Cant get my WATER PUMP going, any advice appreciated.

chrismarshall3 · Oct 03, 2017 8:15 pm

Hello everyone,

Anyone with experience with water pumps, advice would be appreciated.

I have a Grundfos Scala 2 water pump connected to a channel water supply pipe about 40m away using 1-1/2 inch rural poly. The pump is not that high above the water supply and ¾ of the line is flooded.

When I start the pump it runs constantly for 2-3 mins then stops saying there is no water. I opened the pump as it was running and there is water getting in. I tried pouring some water into the pump to prime it but it did the same thing. I have a valve closed on the outlet so there is nothing going out yet.

homeone · Oct 03, 2017 8:16 pm

saveH2O

chrismarshall3 · Oct 03, 2017 9:22 pm

homeone · Oct 03, 2017 9:23 pm

saveH2O is an expert when it comes to these matters.

He's been tagged to capture his attention so he'll hopefully reply to you shortly.

SaveH2O · Oct 04, 2017 12:29 am

chrismarshall

I have a valve closed on the outlet so there is nothing going out yet.

Open the valve. You must always have water flowing through the pump when it is operating.

I take it that you have only just started using the pump and that you have you primed it but have you also fitted a meshed check valve at the pick up?

chrismarshall

I have a Grundfos Scala 2 water pump connected to a channel water supply pipe.....

Am I right in assuming that the pipe draws from an open channel? You also need to make sure that the pick up isn't generating a free surface vortex.

chrismarshall3 · Oct 04, 2017 9:07 am

There is no check valve the line inlet pipe connects to the channel pipe which draws from a water channel. I have no access to the actual channel but the line I connect to is flooded to a certain height (about 15cm below pump level).

chrismarshall3 · Oct 04, 2017 9:11 am

thanks for replying I appreciate it.

SaveH2O · Oct 04, 2017 10:55 am

chrismarshall3

There is no check valve the line inlet pipe connects to the channel pipe which draws from a water channel. I have no access to the actual channel but the line I connect to is flooded to a certain height (about 15cm below pump level).

The Scala2 has an inlet and outlet check valve fitted. When drawing water from a source lower than the pump, an additional check valve would usually be fitted near the end of the pick up but given that it draws from a flooded pipe and provided that the pipe is always flooded at the pick up, there shouldn't be a problem. Note that check valves are also called non return valves, one way valves, suction valves and foot valves although foot valves also have a mesh strainer.

The Scala2 is a very good pump.

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chrismarshall3 · Oct 04, 2017 1:55 pm

Thanks

I tried opening outlet and outlet taps but it only trickles out.

I then tried opening pump up, closing the outlet and filling the pump with water to fill all the inlet lines back to the source. It's been filling for 20 mins still not full. Pipe is only 30 m is it possible i have a leak under ground somewhwre ?

chrismarshall3 · Oct 04, 2017 6:57 pm

Ok so I got a neighbour to push his water into my pipes and it comes gushing out both iblet and outlet so pipes are not the problem. The problem is with my pump it does not achieve pressure.

SaveH2O · Oct 05, 2017 12:12 am

chrismarshall3

I then tried opening pump up, closing the outlet and filling the pump with water to fill all the inlet lines back to the source. It's been filling for 20 mins still not full. Pipe is only 30 m is it possible i have a leak under ground somewhwre ?

I wish that I could see that pipe or a diagram at least. Is the channel pipe totally flooded? You mentioned that the channel pipe draws water from the channel, how does it do this? I can't see how the channel pipe could be pressurised.

The Scala2 has a check valve on the inlet side, I can't see how you can be unsuccessfully filling the pump for 20 minutes unless the pump is flowing back into the inlet pipe but you do say that you were trying to fill the inlet lines. Given what you say and if this is the case, you cannot fill the inlet pipe if there is no check valve fitted to a flooded section because water finds it's own level. If the pipe isn't flooded, then the pump won't work and will register no water. The pump and the pipe must be primed.

IF water is being delivered to the pump, you can increase the pump's outlet pressure but if someone has been messing around with the controls, I would reset it back to the factory setting. The manual will show you how to do this, I would prefer that you follow the manual but there are only two buttons to press for 5 seconds at the same time.

If you think that the pump should be working with the piping that you have, then you need to test the pump so as to eliminate or confirm the inlet pipe as being the problem. Just set the pump up for the test as per the video below.

https://www.youtube.com/watch?v=Wv1ELf4Emfw

chrismarshall3 · Oct 05, 2017 9:23 pm

So it turns out the pump was faulty or became clogged with channel debris.
It was not sucking hard enough to even become primed.

I have taken it in for repair and will probably need to add a filter in the line.

SaveH2O · Oct 05, 2017 9:37 pm

That is why I asked if you had fitted a meshed check valve (foot valve). I hope that the pump wasn't damaged.

The next challenge will be how not to clog the foot valve. Good luck.