City water is filling fresh water in 260IBL... Help!

[Flybob]

Originally Posted by IronCobra

So, we just back from another short RV trip. The dealership sent me a Camco brass Backflow Checkvalve to install on the inlet side of the pump (between the freshwater tank and the pump) instead of sending me another pump. I installed it correctly and I still have the problem. .

If it were me, I would have installed the back flow valve on the outlet side of the pump. Some backflow valves rely on the pressure in the system to get a good seal.

[IronCobra]

Originally Posted by Flybob

If it were me, I would have installed the back flow valve on the outlet side of the pump. Some backflow valves rely on the pressure in the system to get a good seal.

Well, most RV pumps looks for about 40psi of back pressure from the outlet line to disengage pump operation. If you put a backflow valve on the output, you may cause the pump to either never come on or to cycle constantly since the valve will restrict or hold pressure and confuse or prevent the pump from seeing the pressure it needs to cycle. Plus the valves are specifically designed to be installed on the inlet side of the pump.

Because a backflow valve is simply a spring set to open a rubber/plastic seal at a given pressure (usually around 20psi) it will(should) seal back without needing backflow to create or seat the seal.

[blwnsmoke]

Originally Posted by IronCobra

So, I spoke with both my dealer and a local Chaparral dealer who both claim they have very little knowledge of the plumbing in these coaches. I decided to take it upon myself and add a ball valve to the Waterfill hose to/from the Freshwater tank. Hope this resolves my issue. The plumbing back there is a nightmare.

The first and last pics are after pics. Middle one is the before. This should resolve any issue with water going into the Freshwater tank unwantedly. Chaparrals only have 1 hose (not including the low point drain) going to/from the tank. The valves control whether that single hose is used to fill or pull from the tank. The problem had to either been water back flowing through the pumps check valve (which I already added an additional check valve to with no luck) or a leak in the OEM diverter valve.

My jaw dropped when I unscrewed the panel to access the back of the water pump when I winterized.. I would have never thought that it would have been a bunch of hoses going ever direction being nicely covered so we can't see it. Sheesh!!

[IronCobra]

So, I'll make an attempt to describe what takes place . More for humor than anything.

1. Freshwater Inlet diverts water into either the tank or the RV
2. If going to tank, then the outlet and inline line are simply reversed and water is forced into the tank through a single hose.
3. If going to the RV, the water is diverted to 4 additional pipes that back up to the pump (assuming the check valve in the pump works), the other pipes go to the RV plumbing through 1 hose, the diverter valve below the water control panel, the Hot Water Heater, and another for the outside Shower (also at the control panel).
4. The pipe that from FROM the pump is directed from the 3-position ball valve to the left which diverts water either from the pump or directly from the water inlet. Either way, the System Use and the City Water connection both allow water to be used from the City Water connection when connected. This apparently is by design
5. The hot water pipe has 3 outlets to accept incoming water from the pump, feed the RV, and the Shower (including panel low point)
6. The freshwater Inlet line has a junction to allow the connection of a whole RV water filter system.

1/2 of the piping is PEX, the other Half is Camco FWH (Fresh Water Hose) braded lines.
The ID (Inner Diameter) is 1/2" on all hoses

All pumping connections are made using Cinch connections 1/2"