How essential are low-point drains?

[ReluctantTraveler]

I'm currently modifying my entry-level travel trailer for four-season camping.

The stock water lines run outside the camper. I've added heating pads (rated to -32 F) to the fresh and gray tanks, and am re-routing the water lines inside the camper where they'll be heated and won't freeze (I've got some thermometers stuffed in various places to test how cold the nooks and crannies get).

The one thing I've yet to add to the re-routed supply lines is a low-point drain. How essential are they to an RV water system?

We winterize by flushing our lines with compressed air, but even if we used anti-freeze, it seems like the whole system would be protected without them. I assume I'm missing something obvious.

 

[Buddha.]

I’ve wintered dozens of trailers and still haven’t figured out why low point drains exist.

 

[Alloy]

Done properly (very few are) low point drains prevent important componets (faucets/shower/ water pump) from freezing with out using air or antifreeze.

The same goes P trap with a clean out.

.

 

[Photomike]

You can go without but it is a lot easier if you have them. I never had to use air with my units just drained the tank, open the drain and taps and let it drain for an hour or so. Close the low point then I would pump some RV antifreeze and done. Never had a problem. I actually got into the habit of draining on the way home after a cold trip so by the time I got home it was ready for some RV antifreeze.

 

[billiebob]

If the system is built to drain completely thru low point drains compressed air and antifreeze are not needed.

 

[ReluctantTraveler]

I wonder is this is an American thing. All of the campers I’ve seen insist on compressed air or antifreeze for winterizing.
It definitely hits below 0 F here in the winter.

Given that I’m retrofitting the system, I’m also not confident I can get them to truly be the low point in the system. I needed to add some odd angles to route everything inside the camper.

 

[Photomike]

I wonder is this is an American thing. All of the campers I’ve seen insist on compressed air or antifreeze for winterizing.
It definitely hits below 0 F here in the winter.

Given that I’m retrofitting the system, I’m also not confident I can get them to truly be the low point in the system. I needed to add some odd angles to route everything inside the camper.

I am in Canada and camp in -40. In those temps I never use the inside tanks of my tcer or Class C for many reasons (Filling is a pain, constant heat, trying to dump).

I would winterize in October and fill in March.

In my van I have everything inside (water jug for fresh and grey and a portapotti that uses RV antifreeze). I just take fresh water out when I leave and dump grey, fresh and toilet when I get home with zero winterizing.

 

[simple]

In the NW our weather alternates between freezing an thawing all winter. It is really nice to fill the tank for non freeze trips and then open a low point valve after. Dump holding tanks of course and pour a little RV antifreeze in the P traps. Quick and easy. Having to blow out lines and hope to get antifreeze in them is an extra step I'd rather not repeat several times during the cold season.

 

[ReluctantTraveler]

Having to blow out lines and hope to get antifreeze in them is an extra step I'd rather not repeat several times during the cold season.

It's an either/or thing. If you use anti-freeze, you don't need to blow out the lines. There's a bypass on most commercial water pumps. You stick the end of the hose into a bucket of anti-freeze, turn on the pump, and open your taps until the lines fill.

I DO NOT do that. I attach my compressor to my city inlet, turn it on, and open the taps one by one until no water comes out.

I have a hunch my "what's the point of these" is from having a cheap entry-level trailer. I opened up my low-point drains until water stopped coming out, but when I ran my compressor through the lines, over a gallon of water still came out.

Every major manufacturer that I've seen recommends using either anti-freeze or compressed air to fully clear the lines. Maybe its just a CYA thing, but it also seems like my low-point drains weren't really at the lowest point.

ALL THAT SAID... I absolutely can see the value in adding them to my updated run of water lines as a just-in-case thing.

My new setup (with all of the supply lines inside the rig) should prevent freezing down into the 20s or high teens at least. But if I ever find myself in a situation where it gets colder than that or something in the system fails, having some drains I can use to get most of the water out of the lines, even if its not perfect, seems like a good thing.

Thanks for the perspectives, y'all!

 

[simple]

It's an either/or thing. If you use anti-freeze, you don't need to blow out the lines. There's a bypass on most commercial water pumps. You stick the end of the hose into a bucket of anti-freeze, turn on the pump, and open your taps until the lines fill.

I DO NOT do that. I attach my compressor to my city inlet, turn it on, and open the taps one by one until no water comes out.

I have a hunch my "what's the point of these" is from having a cheap entry-level trailer. I opened up my low-point drains until water stopped coming out, but when I ran my compressor through the lines, over a gallon of water still came out.

Every major manufacturer that I've seen recommends using either anti-freeze or compressed air to fully clear the lines. Maybe its just a CYA thing, but it also seems like my low-point drains weren't really at the lowest point.

ALL THAT SAID... I absolutely can see the value in adding them to my updated run of water lines as a just-in-case thing.

My new setup (with all of the supply lines inside the rig) should prevent freezing down into the 20s or high teens at least. But if I ever find myself in a situation where it gets colder than that or something in the system fails, having some drains I can use to get most of the water out of the lines, even if its not perfect, seems like a good thing.

Thanks for the perspectives, y'all!

I was referring to antifreeze in the P-trap which isn't part of your fresh water system.

 

[ReluctantTraveler]

I was referring to antifreeze in the P-trap which isn't part of your fresh water system.

Ah yes, sorry! If it wasn't clear, you still need anti-freeze for the p-traps/drains, even if you blow your supply lines clear with compressed air.

 

[Gravelette]

Late here, but... I'm kind of belt and suspenders. I blow out the system, then pump in some pink stuff. Blowing won't clear the pump and pumping won't clear the city water intake. I don't think low point drains would be of much use. There doesn't really seem to be a good way to use the water system in really cold weather unless you have a true 4 season trailer. It's not too much of an inconvenience to keep some jugs of water for flushing and hand washing.

 

[Alloy]

Late here, but... I'm kind of belt and suspenders. I blow out the system, then pump in some pink stuff. Blowing won't clear the pump and pumping won't clear the city water intake. I don't think low point drains would be of much use. There doesn't really seem to be a good way to use the water system in really cold weather unless you have a true 4 season trailer. It's not too much of an inconvenience to keep some jugs of water for flushing and hand washing.

We tried air on my buddies trailer and like you said water keeps running back into the pump.

I needed a system that would allow us to start up/shut down the sytem in freezing temperatures. All the lines (PEX) slope toward 4 ( 2 hot/2cold) low point drains. The pumps (there's a back up) are mounted with the motor vertical and 90 degree elbows on both sides facing down. Air blows water out of the pumps toward the low point drain. Nothing's frozen........yet