water line noise

Your Shurflo pump which pumps water thru your water lines and helps maintain water pressure thru your water lines should shut off when you switch over to City water. It does in my Winnebago. There is no pump check valve in my Winnebago to my knowledge. I can turn on my Shurflo pump while on city water. I've done this in the past with low water pressure at a hook up site. In my Winnebago there is no other water pump in my City water system just the Shurflo pump.

There is a check valve in our pump, if there wasn't city water would flow back through the pump and into the fresh water tank. We turn our pump off when on city water. You can leave it on but if pressure drops enough when using water the pump will kick on to bring pressure up.

Hank MI wrote:
There is a check valve in our pump, if there wasn't city water would flow back through the pump and into the fresh water tank. We turn our pump off when on city water. You can leave it on but if pressure drops enough when using water the pump will kick on to bring pressure up.

Thanks for the info Hank, I wasn't aware of that.

2 check valves in supply side of RV plumbing system
City water inlet has a check valve (plastic plunger/spring/o-ring assembly)to prevent water from back-flowing out thru connection when using on-board pump

On-board pump has an internal check valve (diaphragm) to prevent back-flowing thru pump when using city water connection


IF you are 'hearing' noises when pn city water and water is flowing it most likely is the cheap plastic junk check valve in city water connection


OR it could be one of the cheap plastic junk check valves used in Water Heater.

Many RV Mfgs use a check valve in WH Tank HOT out
Winnebago likes to use one in HOT out AND one in COLD IN

So you would need to listen carefully at city water in and at backside of water heater with water flowing to ID which cheap plastic junk check valve is causing noise...........noise means on its way to failure

Old-Biscuit wrote:
2 check valves in supply side of RV plumbing system
City water inlet has a check valve (plastic plunger/spring/o-ring assembly)to prevent water from back-flowing out thru connection when using on-board pump

On-board pump has an internal check valve (diaphragm) to prevent back-flowing thru pump when using city water connection


IF you are 'hearing' noises when pn city water and water is flowing it most likely is the cheap plastic junk check valve in city water connection


OR it could be one of the cheap plastic junk check valves used in Water Heater.

Many RV Mfgs use a check valve in WH Tank HOT out
Winnebago likes to use one in HOT out AND one in COLD IN

So you would need to listen carefully at city water in and at backside of water heater with water flowing to ID which cheap plastic junk check valve is causing noise...........noise means on its way to failure

That assumes the problem is a check valve. He already said it sounds like the water pump running so I'm going with that. Low water pressure at the park, pump on while on park water, the pump is going to kick on from time to time.

Are you using a pressure regulator and do you have your inlet valve turned to city water and your pump shut off?

Sounds like a case of water hammer.

Hank MI wrote:

Old-Biscuit wrote:
2 check valves in supply side of RV plumbing system
City water inlet has a check valve (plastic plunger/spring/o-ring assembly)to prevent water from back-flowing out thru connection when using on-board pump

On-board pump has an internal check valve (diaphragm) to prevent back-flowing thru pump when using city water connection


IF you are 'hearing' noises when pn city water and water is flowing it most likely is the cheap plastic junk check valve in city water connection


OR it could be one of the cheap plastic junk check valves used in Water Heater.

Many RV Mfgs use a check valve in WH Tank HOT out
Winnebago likes to use one in HOT out AND one in COLD IN

So you would need to listen carefully at city water in and at backside of water heater with water flowing to ID which cheap plastic junk check valve is causing noise...........noise means on its way to failure

That assumes the problem is a check valve. He already said it sounds like the water pump running so I'm going with that. Low water pressure at the park, pump on while on park water, the pump is going to kick on from time to time.

IF on city water and pump control is ON then city water pressure has to drop low enough for pump start set point to make up.
That would be 35# if standard on demand pump or 45# if upgraded on demand pump.

Failing check valves 'chatter', 'hummmmmmmm', 'pulsate', vibrate' and make all kinds of other noises.
On demand pump noises are ;whirrrrrrrrrrr' or 'buurrrrup'

So OP just needs to check that pump control is OFF and then if noises continue...it's a check valve

If noises do stop then turn pump controls back on. And investigate why city water pressure is so low that pump runs......probably city water inlet check valve failing :B

If the OP is using a pressure regulator and the pressure output from that regulaor is lower than the pump pressure switch than the pump may cycle.