Water heater bypass not working?

So I'm winterizing my trailer today and at first I don't know where the darn water heater bypass valve is. I finally locate it under an access panel which is under the mattress to the front queen bed. I proceed to turn the valve off so NO cold water should be hitting the water heater.

Now I go and turn the fresh water bypass valve on so it stops pumping from the fresh tank and now from my bottle of antifreeze.

Ok so I'm ready to pump antifreeze through the system - I place the hose into the bottle of antifreeze and turn the water pump on and WHOOSH the whole bottle is almost instantly sucked dry. I figured I would leave all of the faucets closed until the system had some pressure. Now I open the cold and hot water faucets rotating through the coach but I am only able to get a little (maybe half of the bottle of antifreeze) to come through the faucets. Where did the rest of this go? I proceed to use another bottle of antifreeze and again I notice that I am not getting as much out of the faucets as I should be.

So.. I go outside and take the plug out of the water heater tank and SPLASH - PINK******EVERYWHERE.

My question is going on if I have the bypass valve turned on that is supposedly cutting off all water to the hot water tank? Why am I getting the pink stuff in the hot water heater?

The only logical explanation that I can come up with is that the valve cutoff to the water heater tank is maybe not turned on all the way? I doubt this though because I really yanked on that sucker. Maybe I should double check this?

Another concern is maybe with out the hot water heater is plumbed. Cold water goes in the bottom and hot water comes out the top. The bypass cuts off the water supply before going into the bottom of the water heater tank but it SEEMS to route it up to the top and out through the hot water lines. Is it possible that when I turned on the hot water faucet it started sucking some of the antifreeze into the water heater tank and also some of the antifreeze through the hot water lines to the rest of the faucets? Should I have not turned on my hot water faucets while doing the antifreeze deal?

I do not remember having this issue at all on the last trailer that I owned.

Any answers would be greatly appreciated.

Seeking Advice

19 Replies

Old-Biscuit
Explorer III
Oct 30, 2013
Just remove the internals on check valve and then remove 'T' and install a Flair-it 3 way valve.
No new couplings, no cutting of PEX, nothing else needed
Bobbo
Explorer II
Oct 29, 2013
Old-Biscuit wrote:
mrkoje

Replace that upper 'T' with the 3 way valve

If the backcheck valve has to come out anyway, there is no need to double the work by taking out the "T" also. The shut off valve above will work beautifully.

Also, if you replace the "T" with a bypass valve, you are still going to have to put a coupler in where the backcheck valve was.
Old-Biscuit
Explorer III
Oct 29, 2013
mrkoje

Replace that upper 'T' with the 3 way valve
mrkoje
Explorer
Oct 29, 2013
Bobbo wrote:
My MH has a 1 valve system, but I have a PEX Flair It shutoff in a baggy zip tied to the backcheck valve, just waiting for the valve to fail. I will go to a 2 valve system.

I just picked up one of those at the local hardware store for nine dollars. The RV store wanted almost twenty for the same thing! All I need to do now is find the time to rework the plumbing. It shouldn't take long but if you seen the picture I posted on the 1st page -- it's a tight area to work in. I see my self cursing a bunch when I finally get to it.
Bobbo
Explorer II
Oct 28, 2013
My MH has a 1 valve system, but I have a PEX Flair It shutoff in a baggy zip tied to the backcheck valve, just waiting for the valve to fail. I will go to a 2 valve system.
wbwood
Explorer
Oct 28, 2013
My class c has a three valve system. Through me for a loop as our TT had the one valve. Also the TT was a heck of a lot easier to get to.
RoyB
Explorer II
Oct 23, 2013
I like my older three valve system just for the reasons discussed above...

There is no doubt using the three valves haha...

Roy Ken
mrkoje
Explorer
Oct 23, 2013
Old-Biscuit wrote:
YEP....1 valve system
With the handle on cold inlet (bottom valve) pointing up the valve would be in 'bypass' and the check valve (brass fitting on hot out) should stop any flow into WH

With handle pointing sideways....cold water would flow into WH and out top (hot)

Disconnect hot line and inspect that check valve...
Personally I would get rid of that check valve and install a shutoff valve. Hate those cheapo junk check valves. Prefer valves that I operate.

Something like this......

Or install another 3 way valve at that 'T' like this one...

Thanks for the imput. Tomorrow I'll go and remove the check valve and see if it's jacked up. If so... off to get a inline valve and be done with it.
Old-Biscuit
Explorer III
Oct 23, 2013
YEP....1 valve system
With the handle on cold inlet (bottom valve) pointing up the valve would be in 'bypass' and the check valve (brass fitting on hot out) should stop any flow into WH

With handle pointing sideways....cold water would flow into WH and out top (hot)

Disconnect hot line and inspect that check valve...
Personally I would get rid of that check valve and install a shutoff valve. Hate those cheapo junk check valves. Prefer valves that I operate.

Something like this......

Or install another 3 way valve at that 'T' like this one...
mrkoje
Explorer
Oct 23, 2013
Old-Biscuit wrote:
I'm confused by your first statement........

So I'm winterizing my trailer today and at first I don't know where the darn water heater bypass valveis. I finally locate it under an access panel which is under the mattress to the front queen bed. I proceed to turn the valve off so NO cold water should be hitting the water heater.

Turning the valve OFF would be closing it. So what valve did you close?

Do you have a 1 valve system on WH
Valve parallel..cold water goes into WH. Valve turned 90 degrees...cold water bypasses WH and 'check valve in HOT outet stops flow into WH

Do you have a 2 valve system on WH

Both valves have to be turned 90 degrees to bypass WH.

Sounds like the anti-freeze flowed backwards into WH thru HOT outlet.
Either bad check valve OR you have another valve that needs to be operated

It appears to me to be the single valve system. Here is a picture that I just took of it. It's hard to see but the valve is located on the bottom. The water heater is in a very inconvenient place to get to and the valve itself is almost inaccessible due to the small access panel the rats nest of wiring and plumbing going on.