Water pump chattering

Ck all your outside faucets to be closed and your selector valve to be in the right position not half way.

Is this a new problem in a rv you've had for a while or is this a new rv to you.

First question: Does your plumbing system have an ACCUMULATOR in it? If this is a new issue and you have an accumulator, check the accumulator.

jyrostng wrote:
Is this a new problem in a rv you've had for a while or is this a new rv to you.

Because.....that's pretty much how it is supposed to work when pumping out of the tank.

Some are noisier than others; none are perfectly quiet.

If you run the faucet full blast, both hot and cold maybe, the pump probably will run mostly continuously. IF.....the pump is WAY oversized, it may never run continuously.

This is a new to us RV for the last few months. Chattering is a new problem since I decided to sanitize it today. Does not have an accumulator.

Remove the aspirator on one of the faucet outlets and see if it still cuts off and on. The pump may be pumping more volume than can come out the spigot if the aspirator is plugged up, they just unscrew. it may be full of white chalky water mineral residue.

The pump cuts off once a set pressure is reached.

Could be a bad pressure switch on the pump or I would suspect a restricted water flow allowing a pressure high enough to shut off the pump.

If it happens on all faucets restriction probably between the 1st faucet and pump most likely at the pump outlet.

We have noticed that when using the tank and pump and our selector wasn't turned all the way from "city" to "tank". Ours is in the water bay. Just a lever that you move side to side.

If you have a Shureflow 4008 "bypass" pump it has two adjustment screws hi and low pressure, that likely need adjustment. A common problem with these pumps. This pump is designed to run at a steady speed no matter the volume of water requested by the faucet the unneeded water is bypassed back to the tank, just like the fuel pump in your car operates. If it is some other brand or model likely something already mentioned above.

Lazy Days RV in Tampa has a great video on their site explaining this.

Note: the instruction manual specifically warns against using an accumulator tank with this type of pump so be sure of what you have prior to making mods.

If it is an older Shurflo pump (2088 422 144) there is an adjustment screw that controls rapid cycling. I can send you the service manual with the adjustment proceedure. Please advise if you want it.