Water system problems

[Col3691]

Hello

I've recently replaced my Whale 12v Submersible Water Pump with a new one because it died. When I came to use the water system last time out I noticed the pump was coming on as soon as I turned on the main switch. It's supposed to only operate when a tap is opened and turn off after the tap is closed (no microswitches on taps due to age of van)
I thought the problem might be the In-Line Pressure Switch so I replaced that too, but it's still the same.
I've followed the instructions for the pressure switch but still no joy.
Just wondered if anyone has experienced this issue and has any pointers/advice.

Many thanks
Col

 

[audiorob]

In case you don't have it already here is the Whale instruction sheet - I have laminated one to keep in the caravan!

https://www.rainbow-conversions.co.uk/user/downloads/Whale/Adjusting%20your%20pressure%20switch.pdf#:~:text=Ensure%20the%20system%2C%20including%20the%20heater%20is%20full,the%20pressure%20switch%20locknut%20in%20an%20anti-clockwise%20direction.%29

when I have set mine I am amazed how much adjustment can be needed.
Sorry if this is too obvious for you! Initially both the hot water tank and the pipework has to be filled - so open the hot tap furthest from the pump, then the next, then the last, repeat for the cold - to ensure no air lock present. (Can't remember how many litres it takes - maybe 20 in total?) As you say once primed and ready the pump should run while a tap is opened, and only briefly after it s closed as the system re-pressurises and cuts the pump power.
Ensure the yellow drain tap is fully closed (not physically obstructed by anything) and also worth opening and shutting a couple of times to make sure there is no foreign body within it.
Have you checked for any leaks?
The pressure system is pretty simple - a diaphragm operated switch opening and closing to operate the pump but is sensitive to power supply - and may for example need readjustment if changing from EHU to battery.

 

[Col3691]

Thanks for the help and advice. I'm going to give it another go and see if it's maybe something I'm missing or doing wrong 👍

 

[izzy]

I had the same problem though the pump was OK. I changed O rings and NR valve but eventually had to change the entire switch unit (50 quid ish) since then it has worked as it should
As audiorob says the switch is sensitive to voltage differences and so may still need a slight adjustment sometimes at the start of a trip, also the system only needs a very small leak to stop it holding the low pressure that it needs to switch off.
When it works it is a good system, when it doesn't you need something very heavy to kick.

 

[ProfJohnL]

I had the same problem though the pump was OK. I changed O rings and NR valve but eventually had to change the entire switch unit (50 quid ish) since then it has worked as it should
As audiorob says the switch is sensitive to voltage differences and so may still need a slight adjustment sometimes at the start of a trip, also the system only needs a very small leak to stop it holding the low High pressure that it needs to switch off.
When it works it is a good system, when it doesn't you need something very heavy to kick.

 

[Col3691]

Just an update on a my Whale water system.
I followed the instructions for the new In-Line Pressure Switch to the letter. I can get the Pump Run light to come on by adjusting, but the pump carries on running after the taps are closed.
I noticed that some water trickles from the housing where the pump plugs in while the pump is running after closing the taps. I'm guessing this is due to pressure build up because after the taps are closed the water has nowhere else to go. The plug on the old submersible was a better/tighter fit and never leaked. But this is a new Whale submersible so my guess is it should be the same.
I put some PFE tape around the O ring to try to create a better seal but it's still the same.
Could the problem lie with the new submersible because it's not as snug fitting and with the slight leaking?
I'll be taking the van for a service in a couple of weeks so I'm guessing they'll be able to tell me what the problem is and how to resolve it 🤷‍♂️

 

[ProfJohnL]

If there is a leak of any sort in the pipework or fittings, that will cause the pressure in the pipe work to drop, and that in a pressure switched system will l eventually turn the pump back on. Often this will result in the pump pulsing on and off

If the leak is too big the pump may not be able to develop enough pressure to turn the pressure switch (and pump) off

 

[Col3691]

It's looking likely that the new Whale submersible pump I recently bought could be the culprit then. I'll have to take it up with them I guess.