Bypass on-board tank

[WoodlandsCamper]

I currnetly have an Avondale Avocet 1998 with an on-board tank, on which I think the cons outweight the pros and therefore would like to bypass it, especially when on sites without hookup. The water pipes appear easy to modify by connecting the out of the external pump to the output pipe of the of the internal pump. As far as the wiring is concerned I first thought that the 2 wires to the internal pump could be moved to the external pump instead.

My concern is that the electrical feed to the internal pump is isolated when the 'bottom float switch' detects low water in order to prevent the internal pump from burning out. When not using the internal tank this switch will always be open and not power the external pump connected to the internal pump's wiring.

Has anyone tried bypassing on-board tanks and could help?

 

[craigmurray]

Hi, I don't know what the pipework is like on your van, but on mine (sterling elite trekker) i can turn a switch by the onboard tank and change the direction of the water so it closes off the tank and lets me draw straight from the Aquaroll outside. It might be worth looking at?

 

[WoodlandsCamper]

Hi Craig, thank you for your reply.

Unfortunately my van does not have the luxury of the switch like yours. I have now studied the wiring diagram and with a few strategic changes I can wire out: 2 relays, 2 float switches, a solenoid valve, the internal pump, and the internal pump panel switch. This leaves a simpler sytem with: the external pump panel switch, the pressure switch, and the external pump itself. The toilet flush is also electric and will now pump water from the external rather than on-board tank (it does not have its own header tank - no black bits from pink additives to worry about!!).

The pipework is relatively easy to change - just bypass the solenoid valve (which prevented water syphoning back into the external tank from the on-board tank) and the on-board tank itself.