Lunar Water System
(Venus, 2019 Model Year)
Master Troubleshooting & Diagnostics Matrix
| Error Code / Indicator | Symptom / Meaning | Possible Cause | Step-by-Step DIY Fix | Suggested Actions |
|---|---|---|---|---|
N/A | The water pump runs very noisily but isn't actually pumping any water. | The pump has an air lock, which tends to happen after the water container's been refilled. | Unplug the pump from its socket to let it flood, then plug it back in. When refilling the container, the right order is: unplug, put the pump back in the container, then reconnect. | DIY Safe |
N/A | Water pump fails to deliver water | Air in the system | Turn the pump off and shake the pump assembly around in the water, then switch it back on. Alternatively, check the assembly is seated fully into its housing. | DIY Safe |
N/A | The water pump doesn't run at all. | Blown fuse, faulty connections, or excessive continuous running | Check for blown fuse or faulty connections. If due to excessive continuous running, replace the pump. | DIY Safe |
N/A | Water pump will not run | The pump may be faulty, or a wire may have come disconnected. | Confirm the pump's isolating switch is switched on. | DIY Safe |
N/A | Water pump cycles on/off | Battery voltage may have dropped too low (10.5V or below); there may be air or water leaking at the taps or piping; or grit may be holding the non-return valve open. | Adjust the switch and/or recharge the battery. Check the taps and piping for air or water leaks and re-adjust the pressure switch. Using the exploded drawing, take out the three assembly screws so you can reach the non-return valve and clear out any grit. | DIY Safe |
N/A | The water pump motor runs steadily and won't stop. | The battery voltage may have dropped too low (10.5V or below), or there may be an air lock in the pipework. | Check every connection in the pipework. Take out the adjusting screw - if the motor keeps running, the pump most likely has an air lock. Switch the isolator off, then reprime the pump. | DIY Safe |
N/A | The fresh water level is below 25% full while the pump's switched on. | Onboard water tank level has dropped below 25%. | A message appears on screen along with a 30-second audible beep. | DIY Safe |
N/A | Pump not working | Fuse blown. / Pump turned off at control panel. / Setting incorrect. | Fit a replacement fuse of the correct rating from the fuse table. Switch the pump on using the pump button on the control panel, and confirm its setting (internal/external) matches what you need - if it's wrong, ask your dealer to change it. | DIY Check / Tech Fallback |
Frequently Asked Questions
Q: How do I connect and prime the fresh water system for the first time?
1. Top up the fresh water container and stand it beside the wall socket on the caravan's offside external wall. 2. Check that the pump isolator switch on the inside control panel is off. 3. Turn on the kitchen's hot tap, with every other tap shut. 4. Put the pump into the container outside, making sure it sits right down at the bottom. 5.
Lift the wall socket's lid and push the pump assembly plug fully home into it. 6. Fit the dust cover over the container opening. 7. Switch the pump isolator switch back on at the control panel. 8. Once the kitchen's hot tap runs freely, let it go a few seconds longer to clear any trapped air, then turn it off. Do the same again for the cold kitchen tap.
Q: How do I prepare the water system for winter storage to prevent frost damage?
a. Drain the whole system. b. Open every kitchen tap (lever taps should be lifted to their central position) and leave them open for good. c. Do the same for the bathroom and shower taps, including the shower's on/off control rose. d. Give the shower head a shake to clear any water held inside, then disconnect it from the hose. e.
Take out the cold water drain plug, if your caravan has one - it's usually underneath, near the water inlet socket. f. Clear any water left in the pipework at the inlet sockets and the in-line pressure switch. g. Unplug any cartridge or in-line filters from the plumbing. h. Shake out submersible pumps and keep them somewhere dry. i.
Drain the external shower's bridge connection on the Ultraflow housing, either by fitting the shower connector or opening the valve with a tool.
Q: How do I prime the water system if my caravan is fitted with a submersible pump?
1. If there's air trapped in the submersible pump it won't prime properly - free it by gently shaking the pump while it's underwater in the tank, with the power switched off. 2. For an external submersible pump, get it into the water first, then connect it to the van's side.
Q: How do I adjust the pressure switch?
1. Once the system's properly primed, close every tap and shower. 2. Keep the power supply on. 3. Turn the adjusting screw clockwise to tighten it - the pump should start running. 4. Open one cold tap partway so water flows at roughly a pint every 15 seconds. 5. Slowly back the adjusting screw off again until you hear the switch start to click - at that point it's correctly adjusted.