Electrical Water pump always needs priming?

[Danniel jenkins]

Hi guys. Our water pump works great if your using it regulary, like every 10 minutes. But if you don't for say 1/2 hour or more, when you use the tap, it only pumps a little water and the pump is hell noisy, not primed. Operating the hand pump once or twice fixes it again for a while. If you leave the van sit, after a couple of hours, the pump will start to run, only just but you can hear slight vibration noises through the van. Any body heard of this and know a fix?


We took the van back to Jayco, they replaced the pump, But it still did it on the week end on our trip around Canberra. (got to check out cruzerdrivers stone guard )

 

[mfexpanda]

Sounds like the non return valve is not working

 

[Danniel jenkins]

Are they a jayco item??

 

[mfexpanda]

Are they a jayco item??

Yep.

 

[boots33]

We had the same problems with our one way valve. tried a couple of different caravan type valves but they all ended up leaking back after a while. In the end went and bought a decent brass one from a plumbing supplier and it has worked great ever since.

 

[Danniel jenkins]

We had the same problems with our one way valve. tried a couple of different caravan type valves but they all ended up leaking back after a while. In the end went and bought a decent brass one from a plumbing supplier and it has worked great ever since.

Thanks mate. Any idea where and what brand?

 

[boots33]

Bear in mind I am not a plumber so will gladly be corrected on the best way to do this but here is what I did. In our setup jayco had a small one way (check valve) fitted up near the manual pump tap. this valve never sealed very well and would slowly leak water back to the tank. it was so close to the tap it didn't take long for air to reach the valve and then it would quickly loose the rest of its prime.

So I fitted another valve further back towards the tank to stop all water from returning. You will still need to leave the original in place to stop the 12v pump from drawing air from the manual pump tap ( that is what was happening on my system once it lost prime).

Most of the time now even when the van has not been used for several months I can turn on power to the 12v pump and it doesn't even cycle on, I have to turn on the tap to check it is working and it never cycles on during the night either.

The type of check valve i used is like this one buy the smallest size and you will need to fit hose tails to suit your hose diameter. You can buy these on ebay but as it is for drinking water I went to a plumbing supplier and made sure the valve was suitable. Don't forget to use thread tape on the hose tails and clamps as well, it is very important to prevent air from being drawn in.

Here is a rough drawing of my setup

You can see how easy it was for the 12v pump to draw air once the manual pump tap lost its prime. If your 12v pump is in good condition and not leaking back you may get away with just replacing the original jayco valve.

 

[Danniel jenkins]

Cheers mate. Ill head to reece.

 

[boots33]

Be sure and let us know how you get on.