Waterpump question??

*Kol*

Should the water pump in a motorhome run constantly or just when you run the taps?

Malta1

Mine only runs when when the tap is turned on.....any small leak on the tap will result in the pump running all the time

peasant

There are two types of pump, immersion pumps or pressure pumps. Neither of them should run constantly, especially not "dry" as that will kill them quickly.

Immersion pumps are immersed in the tank and switched on/off by little switches at every tap. A faulty switch will result in a dripping/running tap and no great damage.

A pressure pump is plumbed into the piping somewhere near the tank and maintains a constant pressure on the water system. As soon as you open a tap, pressure is reduced and the pump starts pumping.
The danger here is that if you have a leak somewhere other than at a tap or at the toilet (where water can run off into the waste water tank) your pump will keep on pumping until it has emptied your whole fresh water reserve into wherever the leak is. And then it will run dry for another bit until it goes up in smoke

So a pump that is running constantly is not a good sign and if yours does that, make sure to turn off the pump switch (that's what it's there for) and go search for the leak / dripping tap.

*Kol*

Not a leak thankfully. Sticky presssure switch on the pump. A few gentle taps on the pressure switch shut the pump off!!!:D Will be an easy fix to disassemble and free it out.

*Kol*

I have shortened the distance the plunger for the pressure switch has to travel to make the swicth shut the pump off. Looks ike the pump is not producing enough pressure to make the switch. Works perfectly now and the pressure from the taps and the shower is still good.
The previous owner changed the leisure battery which was probably killed by the pump running all the time.

chrisblack

Hi Kol

I'm having a slight problem with my bathroom tap... switch doesn't always kick in, or is very slow to kick in, when the tap is turned on... any idea where I can find the switch for bathroom tap?? Will it be in the bathroom, or elsewhere - it probably just needs a spray of WD40, I would imagine.

Thanks

Chris

*Kol*

Hi Chris,

I only have one pressure switch located on the pump at the tank. So the action of opening the tap causes a pressure drop at the pump to get the pump running.

If your system has switches at each tap does the pump operate ok when the kitchen tap is opened?

chrisblack

Hmmm.... When I turn on the sink tap theres a click and then a whirring as the pump kicks in and water comes out... When I turn on the bathroom, theres a click and then sometimes a whirring and water coming out... I was guessing there was a switch on each tap???

Chris

*Kol*

This is pump I have. You can see the pressure switch on the end of the pump on the right. The square piece with the red wire coming from it. Is this what you have?

peasant

Chrisblack

If your taps look like normal household taps, then you most likely have pressurised system and a pump similar to the one in kol's picture.

If they don't, they probably have a switch somewhere which switches on the immersed pump in your tank. Try to look at your taps from underneath ...if there are wires ...there's a switch.

Could be that your switch isn't making proper contact anymore and needs some encouragement ...could also be that the water just has to travel longer to the tap and therefore takes that bit longer to arrive. Some of these immersed pumps are not great at holding the water in the pipe and let it run back into the tank after a while.

Edited to ad:

If your pump only "whirrs" then it's most likely an immersed pump with switches at the taps. Pressure pumps usually make what's best described as an almighty rumble

chrisblack

Thanks Peasant

The taps don't look like normal household taps..

There are wires under the taps, so I'll try and locate a switch... it seems to be intermittent as to whether the pump kicks in when I turn on the tap, the switch certainly sounds to "switch on", which is why I can't work out why the pump isn't pumping... so maybe I need to play with the wires.

Chris