How do I not blow up my city water connection check valve?

[rvhippo]

Jayco plumbed my city water connection line so that I will have trapped water against the valve after winterizing with antifreeze. Everything else looks like it should gravity drain.

Can I just press in the check valve and let the water drain out?

I have read here that I can blow up the valve if I do this.

Why would the valve be damaged by doing this?

Thanks in advance for any replies.

[dewey02]

rvhippo wrote:
What I don't understand is that one can send 40-50 psi of water or air through the valve during normal operation or winteriztion, but if I want to just release some trapped water, the valve can break so easily.

It has to do with DIRECTION!
When you are hooked up to city water or blowing compressed air through your lines you are sending that pressure INTO the system. The small O-ring is situated and designed to handle that pressure.

When you push in on the check valve while your lines are pressurized with antifreeze, you are exerting that pressure in the opposite direction and sending liquid OUT of the system. This can grab the O-ring and dislodge it, causing the check valve to no longer operate correctly.

I learned all this the hard way and had to disassemble the FW intake and reseat the O-ring, but it allowed me to understand how this all works.

Do as some others have said: first relieve the pressure in the system before you depress the check valve. Or get a manual pump and pump antifreeze through your City FW intake from the outside of the camper.

[Dave_H_M]

I am a pink stuff guy.

made a jumper hose to go from the outside shower to the connection for the black tank flusher. A little squirt and you are done.

[DutchmenSport]

Terryallan wrote:

DutchmenSport wrote:
...

... Why should I do pink, and air?

I end up having to use air anyway, because I blow out my black tank flusher, which is not part of the fresh water system.

Steps: 1. Drain all tanks, black and grey. 2. Pump the pink through the fresh water lines. 3. Blow the lines. Why? This pushes the pink stuff through the faucets and down the toilet and into the black and grey tank. This keeps the slide valves in the black and grey tanks wet all winter. 4. Blow out the black tank flusher.

I use to to "pink" only. But this forum got me turned-on to blowing. So now if I don't, I feel like I'm not doing it right. OK, the members of this forum "guilted" me into doing it! I admit it!

[georgelesley]

Terryallan wrote:

DutchmenSport wrote:
I run "pink stuff" through the water lines via the on-board pump. Then use an air compressor attached to the fresh water city inlet and pump air to push the pink out and it all goes in the holding tanks then. Using air via the city water inlet will definitely get rid of any trapped water. (This works for me). The entire process still only takes about 15 minutes.

On my old TT I used pink stuff, However on the new one, because I can't get to the inlet side of the pump, I just use air thru the city water. Never thought about doing both? Why should I do pink, and air?

Theoretically blowing alone should do the job. I like to pump pink after blowing the lines. Blowing it will take care of the inlet check valve for sure

[Terryallan]

DutchmenSport wrote:
I run "pink stuff" through the water lines via the on-board pump. Then use an air compressor attached to the fresh water city inlet and pump air to push the pink out and it all goes in the holding tanks then. Using air via the city water inlet will definitely get rid of any trapped water. (This works for me). The entire process still only takes about 15 minutes.

On my old TT I used pink stuff, However on the new one, because I can't get to the inlet side of the pump, I just use air thru the city water. Never thought about doing both? Why should I do pink, and air?

[DutchmenSport]

I run "pink stuff" through the water lines via the on-board pump. Then use an air compressor attached to the fresh water city inlet and pump air to push the pink out and it all goes in the holding tanks then. Using air via the city water inlet will definitely get rid of any trapped water. (This works for me). The entire process still only takes about 15 minutes.

[Bobbo]

After getting antifreeze absolutely EVERYWHERE else, turn off the pump, and open the kitchen cold water faucet. That will depressurize the water system. Leave it open as a vent, and go outside and depress the plunger on the shore water inlet. There is no pressure to blow the gaskets off, but the gravity flow of antifreeze from the kitchen faucet will flow antifreeze through and out of the check valve. Then, go back inside and turn off the kitchen faucet.

[csamayfield55x]

mayo30 wrote:
Well if you are worried about that then what about your black tank flush?

I was concerned about that exact thing last year. First year with a flush.

I got a blow out connector and just ran compressed air through both the city water side and the black tank flush. Seemed to work just fine, down to 0 last year and no breaks

Chris

[mayo30]

Well if you are worried about that then what about your black tank flush?

[djousma]

What I used to do was AFTER running antifreeze through the system, was to relieve the pressure, remove and reverse the steel screen, so that it would hold the valve in. then go back inside, and hit the pump button for a second, so that antifreeze got pushed out the inlet. then I just put the screen back in normally.

[Ozlander]

Most people don't drain it and never have a problem caused by freezing.

[SoundGuy]

rvhippo wrote:
What I don't understand is that one can send 40-50 psi of water or air through the valve during normal operation or winteriztion, but if I want to just release some trapped water, the valve can break so easily.

The check valve doesn't "break" ... rather excessive pressure causes the small rubber O ring inside to dislodge and the check valve can no longer seal properly. Simple solution - before pressing the check valve stem always relieve pressure in the system a bit by turning on one of your faucets for a few seconds, then close it again. There'll be sufficient pressure left in the system to push any unwanted water out of that city water inlet hose yet not enough to dislodge the O ring.

[rvhippo]

What I don't understand is that one can send 40-50 psi of water or air through the valve during normal operation or winteriztion, but if I want to just release some trapped water, the valve can break so easily.

[Dutch_12078]

Press the check valve in gently, and only far enough to let the water drain out. Mash on it, and there's a risk of unseating the o-ring seal. That's usually fixable, but it can be a pain to do.