Pond with waterfall

[GBBUDD]

sounds like a diverter valve to me shuts water down in one direction and sends it to another

 

[poconojoe]

I doubt that tee is a check valve.
If any of them are a check valve, I would vote on the vertical one in the second picture of post #12

 

[Neil Cheney]

I doubt that tee is a check valve.
If any of them are a check valve, I would vote on the vertical one in the second picture of post #12

I agree!

 

[Neil Cheney]

I doubt that tee is a check valve.
If any of them are a check valve, I would vote on the vertical one in the second picture of post #12

I misread your earlier post and the tee coupling below the filter must be a diverter because the metal finger turn diverts water to a drain. The upper big white plastic fitting (hose connects to upper pond and filter) looks like the check valve as it has a finger turn which I managed to operate. I couldn’t see a finger turn on the big white plastic fitting (hose connects to pump inlet) and I’ll take a good look at it tomorrow when the weather is better. By the way, what is the -impose of the finger turn? Is it to control how much water is allowed to pass through the valve?

 

[poconojoe]

https://www.gardenpondforum.com/attachments/6cc6820e-2de2-4936-ab92-7231aed95fb1-jpeg.127691/
I don't know...I think a check valve would have an arrow on it for direction of flow. That looks more like a type of union for means of easy disconnect.

 

[Neil Cheney]

https://www.gardenpondforum.com/attachments/6cc6820e-2de2-4936-ab92-7231aed95fb1-jpeg.127691/
I don't know...I think a check valve would have an arrow on it for direction of flow. That looks more like a type of union for means of easy disconnect.

I think we are there now and many thanks for your help

 

[Neil Cheney]

I think we are there now and many thanks for your help

Just an update on progress.... I fitted a brand new check valve which worked only twice. The pump is on a timer and this morning the water level in the upper pond had dropped causing the water level in the lower pond to rise above the top of the liner with consequent water loss. It’s a complete mystery as I never had a problem in the past two years and it would seem that I can rule out the check valve as it’s new. Could there be any other reason for the reverse flow? I recall that this problem only started around the time I added TAP No More Blanket Weed treatment to the pond if that’s any help.

 

[addy1]

There could be some weed stuck in the check valve which keeps it open.

 

[Neil Cheney]

There could be some weed stuck in the check valve which keeps it open.

Thanks and your pond project looks quite an undertaking. Please post further pictures with work in progress. Intermittent prob;ems are harder to resolve than complete failures and I just inspected the non return valve which is really easy on the McAlpine unit and found it completely clean. I suppose the blanket weed killer is breaking up the weed and some is occasionally getting trapped in the valve which is flushed away on subsequent pump running cycles. I could keep the pump running 24/7 but would still need to stop it to clear the pump pond strainer.