Problem with fresh water system

[ExcitedToRv]

Friends, who own a 2014 New Horizons Majestic, asked if I would post the below:

Having a problem with my fresh water system. When I am on city water which is working correctly I am also filling the fresh water tank. This happened to me one time a few years back when I turned on the pump while also using city water. Now the pump is not on and is not hot to the touch and the valve is turned to city connection. I’m wondering if replacing the city water/tank valve is the proper fix. Any other suggestions?

[Old-Biscuit]

Two possibilities:
1) FILL Valve leaking thru/not closed

2) Pump internal check valve leaking thru...allows city water to backflow thru pump

[DTVGuy]

Originally Posted by Old-Biscuit

Two possibilities:
1) FILL Valve leaking thru/not closed

2) Pump internal check valve leaking thru...allows city water to backflow thru pump

Suspect #1 above. Your rig is old enough to have this happen. Mine is same age.
Here is what could be causing this to happen in any rig including NH.
If a water softener is not used minerals can get into the plastic valves of which the NH is full. (So are other rigs.)
If one tests the water around the US, and we do at each stop, 85% of the places we test have hard to very hard water. That means minerals and those minerals get in the valves / fittings and cause leaks including the check valves and the toilet valves. ("Ask me how I know this" on a previous rig.)
FWIW, we highly recommend an external water softener for any rig and especially in areas of hard water and the SW, along with Florida, have especially hard water.
This is a bigger deal then some might realize over longer periods of full timing.
Available on Amazon - Recommend the following for cost vs. size vs. capacity.
https://www.amazon.com/Go-OTG4-DBLSO...70_&dpSrc=srch

[caps]

I have replaced the valve with no success in fact I think it got worse. Getting ready to replace the water pump.

[JPFretired]

More than likely it's you water pump check valve. No need to get a new pump just order the check valve and replace it. Always use a water regulator and soft water tank will help a lot.

[daallen]

Originally Posted by JPFretired

More than likely it's you water pump check valve. No need to get a new pump just order the check valve and replace it. Always use a water regulator and soft water tank will help a lot.

I have a 2017 Majestic and have experienced water going into the fresh tank. I have cleaned the strainer and looked up the check valve in case it needs to be replaced. It seems to be built into the pump, does that mean that you would have to replace the pump?

[dadej]

Are you talking about the Anderson fill valve? There is lots of talk about issues of overfill with this valve. Having had several RV's and no check valve failures I doubt it is the check valve in the pump. On a side note it takes me about 30 minutes to fill my 100 gallon tank. Anyone have this same result?

[DTVGuy]

"I doubt it is the check valve in the pump. On a side note it takes me about 30 minutes to fill my 100 gallon tank. Anyone have this same result?"[/QUOTE]

If you care to, take the input hose side off the pump. Turn on the outside water with the fill valve off. I.e. putting water into the coach, not the fresh water tank. If no water is coming out the input side of the pump - the side going to the fresh water tank - then its not the pump passing water into the fresh water tank. This should be pretty easy to check.

Unless NH has changed something and according to the New Horizons IB - there are only two ways water can get into the fresh water tank - Via the fill valve or back through the water pump in the wrong direction.

On the question of 30 min to fill (totally) the 100 gallon tank - Yep. The pipe size in the rig pretty much determines that will be more or less the case depending on pressure, etc.