Winterizing My RV Water System

Today’s goal was to winterize my RV water system. I decided to walk over to Safeway for a few things, then come back to get the car so I could drive across town to Canadian Tire to get RV plumbing antifreeze.

On the way to Safeway, while standing at the light to cross Scenic Drive, I happened to glance south and jumped back in shock. Look at what I could see:

Surely that Canadian Tire is a mirage...

WHAT?! There’s a Canadian Tire directly across the road from my apartment complex?! Getting there is a bit roundabout, but it still only took about 10 minutes. What a find!

Anyway, I decided to forgo the groceries and get straight to winterizing. I had an absolutely painless shopping trip (!!! for CDN Tire!) and picked up:

-3 gallons of RV antifreeze (the instructions said I needed to pour 2 into the fresh water tank, so I figured I’d need extra for the P-traps)

-a funnel that I was thrilled to discover exists:

funnel with flexible spout

and a few other sundries not related to this post.

I got back to the rig and reread the instructions:

part of the winterizing instructions

The following winterizing instructions are taken from my 1997 Glendale Royal Classic owner’s manual and may not apply to your RV. Always check your own manual. RV tech Les Doll has a good RV winterization manual.

1) Drain your fresh water system


2) Clean out your holding tanks

Done. Not as well as I would have liked, especially for the black tank, but I would have needed to go to a FHU RV park to do the job properly.

3) Drain the water lines by opening the lowest outlet in the system (in my case, that’s the outdoor shower). Drain the water heater by opening water heater drain cock and pressure relief valve.

Done. And this is why you should occasionally flush your water heater with vinegar (something I did last spring in Blaine):

calcification on water heater drain cock

4) Remove the output line at the water pump…

I omitted this step because I couldn’t figure out why to do it. The RV has been winterized a few times before me and I could tell this step was never done.

It’s in this step that they mention water heater bypass kits. If your RV does not have one, you will have to completely fill the water heater with antifreeze. I have what is apparently an unusually large water heater, 10 gallons, so that’s a lot of antifreeze!

Thankfully, I also have a higher end rig:

water heater bypass diagram

water heater bypass valves

So before the next step, I made sure to turn the valves as directed to bypass the water heater.

6) Pour 2 gallons of antifreeze into the fresh water tank.


note to self, that's what two gallons of liquid in the fresh water tank looks like

7) Turn on water pump.


8 ) Open each faucet until a change of water colour is noted.

Done. And I knew I had all the water out of the lines because I got bright pink immediately at all faucets:

-Dressing room sink hot and cold
-Indoor shower hot and cold
-Outdoor shower hot and cold
-Kitchen sink hot and cold

antifreeze in the dressing room sink

9) Run the toilet…


10) While water system is pressurized, depress the city pressure inlet one way valve so that antifreeze flows outside the unit.


11) Get a little antifreeze into the water heater and through water heater drain cock.

Done (thank you flexible spout funnel).

12) Finally, be sure that antifreeze has circulated through the entire water system and that antifreeze is in all P-traps.

Done. I poured the last gallon of antifreeze down all the drains:

-kitchen sink x 2
-dressing room sink

Not counting draining the rig (most done at Jody and Gary’s), this was a very, very quick and easy process.

I ended up not blowing the water lines due to the lack of power outlet for running the compressor. The instructions really make this step out to be optional, so I feel okay with having skipped it. We shall see how the rig fares in the spring… Les feels that blowing out the lines isn’t a good idea.

Next project, figure out how to hook myself up to a power outlet 150′ away…

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  • I’m sure that you also wiped the antifreeze out of the sink, shower, etc. A lot of people don’t realize that it will stain if let to set there.

  • No, I didn’t, but thanks for the heads up. When I bought the rig, there was pink stuff in the sink and shower and it came out, so didn’t think twice to leave it like that. I’ll go mop it up right now!

  • You should mark with a sharpie where 2 gallons hits on your water tank. We did this with our pool pump this year past winter and wondered why we never had before. LOL.

    I don’t have an RV, but I love to read your posts on RV stuff! 🙂

  • […] I winterized my fresh water system last fall, a few people told me not to put any anti-freeze in the fresh water holding tank as it […]

  • […] I winterized my fresh water system last fall, a few people told me not to put any anti-freeze in the fresh water holding tank as it […]

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