How to fix leaking rainwater tank flow diverter?

[CooperK]

Hello everyone, 

We've just moved into a new home that has a newly installed rain water tank. Not being very clued up on these, last week I tried to open the black nosel on the first flow diverter, thinking it was where the garden hose attaches and when dripps started coming out I tightly closed it, having thought I'd messed up. We now realise that it's supposed to drip! What's happened now is that no water gets through and it's leaking from the connecting pipe which is slimy and smells bad. 

I've tried losening the black nosel but nothing happens. Is it all backed up with gunk I wonder? 🤔. I'd love to know what to do here to solve the issue as rain water feeds into the laundry and washing machine. If we need a professional, who do you even call? 

Humble thanks from a total outdoors newbie!

 

[JacobZ]

Hi @CooperK,

Welcome to the Bunnings Workshop community, it is fantastic to have you with us.

What you are looking at is called a first-flush diverter. It is a device fitted to a rainwater tank system that improves water quality by preventing the initial, most contaminated runoff from entering the tank. When it first rains, debris such as dust, leaves, and bird droppings is washed off the roof; the diverter captures this “first flush” of dirty water in a separate chamber. Once that chamber fills, cleaner rainwater is automatically directed into the tank, while the captured water slowly drains away. This simple system helps keep the tank water cleaner and reduces maintenance needs.

With the dripping head being blocked, I'd say it is backed up and not operating as it should.

To fix this, you'll want to unscrew this cap here -

If it is on tight and you can't unscrew it by hand, you can use a pipe wrench to rotate it off. If you wrap the cap in a rag before slipping the pipe wrench in place, it will protect the cap from damage that could be caused by the metal of the pipe wrench.

Now, there might be a float inside the diverter that you wouldn't want to lose down the outlet pipe, so you might want to put a bucket under the pipe once the cap is off to catch it. If there isn't one, there's no issue, but it's best to be prepared in case.

Once the pipe has been cleared, clean everything up, insert the float if one falls out, then screw the cap back into place. Once it is back in place, you'll want to adjust the black nozzle so that it slowly drips. You don't want water to be streaming out, but you don't want it to be completely sealed as the pipe needs to fill with water so the water can flow over the top and into the tank.

After a good downpour, it is worth repeating this process as any leaves or sediment that washes off the roof will be captured in this pipe. 

Once you've done it once, you will understand the process and you can repeat as required. This will help keep the water in your tank from being contaminated with sediment and other solid matter.

Let me know what you think and if you have further questions, please don't hesitate to ask.

Jacob

[CooperK]

Hi Jacob, 

Thanks so much for your advice! I did everything you suggested, it all worked, then at the last minute when in setting the first flash diverter, which had a stick filter, the floater, which didn't realise was there, fell into the pipe. I had to take the shield away to reinsert. So bummed. Any ideas as to getting that out? I have no idea how far the floater went. 

Thanks again! 

[CooperK]

I guess I need to buy another floater to insert as well?

Thanks 🙏 

[JacobZ]

Hi @CooperK,

I can't imagine the outlet pipe would have been plumbed into your home's sewage system, meaning there's a good chance it was plumbed to your stormwater. If you head to the front of your house, there's a chance you could have a stormwater outlet that runs to the kerb. Have a look there; if you run your garden hose down the outlet pipe, it might flow to the street. Unfortunately, if the outlet pipe runs elsewhere, then it might be gone for good.

If you can't locate it, then you can purchase a replacement First Flush Sealing Ball assuming you have a 90mm pipe or above. Just head to your local store's Special Orders desk or place an enquiry with our Spare Parts team. They will be able to get a price from our supplier Rain Harvest and then order it for you.

Let me know if you have further questions.

Jacob

[CooperK]

That's amazing, thank you Jacob for all of your advice today! Off to Bunnings ! 😊

[JacobZ]

No worries @CooperK, I'm glad I could help.

If you wanted to future-proof, and you've got enough clearance, it might be worth grabbing a Holman Finish Collar with Grate (in the correct diameter for your pipe) and using some Protek Red Priming Fluid and Protek Type N Blue Cement Solvent to glue it in place. 

That way, you can clear the mechanism without having to worry about any floats doing a runner.

Good luck!

Jacob

[CooperK]

Will do! Thank you 🙏