Our flojet water pump in caravan does not seem to selfprime. Filled tanks and turned on tap. Not much pressure and pump does not cut off when tap turned off. Any suggestions.

Question edited for clarity.
Question moved to Flojet Pumps.

It should come out in puffs when the FloJet is pumping and then stop when it senses pressure. If it is a constant leak. It needs replacing. Co2 is toxic in a closed room. On a beverage pump, your supplier of whatever the beverage is (beer, soft drink syrup) should replace it free of charge.

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Nozzles are plugged? Remove nozzles, clear lines, nozzles and screens.

If still a problem, rinse tank and fill with a few gallons of water. Find a convenient point to disconnect pump outlet side from all nozzles. Try pump, if same problem, keep opening connections closer to pump outlet until blockage is cleared.

it is compressed air and is set around the 50psi mark
the operation is that the pump starts and pressurizes the system
when the 50 psi is reached the pump switches off
you turn a tap on and the bladder starts the water flow at around the 40 psi mark the pump cuts back in and pressurizes the system when you turn off the tap the pressure goes back to the set pressure and turns off
unfortunately bladder systems are out dated and don't allow for more than one tap in operation
There are cheaper and far more precise controllers on the market to control pump operation that also have pump protection where by the pump is stopped if there is a lack of water supply with in 1 minute

Is it whirl-pooling because the water is too shallow? One thing you can do to prevent this is to lay a piece of plywood over it. It will float and keep it from whirlpooling and sucking air.

Pump probably needs to be serviced. It probably pressurizes a tank and when that tank reaches a pressure the pump is turned off. But just guessing.

your pressure tank is water logged drain water in tank then start pump, that should fix it. if it happens again down the road just drain tank again. reason is there is no bladder in the tank.

It could be leaky check valve . The check valve keeps water from run back into the tank. It may be stuck partway open or dirt or scale may be keeping the valve from shutting tight . Hope this helps.

It sounds like the bladder in your pressure tank is water logged. Turn your pump off and open a tap and let the pressure off. Once the water has completely stopped coming out of the tap go to your pressure tank and pump air into it. There should be more water come out of the tap. Continue to pump are in until you reach the pressure recommended for your tank and there is no longer water coming out of the tap. Close the water tap and turn the pump back on and this should fix the problem. If it does not you will probably need a new pressure tank. The bigger the pressure tank you have also will make the pump work less. I prefer a smaller one myself as there is less change in the shower pressure when the pump cycles than with a bigger tank but this is just a matter of prefference. Some people prefer a larger tank as it uses less power by the pump not working as often.

the diaphragm may be puntured so no pressure developing

The water pump is usually started by either
1. a drop in pressure when a tap is opened, and an in-line pressure switch turns the pup on

or

2. a microswitch on every tap.

which ever system your caravan has, it will be one of those thats not kicking in the pump.