Winterizing question about FW tank line to water pump.

[Mookie58]

I am doing my first winterization. I opened the low point drains and drained the hot and cold lines the best I could that way, and then followed up with compressed air via the city water connection to push any remaining water out each hot and cold faucet setting as well as the toilet. I also blew out the Showermise line in the shower. I then turned the supply valve at the water pump to the setting that uses the antifreeze suction port located on the outside of the trailer. I plan to pump and fill the water lines with antifreeze in a day or two. I'll also fill the Showermiser line and allow antifreeze to fill the low point drain lines (pumping a little more antifreeze after in to make up for anything lost through the low point drains).


As I was changing the water pump supply valve position I wondered how I ensure the supply line from the FW tank to the water pump is either cleared with air or filled with antifreeze. Did I miss a step somewhere? Thanks for any help offered!

 

[D W]

Drain the FW tank. That will empty the line to the water pump. Don't forget to empty the sediment bowl if equipped. Once you switch to winterization mode the pink stuff will go through the pump.

 

[Mookie58]

Thanks for the comment DW. I suppose you could assume that the supply line from the FW tank must go "uphill" to the water pump because of the location of the tank relative to the pump. Therefore, gravity would drain it if there was no suction on the line. I did drain the FW tank prior to starting the process.

 

[Ejs4029]

Don't forget to winterize the outdoor shower

 

[Mookie58]

Outdoor shower - check.

 

[jimmoore13]

IMPORTANT STEP OFTEN OVERLOOKED

On the intake side of the pump, there is a strainer...image.

While you are in the pump cabinet, where the suction hose for winterizing and the pump live, you'll see the strainer.
You MUST remove the cap from the strainer and allow it to drain. This takes a few seconds. Bring a small towel to absorb the water that dumps out. WATER IN THE CUP IS VERY UNLIKELY TO DRAIN BACK INTO THE FRESHWATER TANK. Furthermore, the check valve on the pump will significantly inhibit water draining back into the fresh tank. Remove the cap, clean the filter screen, and while it's open, the water in the line will drain back into the tank. Once drained, replace the screen filter and cap.

If you winterize with RV antifreeze, I believe antifreeze will fill the filter housing. I don't use antifreeze in my freshwater plumbing, so I'm not 100% sure. I winterize with air.

Depending on your fresh tank drain:
a) 1 1/2" gate valve for a quick dump;
b or, roughly 3/8" quarter-turn ball valve that allows water to piddle out of the tank for a long time;
it's wise to leave the fresh tank drain open over the winter. But the large gate valve dump can allow vermin into your fresh tank, so leave it open for about 24 to 48 hours to thoroughly drain and stuff a stainless steel scrubber into the gate valve to allow water to pass but keep out rodents and insects looking for water. Then close it.
I have the old-style quarter-turn ball valve, and I leave mine open all winter, because even a tiny amount of water draining into that valve could freeze and crack the valve. No fun in the spring. The same is true of your low point drains. If you leave them open, residual moisture in your system can't collect in the shutoff valves/caps and crack the plumbing.

 

[Mookie58]

Jim - thanks for the tip on the pump strainer. I do know where it's located and it should be flushed with antifreeze when I use the antifreeze port to fill the system. Checking the strainer is a good idea anyway. I have the larger 1.5" gate dump valve on the FW tank. I have read where many people leave this open all winter but I am nervous about it.