Changing a tap microswitch

[GMJ]

We have been suffering from our water pump switching itself on for a second or so every so often, an occasions which I describe as a 'fart' from the water pump. I think I have narrowed it down to one tap in the bathroom which starts these farts after it has been used. At the moment firmly closing the tap after use seems to stop the noises but I'd like to explore whether a long term solution can be found and it seems possible to me that the microswitch may not be shutting properly.

Has anyone changed one of these? There are YouTube videos but I'd be interested to hear if anyone has done this themselves or whether I'll hand it over to the dealer to do.

Ta

 

[RichardHelen262]

When I had this in our motorhome it was just the pressure switch that needed a slight adjustment,
But now we also turn off the power for the taps when not using them

 

[merl]

Seems odd that the pump runs occasionally for just a second, are you absolutely certain that your system uses microswitches and not a pressure sensor?
The 'Fart' seems very typical of a pressure sensor system and 2 wires coming from the taps doesn't mean that the system hasn't been changed over by a previous owner (if there's been one)
Merl

 

[n brown]

a m/switched system means that when you open a tap , the switch is pressed and turns on the pump .
a pressured system has a m/switch in the pump that turns off when you turn the tap off . this is caused by the pump continuing to operate for a few seconds and pressure building up in the system operating the integral switch turning off the pump
as a m/switch is unlikely to turn on by itself ,i would say that you have a pressure system and the farting may be caused by a slight leak causing the pressure to drop and the pump comes on to top-up the pressure
hope that makes sense

 

[merl]

Second the above n brown post, and would add that the 'slight leak' would not necessarily be visible as a drip at a tap etc or a wet patch. More often the non return valve between the pump and the system is 'letting by' slightly and the pressure in the system simply lets water back into the storage tank.
Clean/replace the non return valve fixes the issue.
Merl

 

[r4dent]

I agree with others that these "Farts"are usually on pressure systems.

I suggest that you double double check to see if your system is pressurised.
What male/model/year is your van? Someone may be able to confirm the system it uses.

If it is pressurised the usual cure for farts is to adjust the pressure switch.

 

[GMJ]

Thanks.

The more I think about it the more I think it could be a pressurised system. It's a 2017 Autotrail Comanche.

Where will I find the pressure switch?

 

[n brown]

usually part of the pump, the bit on the end

 

[merl]

if you feel around the base of the taps and there's no wires then it's pressurised.
Post a few photos of pipework etc around the pump and peeps will get back to you with pressure switch and non return valve locations.
If you've got a leak or problem with the non return valve then adjusting the pressure switch so effectively the system now works at a lower pressure will often only make the farting problem occur less often.
Address the actual problem directly is my advice.
Merl

 

[AllanD]

There are some vans that have submersible pumps and a separate pressure switch outside of the tank. For example a lot of Auto-Sleepers use Whale systems like this. That's what we have and I've had to tweak the Whale pressure switch to solve the same problem. The Whale pressure switch also has a no-return valve (more of a flap) built into it which as posted above may need the occasional clean (or replacement).

 

[r4dent]

usually part of the pump, the bit on the end

On many MoHos it is a separate inline switch .

 

[ian81]

If it a tap with wirescoming out then it has a microswitch tat opertaes the pump. If the cable becomes a bit worn in the tap it can prompt odd behaviour.

I have changed one -it is not too difficult.

 

[groyne]

Our pump started operating randomly (pressurized system) in the middle of the night, very annoying. On investigation I found a small leak on a "Tee" piece. We now switch the pump off when not in use.

 

[QFour]

It has to be a pressurised system for faults like that. When a microswitch fails it is either pump on all the time or no water from the tap as the pump doesn't start. In a presurerised system a slight drop in pressure will fire up the system