Pump Has Gotten Loud on New Rig

[Al Humboldt]

Our new Boldt’s water pump has gotten louder and makes random grunting noises when water is not running. Clues?

[akeagle]

Originally Posted by Al Humboldt

Our new Boldt’s water pump has gotten louder and makes random grunting noises when water is not running. Clues?

My first thought was that the pump mounting fasteners may be a bit loose. The "grunting" sound makes me think there might be an additional problem with the system not holding pressure and the pump turns on in short bursts to re-pressurize the system.

[Eagle5]

Hi Al,
The Eagle5 did the exact same thing. The correction (after consulting with Winnebago and then the dealer who did the fix) was to adjust upwardly the pressure setting of the water pump. Below is how my water pump would sound.

Water Pump Grunting

[raytaylr]

I had a similar problem. The pump does rattle the water lines and is sandwiched tight into its spot. Mine just would not shut off except for short times, that's when I discovered air in the water inlet side of the pump.

Turns out the water fill connection that looks just like the shore/city water line connection T's into the water line between the water tank and the pump. That connection, like the city line, has a check valve at the hose connection point but it checks outgoing pressure and air was being drawn in through that connection.

I blocked that inlet with a 3/4" plug (threads don't match but was tight enough to seal) and no more air draw.

I called Winnebago, they are sending me a replacement connector with the same check valve thinking maybe the spring in mine is weak? Doesn't seem logical to stop in coming air/water with an outgoing check valve. This needs a switch or on/off lever or a incoming check valve that is deactivated when a hose is connected.

I wonder how many others have this happening and don't know it and just assume its normal and switch off the water pump.

[Winterbagoal]

As others have suggested, probably air in lines causing pump to short cycle. If possible, check all pex fittings for tightness, and start with the in/out lines and screen trap at the pump itself. There's probably a loose fitting or other leak somewhere along the tubing. I found one in our Sunstar under the sink, at the back of the 6 gal water heater. Both lines in/out had not been tightened at the heater at the factory. Poor QC in general, I'd say. Easy fix, though.