Water tanks filling and flooding over.

Cbigtez · Member

Water tanks filling and flooding over.

PeterD · Guru

Refer to the last example in this link - Adding mains pressure and hot water - The example is somewhat like the Jayco systems. You will notice there are two non-return valves (labelled no. 6) in the pipes. Jayco does not insert the one in the output line of the pump. They rely wholly on the pump to prevent the mains water from flowing back into the tank. The valves in the pump are not as robust as the non-return valves and will fail if you have been to towns with high water pressure. Also if a bit of foreign substance gets stuck in one of the valves that will allow a backflow (leak) of water back to the tank.

The cure for that is to add the non-return valve that Jayco leave out.

Some members will advise that the pump is failing so replace it. If you do that it is likely to fail again. Take no notice, just upgrade your system. That will be cheaper in the long run and be more reliable.

-- Edited by PeterD on Sunday 11th of April 2021 05:59:39 PM

watsea · Guru

As PeterD mentions, Jaycos often have this problem. Ours did. I mostly fixed with a Non Return Valve (NRV). Except in our van, there was very confined with space and close pipe fittings to install a NRV on the delivery side of the pump. I installed a NRV on the suction side (in the pipe from from the tanks) before the pump. Of course installed with the flow direction in NRV towards the pump. I was able to fit the NRV into the pipe under the van.
I say mostly fixed, as some places have very high water pressure and on a couple of occasions there has been back flow passing through the NRV causing the tanks to overflow. So merely turned the town water off and used water from the tanks, refilling before we left.

-- Edited by watsea on Sunday 11th of April 2021 10:25:23 PM

oldbloke · Guru

I'm going to check that on my van next week. Would be a bastard if the nonreturn valve failed on a big trip.

I would consider adding one good preventative modification.

Cbigtez · Member

Thank you for the info. I will fit the nrv in the pump line as recommended. Makes good sense. Cheers

Gus1949 · Senior Member

I removed the pump in my Jayco, dismantled it (easy) and cleaned out some very small pieces of gunk. Put it back together wondering if I achieved anything but problem solved. Perhaps the pump does act as a non-return valve, no idea.

watsea · Guru

Hi Gus,

I believe you are "correct".
After I installed a NRV, I read a post somewhere that the pump can stop backflow provided it is in good condition. My memory may be incorrect but I think the information was that seals can be replaced in the pump which stops backflow. I understand the seals are inexpensive. Either way, both seem an easy fix.