Water Heater Bypass valve not by-passing

[BinaryBob]

I just winterized and had to buy way more anti-freeze than normal due to the above problem. 
No time to fix, as it's quickly getting down to the mid to low twenties here at night.
Not sure if it's hooked up wrong or the valve is bad.
Any ideas?
(De-winterizing will require a water tank drain and flush this go-around)

 

[AFChap]

i had TWO backflow-preventer valves at the rear of my water heater that were bad.  When the couplings were screwed into place, the internal fittings kept the backflow preventer valve OPEN. This allows the RV antifreeze to back-flow into the water heater. Winnebago claimed the valves were after-market (NOT), but even after a dealer "fixed" the problem it was still there. In the process they removed my electronic bypass valve which was not the problem at all.  I now have a manual bypass valve that still doesn't bypass because the black-flow prevener valve on the rear of the water heater cannot close. 

 

[BinaryBob]

Thanks.
I'll check this out.

 

[Top38]

If you have an air compressor, just blow out the system. No need for antifreeze other than the drain traps. It is easy to adapt an air line to the city water fill, adjust the air pressure to 30 or so psi and go to each facet one by one and open the H and C until all the water is pushed out. Before doing this, drain the hot water heater. Once you are just getting air from all the water sources, I go back tot he hot water tank and remove the drain plug again with the air still attached to ensure all the water is out. I live in MA, and my RV is stored outside so it's have seen many nights with temp's below 0! Been doing it this was for years. I always hated getting the antifreeze out of the system in the spring!

 

[Gary RV_Wizard]

Could be either the valve (simply not turning internally) or one of the check valves letting water backflow into the tank.  Winnebagos are notorious for heater check valve failure, that's where I would bet even though yous is almost new.

 

[John Canfield]

If you have an air compressor, just blow out the system. [...]

That's how they winterize some irrigation systems up north - blow the water out, cheap and effective.

 

[BinaryBob]

I've always used the pink stuff. Guess it's time for the compressor.
Can you provide more details on this method?
I'm guessing I need to cut a water hose to just a few inches long to attach the compressor to the water inlet?
Then drain the hot water tank and replace the plug to blow out? Is 30 psi enough to pressurize the hot water heater tank and blow the hot side lines?

Edit: I just realized there's an adapter to fit directly from the compressor to the water inlet. Need to find one.

 

[Rene T]

https://www.amazon.com/Camco-Brass-Connect-Aids-Removal-36143/dp/B002XL2IEA

Walmart has them and I would think hardware stores would also have them.

 

[kdbgoat]

I'm not a fan of the one Rene linked to. It has a small hole for air to pass through, as does many others of that type. Some even have a valve core and stem like a tire. Those are even worse. Try to find one with the larger hole. Some have a short piece of flexible hose made on it. Those generally have a larger size hole. My homemade one is similar to that kind. You don't need a lot of pressure, but the more volume you can move through your water system the better.

 

[Iron Horse-WO]

For what it's worth department......I too had this problem and finally figured out that you do the bypass setup and drain the hot water heater LAST, after you have winterized the system......have been doing it this way for years..........apparently the water in the tank prevents the antifreeze from entering......works for me......2007 Journey 36G.

 

[Gary RV_Wizard]

Iron Horse's no-bypass technique does keep antifreeze out of the heater tank as long as he doesn't open a hot water faucet anywhere. The problem is, no antifreeze reaches any hot water line or faucet, leaving them subject to freezing.  If the tank IS bypassed, then it doesn't make any difference whether it is drained first or last and no antifreeze gets into the tank anyway.

 

[Rene T]

I'm not a fan of the one Rene linked to. It has a small hole for air to pass through, as does many others of that type. Some even have a valve core and stem like a tire. Those are even worse. Try to find one with the larger hole. Some have a short piece of flexible hose made on it. Those generally have a larger size hole. My homemade one is similar to that kind. You don't need a lot of pressure, but the more volume you can move through your water system the better.

You're right. I didn't notice the small hole. I just Googled it and came up with that fitting. There are others out there. You could always just drill out the hole too.

 

[Gary RV_Wizard]

This is the one I own & like, but the basic size limit is the 1/4" chuck diameter of the quick-connect.

https://www.amazon.com/Winterize-Motorhome-Camper-Travel-Trailer/dp/B0056XBBB8/

 

[BinaryBob]

This is the one I own & like, but the basic size limit is the 1/4" chuck diameter of the quick-connect.

https://www.amazon.com/Winterize-Motorhome-Camper-Travel-Trailer/dp/B0056XBBB8/

I just ordered it.

Still wondering how the hot side blow out works with an empty water heater and a backflow preventer that's failed.

 

[Iron Horse-WO]

Listen carefully.....I  first put the system in the bypass mode......when I winterize my MH I open ALL faucets...HOT and COLD till the pink stuff comes out......meaning antifreeze is in the lines......THEN I drain the Hot Water Heater..................If you don't like my system keep doin' it your way...................