City Water Backflow to tank? Battery not charging?

[Santa & Pockets]

This is only the second extensive trip we have taken in our 2018 Gulfstream Kingsport 189-DD TT. The first night, we hooked up to the Park's water and plugged the hose into the City Water Inlet. We had both a filter and a regulator on the hose. The next morning we saw water spraying from the water heater vent and the fresh tank inlet. The tank itself was full and bulging. What did we do wrong?

In fear of the city inlet being damaged we have used the tank and pump only for this trip. The pump seems very loud at the kitchen sink. Is this normal?
Thanks for advice.

[NavyLCDR]

It sounds like the check valve that is internal to the water pump has failed. A "loud pump" is usually actually the pex piping in the trailer banging against a wall/component and finding where the piping is rubbing against something and putting insulation around it will quiet things down.

You can unscrew the inlet screen to the water pump and turn on city water, see if water comes out the inlet of the pump. If yes, the check valve in the pump has failed. Sometimes just running the pump will clear debris out of the check valve and fix it.

[Santa & Pockets]

Okay, thanks! I had wondered if there was a check valve, and 'internal to the pump' sounds sensible for the manufacturer. We'll test that when we reach home base.

[Texas Shriner]

Water pumps have a "max input pressure". Exceeding that pressure can result in water bypassing the internal check valve. The pressure specification on my surflow is 30psi. You may look into what your specification is and regulate accordingly.

[NavyLCDR]

Originally Posted by Texas Shriner

Water pumps have a "max input pressure". Exceeding that pressure can result in water bypassing the internal check valve. The pressure specification on my surflow is 30psi. You may look into what your specification is and regulate accordingly.

Since probably 99+% of RV water pumps draw water from a vented freshwater tank which is located below the water pump, 99+% of RV water pumps will actually have a negative inlet pressure (slight vacuum). I don't know of any RVs that have pressurized freshwater tanks so there is nothing to regulate on the inlet side of the pump.

City water will tap into the plumbing system on the outlet side of the water pump. Most RV water pumps have pressure switches set in the 55 PSI range which is what the water pump will pressurize the outlet side to. It's recommended to set city water pressure regulators to the same PSI as the shutoff switch of the water pump and to leave water pumps switched off when connected to city water.

[THenne1713]

There is CHECK VALVE inside pump to prevent this, but if not used, algae can grow and clog check from closing; drain, remove, disassemble and CLEAN. MIGHT require repair KIT or pump replacement.



(Some) who did not use PRESSURE REGULATOR w/ city water found all normal when they installed regulator?

[THenne1713]

30 sounds awful low? MOST pump run 40-50 (ON at 40, OFF at 50); Suspect you are reading label wrong?

[Texas Shriner]

Originally Posted by NavyLCDR

Since probably 99+% of RV water pumps draw water from a vented freshwater tank which is located below the water pump, 99+% of RV water pumps will actually have a negative inlet pressure (slight vacuum). I don't know of any RVs that have pressurized freshwater tanks so there is nothing to regulate on the inlet side of the pump.

City water will tap into the plumbing system on the outlet side of the water pump. Most RV water pumps have pressure switches set in the 55 PSI range which is what the water pump will pressurize the outlet side to. It's recommended to set city water pressure regulators to the same PSI as the shutoff switch of the water pump and to leave water pumps switched off when connected to city water.

That's nice and all; but, the solution can be found in a typical RV plumbing diagram and pump specification. The 12v pump can see line pressure and from the specification "Inlet pressure must not exceed 30 psi [2.1 bar] maximum...."

[NavyLCDR]

Originally Posted by Texas Shriner

That's nice and all; but, the solution can be found in a typical RV plumbing diagram and pump specification. The 12v pump can see line pressure and from the specification "Inlet pressure must not exceed 30 psi [2.1 bar] maximum...."

Look at the diagram the YOU provided. The water pump is drawing water from a VENTED freshwater tank. How is that pump going to get 30 psi at the inlet unless you block the vent on the tank and pressurize it to 30 psi, which will likely blow up the tank because it is not designed to be pressurized. Yes, the pump may have a 30 psi limit on the inlet side - and in an RV installation the only way it will see even 1 psi at the inlet is if something is very drastically wrong.

[NavyLCDR]

Originally Posted by Texas Shriner

That's nice and all; but, the solution can be found in a typical RV plumbing diagram and pump specification. The 12v pump can see line pressure and from the specification "Inlet pressure must not exceed 30 psi [2.1 bar] maximum...."

Look at the diagram the YOU provided. The water pump is drawing water from a VENTED freshwater tank. How is that pump going to get 30 psi at the inlet unless you block the vent on the tank and pressurize it to 30 psi, which will likely blow up the tank because it is not designed to be pressurized.

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