Water line from fresh tank freezing?

2011 Cyclone 3800. I am currently parked in Colorado where the low temps have been in the single digits for the last few days. I'm using the fresh tank for water and the water line to the pump is freezing every night, I assume it is occurring at the tank outlet? I'm not positive because I haven't been able to access that area yet.

I bypassed the winterization valve yesterday and reconnected the supply directly to the pump, after applying heat to the pump area all day it worked great I had excellent water pressure with no air sputtering.

Late last night it froze again, I have the furnace running at 70 and a space heater situated between the two fresh water tanks, it dosent seem possible that is is getting cold enough at that location to freeze under those conditions. Any advise or knowledge on the subject would be greatly appreciated.


Well-known member
Hi forbesclan,

The problem may be the fresh tank drain which sticks out through the coroplast. There's a valve on that tube and there is water above the valve, exposed to outside air temps. In single digit weather, that water will freeze and the ice will wick up into the tee, blocking the feed line between tank and pump.

You could insulate the exposed portion, but in Colorado, that may not be enough. Another choice would be to put heat tape on the drain. A third choice would be to temporarily locate it above the coroplast. You may have to cut/retape the coroplast.


Founding Texas-West Chapter Leaders-Retired
I second Dan’s post, it’s probably the fresh tank drain. We wrap ours in pipe insulation and tuck it up into the underbelly, then seal the underbelly with duct tape.

Another source of freezing is where a water line is laying against the metal frame of the rig. Cold can transition through the metal frame and freeze the water in the pipe.

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Well-known member
From my experience, and it is vast with this particular issue, that will only solve half of the problem. You will also need to insulate the area below the UDC and the UDC itself. If it is like mine there is an area below the large hole at the bottom of the control panel that is open. You should be able to get insulation into that area from underneath. Then use insulation or several towels to insulate the entire area inside the control panel opening.

Insulating the drain hose will help keep that from freezing but cold air still gets into the panel area from below and through the UDC cover door as there is no insulation behind the panel. The pump is directly behind that panel and will freeze up even with the drain covered if it gets cold enough outside. 10-15 F is about where I found that even with the drain covered the pump would freeze up. Once I figured out that I needed to keep that very cold air from coming up into the UDC freeze ups stopped.

I should add that if it freezes hard enough it will split a line or coupling in that area, then you have a larger problem.

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