Hot water tank bypass valves

[casefarmri]

Would like to know if anyone (07 Fleetwood Revolution LE) has some info on why this water heater has only one bypass valve. Winterizing after blowing out lines and draining with valve in bypass position?????, took 15-20 gal of anti freeze. Heard should only take 3-4 gallon. Is one bypass valve enough to block flow to water tank? One year newbie and trying to learn everything before cross country trip this summer.
Help Plz!

[Clay_L]

Some companies (Winnebago for one) use two check valves. Here is a drawing I made of my Winnebago setup. If you only have one check valve it will be in the hot water out line.

[MikeDavies]

We have a Coachmen Mirada 2004.The manual clearly shows 2 bypass valves and a check valve. It only has one bypass valve and a check valve.

[flapbreaker]

My money is on a bad check valve. Had to replace mine after trying to winterize this fall.

[Old-Biscuit]

If you have an Atwood XT Model you will not have check valve on hot out......you will have a 'mixing valve' as noted by 'MALEXANDER' and his post about HIS 2007 Bounder


If you call FW with your FW ID #, they will email all of your plumbing and electric diagrams.

800-322-8216

[jsr21]

Go here for good illustration

[casefarmri]

Tks tatest. That makes sense with the chk valve vs 3 bypass valves. I will chk to see if I can find chk valve.

[tatest]

My bypass has only one valve, on the water heater inlet. It reroutes what would go into the heater to the output side, and a check valve keeps water or antifreeze from entering the heater through the outlet.

This is a fairly common factory setup for water heater bypass.

[Dutch_12078]

There should be a check valve at the hot water outlet that prevents back flow into the heater tank when the 3-port valve at the cold inlet is in the bypass position. The check valves are a fairly common failure point when mineral buildup causes them to stick either open or closed. In your case, it likely stuck open of course. The check valve is usually pretty easy to replace if access is good. Sometimes they require some odd body contortions though. 🙂

[malexander]

I have an '07 Bounder. I had to cut an access hole in the closet wall, then cut the floor out of the area under the linen drawers to get to the back side of my water heater.

I tell you this because I lost all pressure to the hot side of all fixtures. I'm actually a licensed plumber. I wasn't sure what/how the
by-pass valve was doing. But, I found the mixing valve at the wh to be stopped up. I took it out, replumbed the entire wh area with my own by-pass valve set up. I installed a garden hose fitting with a ball valve on it so I could back-flush the wh if I wanted to.

[K_Charles]

Someone will post a picture but, there is a valve where the water goes in and a one way check where the water goes out. That valve should not let antifreeze in but it did. The three valve system might be a better way to go.

[casefarmri]

Thanks for info bumpy, but am newbie and WHAT???????????

[Bumpyroad]

assuming the shut off valve is after the T bypass pipe and before inlet into water heater, and there is an antibackflow valve in the pipe from bypass to outlet it should work?
bumpy