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Super_Dave's avatar
Super_Dave
Explorer
Oct 24, 2020

Asking for a friend

He is trying to winterize his 5th wheel. Antifreeze flows through the cold water side but not the hot water side. System is set to bypass and winterize. He tried blowing air through it and no air passing either. If winterize mode is switched back to RV mode, air passes through the system.
  • PawPaw_n_Gram wrote:
    If there is any possible to install something wrong / opposite to the directions on an RV, most of us will install it the wrong way the first time.

    mobeewan wrote:
    The water heater bypass valve(s) is normally on the back of the water heater.


    Most of the higher end fifth wheels and motorhomes I see have a remote handle to turn the water heater bypass valves on the outside near the city water input. I'm sure the actual valve is located close to the water heater, but the cable pull handle is on the outside as described by the OP

    Actually, the valve is on the other side of the handle. It cuts off flow to the dedicated cold water line that runs to the water heater and redirects to a red, hot water line that ties into the rest of the hot water system.
  • If there is any possible to install something wrong / opposite to the directions on an RV, most of us will install it the wrong way the first time.

    mobeewan wrote:
    The water heater bypass valve(s) is normally on the back of the water heater.


    Most of the higher end fifth wheels and motorhomes I see have a remote handle to turn the water heater bypass valves on the outside near the city water input. I'm sure the actual valve is located close to the water heater, but the cable pull handle is on the outside as described by the OP
  • The handle is most likely a 90 degree rotation and has a positive stop to prevent further rotation.

    As you said he might have to remove the handle and reorient it properly. Make sure the valve is set to pass water through the line when the handle is inline with the hose and perpendicular to the hose when shut off.
  • The water heater bypass valve(s) is normally on the back of the water heater.
  • It's a B&B Moulders bypass valve on the outside of the trailer where the fresh water connections are. We have diagnosed that the wrong side of the valve is open when in bypass. I'm wondering if it is as simple as the handle orientation? Does anyone know if this valve will rotate 360 degrees? He installed this new this past Spring and may have put the handle on in the wrong orientation?
  • Sounds like the water heater bypassing valves are not set up properly, or (depending on the system) malfunctioning. The only malfunction I can think of that would cause the problem as described would be a check valve on the water heater if it's so equipped and it's a one valve bypass setup.

    My guess is that it's a three valve bypass setup, and the middle valve (that connects the hot and cold lines) is not being set properly.

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