Nuevo water pump

Alan,

With my 2019 Nuevo, if whilst the water pump is switched off the hot water pressure drops, all 10 litres of water in the Combi drains back through the systems NRVs into the freshwater tank over a period of 3 to 4 hours and certainly overnight.  The drop in water pressure can be caused by:

1.  A leak which might be very small and therefore difficult to detect.  I had a very small drip coming out of the Truma drop valve which was contributing to the pump to coming on for about 4 seconds every 15 minutes or so.

2.  An open hot water tap or one that isn't completely closed.  My shower mixer tap was very sensitive to this.  If it wasn't completely pressed home it leaked a tiny bit and it wasn't noticed because of the shower pipe and any drips going into the shower tray under the mat and then the waste water tank.

3.  A drop in water temperature.

4.  NRVs that are failing to stop water flowing back though them.  Whale has told me that this will only happen with the NRV in their pressure switch if it is contaminated with debris.  Mine wasn't checked for debris.  Instead it was replaced with a new one and it still allows depressurised water to pass back through it into the fresh water tank.  Its even more remarkable than this as the depressurised hot water flows back through two other NRVs as well - one on the inlet side of the Truma drop valve and an NRV placed between the pressure switch and submersible pump by the dealer who didn't know that the pressure switch had an NRV.  I have discussed this with two other AS owners with the same Whale water system.  Both did the same experiment - pressurise the water system, switch the pump off and then open a hot tap to depressurise it, leave it overnight and then switch the pump back on in the morning.  One reported the same as me that all the water had drained out of their Combi back into their fresh water tank and the other that their NRVs had stopped this from happening.

The irritation of my pump coming on periodically for 4 seconds of clicking and whining, with all the taps tuned off, continues and we continue to switch the pump off overnight which among other things stops the toilet flush from working.  We have found that if the water heater is switched off, especially if it was previously on boost or hot, or it automatically reverts from boost to eco, the water pump comes on much more frequently.  We even found that an overnight drop in ambient temperature after the water heater had been off all day was sufficient to make the pump come on at least once during the night.  My previous three caravans didn't do this and the last one had a pressurised water system albeit with a diaphragm pump.

Gassygassy,

Out of interest did you fit a Shurflow water filter strainer/filter to your Shurflow pump or just rely on the redundant Whale pump’s strainer?  Similarly did you fit an accumulator with the Shurflow?  I have read they are not necessary.