Gravity fill hose freezing

[La Plata View]

So while doing some mid-winter maintenance I discovered a previous repair patch in the gravity fill line. I could see where a short section of pipe had been inserted in the line, RTV smeared around the patch and two hose clamps used to hold it all together.

Problem is the line is routed so there's a low spot between the fill port and where the line enters the fresh water tank (FWT). This allows water to collect here, freeze and damage the line. Taking apart the patch confirmed this as I had ice popsicles in the line. So simply re-patching the line won't correct this design defect problem. As I see it I have few options.

1. I could install a new fill port closer to the FWT to eliminate the low spot. But this involves lot of work and may not be possible due to the location of the FWT.

2. I could try to build in a low point drain to the patch. Thinking of drilling and tapping a plug into a short section of solid pipe that would bridge the flexible hose. Then add pulling this plug as part of my annual winterization.

3. Dump some RV antifreeze down the fill line during winterization. This would of course require plenty of flushing of the FWT in the spring.

I think option 2 is my best bet. But wanted suggestions from the community.

Thanks in advance.

 

[Thomas ho]

i would do the antifreeze. a cup or 2 in line ,flush in spring to tank with 5 gallons fresh h20 drain . refill with some water a decent splash of bleach , let sit , do this before you open up bypass valves . then turn on pump turn on all faucets , to purge anti freeze then let bleach water sit in lines for a day , then give it all a good clear water flush. mold likes to grow in water lines and makes your tap water smell like eggs. i have actually seen black come out of the tap.

 

[Reverse_snowbird]

I wouldn't do the antifreeze. It takes time to get rid of the taste.

Would it be possible to blow some compressed air through that port to get the water out of there? If you've drained the fresh water tank there shouldn't be any backflow to fill it again.

 

[NJKris]

For a big line like the gravity fill, a shop-vac hose on exhaust will blow any water out of that dip. Usually, a big line like that with plenty of room for expansion, I wouldn't think a little ice would hurt anything. It's narrower lines with little room for expansion that usually blow.


** or if you know where dip is, simply raise it up to drain it out when winterizeing, if you can get at it. Mine I can reach if I take out a kitchen drawer.


***also, i would at least have fresh water tank drain open so you don't overpressurize the line and cause damage if you use a high flow air purge, as from a shop vac.

 

[TitanMike]

Two thoughts:

First would be to see if it's possible to support the fill line so there are no low spots. One way if there aren't any places along the middle of the line, but you have a relatively straight shot, find a piece of ABS or PVD pipe with ID same as OD of fill line. Split and use as a stiffener, attached with lots of zip ties.

If that's not possible then splice a Tee into the line at the low point and just drain like at the other low point drains. Combination Tee's are available in most cases where you have the main line size same as line you are tapping and the new line size is smaller so you could use a small valve.

I would avoid the antifreeze route at all costs. NJKris' suggestion that you use a shop vac or blower to clear remaining water from the line is a good one that requires no other intervention.

 

[SimchaSabre]

X2+ on using air to blow out. Introducing antifreeze in the FW tank never ends well. I used a custom fitting to blow out ours, but I like the shop vac method better.

 

[TitanMike]

X2+ on using air to blow out. Introducing antifreeze in the FW tank never ends well. I used a custom fitting to blow out ours, but I like the shop vac method better.

Leaf blowers work too and may even be cleaner as they aren't used at other times to suck up dirt.

 

[shadows4]

Can you not just replace the whole fill line? If not what about raising the low spot with something under it? Pictures of what you are dealing with would help.

 

[Richy R]

The preferred method here.

Would d it be possible to blow some compressed air through that port to get the water out of there?

Well said. This is the path of least resistance.

 

[Qwkynuf]

So while doing some mid-winter maintenance I discovered a previous repair patch in the gravity fill line. I could see where a short section of pipe had been inserted in the line, RTV smeared around the patch and two hose clamps used to hold it all together.

Problem is the line is routed so there's a low spot between the fill port and where the line enters the fresh water tank (FWT). This allows water to collect here, freeze and damage the line. Taking apart the patch confirmed this as I had ice popsicles in the line. So simply re-patching the line won't correct this design defect problem. As I see it I have few options.

1. I could install a new fill port closer to the FWT to eliminate the low spot. But this involves lot of work and may not be possible due to the location of the FWT.

2. I could try to build in a low point drain to the patch. Thinking of drilling and tapping a plug into a short section of solid pipe that would bridge the flexible hose. Then add pulling this plug as part of my annual winterization.

3. Dump some RV antifreeze down the fill line during winterization. This would of course require plenty of flushing of the FWT in the spring.

I think option 2 is my best bet. But wanted suggestions from the community.

Thanks in advance.

If you are going to cut the hose to fix it, as in #2, can you remove enough material to shorten the hose and take the low point out of it?