Pipes freezing with enclosed heated underbelly

[brendanf]

I’ve got a 2020 Kz connect 261rb, middle kitchen, rear bathroom with a sink, toilet, and shower.

We’ve been using the water pump and fresh tank since it’s freezing out, and a couple times today we’ve not been able to get water out of the rear sink or toilet (cold water only, hot will flow) The front sink works just fine with cold and hot water. It’s all in the enclosed/heated underbelly. Why would we get temporary loss of water at these two fixtures? Eventually it comes back. I don’t think it could be freezing underneath, furnace has been running pretty consistent. I don’t think it’s loss of pump power (ability) because the pump doesn’t even kick on during these times so it’s like theres no water pressure to the back of the camper and it doesn’t feel the need to re pressurize the system?

Kind of hard to explain, but hopefully that makes some sense

Edit - towards the end of the night the sink and toilet have cold water but the shower doesn’t - open the valve and nothing, no water comes out and the pump doesn’t kick on.

Everything has running water off the pump other than the cold water on the shower. Cold and hot water runs everywhere else, just not the shower. Before this the cold water was intermittently not running between shower, toilet, rear sink.


Any ideas? It’s only been in the 20s and the furnace has been running, so idk how half the trailer could freeze? I feel like im missing something and that 20 degrees with a weather package and heated underbelly should not be freezing.

[David 70]

It sounds like you are getting partial freeze up of the lines intermittently. It may say it won't freeze in the brochures etc. but it's hard telling where the lines were located during manufacture. One or two may have a sag in them that gets close to the that allows them to get too close to the outside, bottom insulation etc. It's unusual that the cold freezes forst as usually the hot will freeze before the cold . An old moblie home I had the hot froze before the clod and both lines were side by side. The heating process does something to the water that causes the hot to freeze first.

[00 Buckshot]

I suspect your tanks,pump, and most of the lines are in the front of your RV and that area is heated but the lines going to the back bath are not heated.

[Reprobate]

If the water lines are not run in close proximity to the heater vents, they are susceptible to freezing, even with an enclosed bottom.
Do like the rest of us who use our RVs all year. Drop the bottom covering, investigate lines (you already know which ones freeze), and insulate them further.
Even though your RV may claim to have a heated underneath, there is so much going on in there that heat is not evenly distributed. It will be apparent when you drop the bottom.

[Concord]

I had this problem the first year with my current coach. Crawled underneath and found a 6x6 access hole left open from factory... I could see the pipes! Insulated cover over that and haven't had a problem since.

[Persistent]

Good advice posted above!

Be especially alert for leaks. Fittings and valves are especially sensitive to freezing.

[brendanf]

Originally Posted by Reprobate

If the water lines are not run in close proximity to the heater vents, they are susceptible to freezing, even with an enclosed bottom.
Do like the rest of us who use our RVs all year. Drop the bottom covering, investigate lines (you already know which ones freeze), and insulate them further.
Even though your RV may claim to have a heated underneath, there is so much going on in there that heat is not evenly distributed. It will be apparent when you drop the bottom.

I’ve seen good and bad things about this - is it typically a pretty quick/painless task to drop the bottom? I haven’t gone underneath it and inspected that much. I did notice this morning the rear insulation has sagged a little bit, which may allow for a draft to make its way through that area? I’m wondering if maybe next winter I don’t just skirt the entire thing instead. I’ve only had it out for 3 weeks and I’m new to it all, just staying in it during the week for work.

[Reprobate]

Skirting will help, but might not solve the freezing problem unless you have a heat source underneath.
Removing the bottom covering is not bad if it is coroplast (corrugated plastic) held on with self tapping screws. The first time I removed mine I cut it into thirds to make it more manageable. Taped the seams when re-installing.
Some coverings are more of a fabric. Some coroplast is installed with a steel pin nailer which are more difficult to remove.
I have removed a section of my coroplast many times over the years to address one problem or another.
Learning to live in your RV during freezing temps is definitely a learning experience, but after you get to know your particular RV, it will be second nature

[brendanf]

I would throw an electric heater underneath with the skirting for sure, seems a little silly to go through all that now so I’ll just use my furnace more than electric when it dips too far down below freezing.

I’ll save the removal down below until spring if at all possible, it is some sort of thin sheet metal/plastic like material. It has self tappers in the perimeter and 3 rows down the middle, so I’d like do the same and cut it into 3rds just in between intermediate supports. Surprised they don’t do this from the factory, a long thin piece of metal like that seems like a nightmare to handle.

