Host Mammoth Question.

[brinson]

Is there a valve to switch between usING tank water and city water?

[brinson]

My last motorhome was a NRC toter and had a similar valve arrangement on it. So I wondered if the Host could be the same since it had the same symptoms if the valve was not closed.

[mike_kellie]

Brinson, thanks also identfying this valve. We always had flow but I never thought it could be better and the need to isolate the source. Can't wait to take it out and compare when hooked up.

[therobzilla]

Thanks, really appreciate you posting this!

[brinson]

Yes, on mine it is the vertical valve just before the pump. The valve running parallel to the floor is the tank drain valve. I labeled the city water valve myself. Dave at Host is aware of the no label as he informed me where the valve was. Hopefully, they will begin to label the valve.

[Rockfisher1]

Brinson, I took another look and the vertical pipe with the valve is on the suction side of the pump so that is the city water valve. I will mark it accordingly and thanks!

[Rockfisher1]

Thanks for the info Brinson! I've had my Mammoth for over a year and honestly did not know that the city water valve needed to be in the shut position when using city water. To clarify, I have 2 low point valves, a water tank drain valve (all 3 marked), and I believe the valve on the vertical PEX pipe just to the right of the pump is the city water valve. Yours appears to be marked and mine isn't. From you post, you may have labeled the valve yourself. I am correct in my assumption? Nothing in the owners manual.

[brinson]

This valve is on the suction side of the vertical run to the pump.

[brinson]

I printed the City water label as there was no label. This valve needs to be closed when using city water and open when using the water tank.

[therobzilla]

brinson wrote:
Ok, I talked to Shurflo and they instructed me to make one full turn on the allen screw for the pressure regulator. This did stop the cycling of the pump when not in use. I also talked to Host and there is a 1/4 turn guard valve that must been shut when connecting to city water. It was not labeled like all the other valves are. When the valve is shut it will prevent water from flowing backwards into the tank. There is no inline check valve on this system that I could find. Only the suction and discharge check valves in the pump head which are just rubber flaps and allowed the water to flow through the pump.

Can you post a picture of when this valve is located in the basement? I'm having the same problem, and the water pressure when hooked up to city water is HORRIBLE, and I have had it to the dealer twice to try to solve the problem. The pump pressure is actually better than city water connection.......

[brinson]

Ok, I talked to Shurflo and they instructed me to make one full turn on the allen screw for the pressure regulator. This did stop the cycling of the pump when not in use. I also talked to Host and there is a 1/4 turn guard valve that must been shut when connecting to city water. It was not labeled like all the other valves are. When the valve is shut it will prevent water from flowing backwards into the tank. There is no inline check valve on this system that I could find. Only the suction and discharge check valves in the pump head which are just rubber flaps and allowed the water to flow through the pump.

[crk112]

Do you just run the pump dry for a few mins or do you have to put some water into the fresh tank first?

I'm having the exact same issue that OP is having, city connection adds a couple gallons to fresh water tank after about 12 hours.

[Ste7of1]

Yes to pump check valve. I’ve had this happen before also. Dirt particle or something caught in check valve allows city water to back fill. Running pump for a while cleaned offending particles and seems to be fine since. Cleaned filter before pump just to be sure. Considered adding check valve after pump but have not as yet done that.

[brinson]

Most likely it is the check valve as the pump will run momentarily even when not being used.

[Kayteg1]

Ditto on checking check valve on the pump.
I did have system that would fill the tank from city water connection on motorhome, but doubt you will find it on camper.