wheel RV CF31RE10 with the Upgraded Insulation Package and have never fractured a fitting or pipe. We pull into a Yellowstone NP campsite in April and leave in October. Camp is at 8,000 above sea level and we experience below freezing temperatures for weeks each spring and again each fall with a few extreme nighttime temperatures as low as 8º F.
• ELECTRIC HEATER with FURNACE: We employ an 800 watt Lasko Space Heater that can’t meet the full demand so the propane furnace has to cycle and with its heating ducts in the enclosed basement the tanks and under belly gate valves are protected from freezing.
• BASEMENT HEATER: I do place a temperature controlled 200 watt heater in the 5th wheel’s basement along with an indoor outdoor thermometer. The I/O thermometer always reads 40-45º and that is what it is set for.
• WATER HEATER: The water heater is left ON with all baseboard cabinets closed. The water heater is centrally located near most of the plumbing. The heat from the water heater keeps the interior kitchen, outside shower and bathroom plumbing from freezing.
• WATER SYSTEM FLOWS CONTINUOUSLY: The Campground demands that the water supply be kept at a small trickle to keep their entire system from freezing. (Camp is mountainside at 8,000’ ASL where no one is going to bury plumbing in solid rock.) So, we open the gray tank gate valve and turn the kitchen faucet on to a small trickle. This system worked successfully for 9 seasons.
• MOISTURE: Moisture control at these temperatures is a full time job. Any activity that produces steam must be vented. All rooftop vents are always cracked open.