North Point w/ enclosed unberbelly, frozen tank feed line

[bradjones1]

Brand new 2021 North Point 377RLBH owner here. Took delivery in Montana and am working my way south through some cold territory.


Similar in spirit to this post, but more related to in-camp operations: After a few days in camp successfully filling from city water and then working in dry camp mode with the water pump, we woke up this morning to no water pressure. Quick diagnosis showed the pump would run but could get no prime from the tank - my suspicion of course is that it is frozen. We keep the interior at around 65 F, and my understanding is some of this forced hot air should be ducted to the underbelly.



I can run from city water, but of course this is not a long-term solution in so far as if the water is not flowing, the feed line will freeze. Placing the water manifold in "power fill" mode flows no water, so I do not believe any lines are burst (ergo I would be flowing water "somewhere.")



This model has the enclosed underbelly so the only pex pipe I can visualize/work on from the basement storage is rather limited before it runs down the passenger side of the fifth wheel to the (inaccessible) tank. I do not have the "extreme weather" package which would have heat tape along this whole line - I think.



Questions:


1) Is the most likely culprit of the problem a frozen section of pipe? Anything else that would cause this?
2) Other than "waiting," any suggestions on thawing out a section of pipe that's likely beyond my reach under the coach and inside the enclosed underbelly?
3) There appear to be two sections of corrugated plastic on the underside, toward the rear of the coach, which could in theory be removed, but neither a T20 or T25 bit seem to fit the bolts, and I'm unsure if these are tank service points, anyway.


Thanks to everyone for all the amazing information I've gleaned so far during my lurking on the forum. I hope to one day help a clueless newbie out, myself!

[Jeffur]

Froze and split open the water pump suction line, split pump housing, pump can’t prime as it’s sucking air.

[Lake Huron]

The underbelly coroplast material isn't screwed on, unless they changed something in the last few years. They use some sort of "nail" with a large washed on the head. They don't pull out or unscrew either. I've tried. Tanking down the underbelly I don't think will get you anywhere. I'm pretty sure the fill line, vent line and line to/from the pump are all attached from the top side.
I'd disconnect the line from the tank to the pump and see if you can suck water out of it from the tank. If not, there's your issue. The pump should be fairly close to the furnace, so I doubt its frozen. Mine is less than 18" from the furnace and in the same open area as the furnace. I also doubt its frozen due to the fact you can use the city water connection. The pump and those valves are right close to each other. If they ain't froze, the pump shouldn't be either.

[Kahoneys]

I had the same problem a few years ago and found it to be one of the valves in the control panel was cracked and sucking air. Unfortunately I couldn't find a replacement valve anywhere so had to take it to a dealer.

[bradjones1]

Thank you to everyone for your replies - keep them coming for this very green newbie. A few of the responses seem to indicate the pump sucking air, however to "power fill" from city water pressure, I shouldn't require the pump at all, correct? (In fact the pump should be out of circuit?)

[bill3kirk]

Reference the coroplast. On my 2018 NP 377 it is fastened with 8 point star screws. However, after talking to a tech at a RV Shop, they use a number 2 square bit on the 8 point star screw. I used the same w/out any issues. I was able to easily remove them. I replaced them with #2 square stainless steel screws.

[Springhook]

Originally Posted by bill3kirk

Reference the coroplast. On my 2018 NP 377 it is fastened with 8 point star screws. However, after talking to a tech at a RV Shop, they use a number 2 square bit on the 8 point star screw. I used the same w/out any issues. I was able to easily remove them. I replaced them with #2 square stainless steel screws.

Did you screw into the original holes. I cannot imagine finding the original holes in the cross members.

[rkymntsno]

Your floorplan is almost the same as our 355mbqs. Your fridge is on a slide on the driver side. Jayco has a water line for the refrigerator exposed to the elements at the rear of the rig on the driver's side. When we took delivery, I insulated the line with foam pipe insulation along with the icemaker drain. Just grasping at straws here unless Northpoint did a better job of winterizing than the Eagle. There's no way that can pass winterized testing and pass or even say the rig can withstand freezing temperatures WITH AN EXPOSED WATER LINE!

[Radar57]

Could it be one of the diverter vales is frozen. It's a bit confusing but I think water comes from tank through the pump to the black valve then to the fixtures through the green valve when set for dry camping. That's if the NP is plumbed like the Pinnacle. Just a thought.

[bradjones1]

Originally Posted by Radar57

Could it be one of the diverter vales is frozen. It's a bit confusing but I think water comes from tank through the pump to the black valve then to the fixtures through the green valve when set for dry camping. That's if the NP is plumbed like the Pinnacle. Just a thought.

Thanks for the reply; no black valve on these models; it's a Nautilus P3 manifold.

[bradjones1]

Closing the loop (for now?) on this - feed line/supply line to/from the fresh tank stayed frozen even with a day of heat flowing into the basement - appears the line runs to a non-heated (but enclosed) area, so the cold really took hold! Thawed and appears to flow fine, now, with no leaks... but what an adventure.

[ALJO]

I put heat-tape on the pump suction-line, while the underbelly has R20 insulation.