Two water system problems, HELP!

[Gareth111278]

Hi
i have an on-board tank / pump / accumuilator type water system.
It has two faults, 1. The pump will not run unless you by-passthe switch in the base of it. i've got it by-passed & we just use the master switch as/when we need water. Is there a common fault or easy fix to this? I think its a Sure-Flo pump , it got the switch in the base, a clear inlet housing & is mostly blue & dome shaped.
The second thing is I've pressed the car tyre valve on the accumuilator & no air came out! what pressure should this run at?

Any advice welcome
Gareth

 

[Damian]

Problem 1...........New pump
Problem 2............20psi

 

[Gareth111278]

Short & to the point!!
Thanks! I've got a spare whale in line pressure switch , I'll try using that& see how I get on. It's an old thing with an adjuster screw on the top but it'll be better than a new pump!

 

[RayS]

Check the existing pump by connecting 12v directly - but only for a few seconds, the pump won't like running dry.

Easily done usuing a pair of croc clips and the car battery or some other source of 12v d.c.

Then you will know if it's the pump that's failed before you have to fiddle about with the other pressure switch.

Another way if you have a test meter is to test the pump for being open or short circuit - one way you will get a very high ohm reading (ideally infinity) and the other zero ohms - not sure what the 'ok' reading will be but neither infinity or zero.

 

[RayS]

Check the existing pump by connecting 12v directly - but only for a few seconds, the pump won't like running dry.

Easily done usuing a pair of croc clips and the car battery or some other source of 12v d.c.

Then you will know if it's the pump that's failed before you have to fiddle about with the other pressure switch.

Another way if you have a test meter is to test the pump for being open or short circuit - one way you will get a very high ohm reading (ideally infinity) and the other zero ohms - not sure what the 'ok' reading will be but neither infinity or zero.

 

[Gareth111278]

The pump works fine with the switch by-passed the only problem is the switch in the base of it not working.

Good tip on testing the resistance of the motor though

 

[forestgump]

is it the switch then as pump dose work iff bypassed

 

[Gareth111278]

Thats what I was thinking, it's on the 'to do' list ...

 

[Gareth111278]

Yeah!!
Finally got it sorted! Fitted the whale switch & put 20psi in the accumulator .
It switches on & off nicely now.
One final question, there's 20psi in thd accumulator with the water at atmospheric pressure, once I start the pump what should that increase to before the pump cuts off?
Or am I just being pedantic now?!

 

[colin-yorkshire1]

whats this!! spammer season

( parksy informed )

Thanks Colin, I've removed the spam and booted the spammer in case anyone is wondering why Colin mentioned it

(Parksy)

 

[ProfJohnL]

Check the existing pump by connecting 12v directly - but only for a few seconds, the pump won't like running dry.

Hello Ray,
As general point you are correct waterpumps do not tollerate dry running very well. The submercible types often rely on the water passing through the body of the pump to cool the motors, and to keep the shaft seals intact. But in this case the OP has stated its a Sure-Flo pump with the built in pressure switch. These are diaphragm pumps and have no shaft seals and do not rely on water cooling. Running dry is not recommended, but it usually isn't a problem for them.