[DutchmenSport]

I don't know how the KZ is configured, but the sales feature of my Montana stated "zero" degrees. And yes I tested it, and water does stay flowing at zero degrees ....... BUT, and this is the big "BUT!".... The furnace has to run and it has to run constantly. At those temperatures the furnace never shuts off. Running electric heat inside the coach area will cause the furnace to begin cycling on and off again, but the inside of the coach will still stay comfortable.

BUT... (and there is that big "BUT" again) ... when the furnace is off, no heat is going under the floor where all those pipes are. And when temps are zero degrees, it takes on a a few minutes for the cold to penetrate that 1/4 inch thick plastic chloroplast underbelly and cause pipes to frees .... very, very fast.

I had a Keystone Outback that claimed "Artic Barrier". And now my Montana claims "zero degrees." ... In both trailers, in order for the underbelly to keep from freezing, meant the furnace had to stay running .... and about 50% of the propane usage went to heat the underbelly..... Yes ... 50% of the heat went under the floor in 2 trailers.

So, if you are supplementing the heat inside the coach living area with electric heat ... there-in is probably the root cause of the freezing happening inconsistently. The basement area (under the floor) of the trailer has to have heat blowing under there, pretty much ... all the time in order to keep things from freezing up. And yes .... that takes an incredible amount of propane.

Start thawing things out by running your furnace non stop and get heat that heat under there.

Now, chances are the KZ does not use actual heat ducts under the floor blowing into that cavity of cold space. Chances are, all you have are water lines laying near the furnace heat ducts. If that is the case, then your camper was never intended to be used below freezing use, as much as it might have been advertised. You need to somehow pump more warm air under the floor to those troubled spots. About the only way to make that happen is to place a skirt around the trailer and get some heat under there until you thaw out. Meanwhile, blast your furnace. You may try pulling up one of the floor vent covers and bending up the duct, creating an opening so some air will actually blow under the floor. I did this with my first travel trailer and it worked pretty good.

[hamm2018]

Originally Posted by brendanf

I’ve got a 2020 Kz connect 261rb, middle kitchen, rear bathroom with a sink, toilet, and shower.

We’ve been using the water pump and fresh tank since it’s freezing out, and a couple times today we’ve not been able to get water out of the rear sink or toilet (cold water only, hot will flow) The front sink works just fine with cold and hot water. It’s all in the enclosed/heated underbelly. Why would we get temporary loss of water at these two fixtures? Eventually it comes back. I don’t think it could be freezing underneath, furnace has been running pretty consistent. I don’t think it’s loss of pump power (ability) because the pump doesn’t even kick on during these times so it’s like theres no water pressure to the back of the camper and it doesn’t feel the need to re pressurize the system?

Kind of hard to explain, but hopefully that makes some sense

Edit - towards the end of the night the sink and toilet have cold water but the shower doesn’t - open the valve and nothing, no water comes out and the pump doesn’t kick on.

Everything has running water off the pump other than the cold water on the shower. Cold and hot water runs everywhere else, just not the shower. Before this the cold water was intermittently not running between shower, toilet, rear sink.


Any ideas? It’s only been in the 20s and the furnace has been running, so idk how half the trailer could freeze? I feel like im missing something and that 20 degrees with a weather package and heated underbelly should not be freezing.

If you have low point drains on the rig, if these are left exposed, they can freeze. Once these freeze the ice will travel up the lines into the lines inside the RV, creating a blockage of some water to some areas while other areas keep working.
We experienced this in November 2019 in Chatanooga, Tn., when the temps got down to the low teens.

[Reprobate]

Originally Posted by hamm2018

If you have low point drains on the rig, if these are left exposed, they can freeze. Once these freeze the ice will travel up the lines into the lines inside the RV, creating a blockage of some water to some areas while other areas keep working.

We experienced this in November 2019 in Chatanooga, Tn., when the temps got down to the low teens.

Good point. We used to wrap them in towels or insulation held on with zip ties while we were stationary. Then we found some very well insulated draw string bags of various sizes that we put around the low point and fresh water drains. Works like a charm and is much easier.

[Tskadberg]

I found my rear toilet had a water line running from the sink so it could all be mounted on top of the floor. But for some odd reason the water line drops under the floor for 12 inches then comes up behind the toilet. Makes zero sense. I had this freeze on me as I had no idea it was done this way.

[Old-Biscuit]

leave cabinet doors open so warm air can circulate inside cabinets