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How to cap unused open sink pipes and water inlet?

Hi newbie here! We moved into our place and found some unused open pipes and water taps under the laundry sink, and trying to cover them up. We know a washing machine was removed from the laundry (they had two in there, we only have one) and so some water inlets and pipe may have become redundant in the process. Hoping to get some advice from the community 🙏

In the photo:

1. Open end of S trap - is there any cap for this? Or any other way to close it?

2. Small open pipe - this spurts out water and floods the cupboard when water gets poured down the sink above so need to close. Is there a cap for this?

3. Bottom half of cold water inlet - you can see I had tried to seal this with a blanking cap, thread tap and fibre washer, but it still leaks. Done it twice already, very sore from being in the tight space with no room to move or turn that wrench... The same setup has worked for the hot water inlet, so not sure what's wrong. Any ideas to fix it? Or just try to redo it again?

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EricL

Hello @housie

Welcome to the Bunnings workshop community. It's sensational to have you join us and thanks for sharing your question about your sink pipes.

Let me recommend some parts that will cover your exposed pipe work.

For number one, I suggest combining the Holman 50mm PVC DWV Male Threaded Iron Adaptor and the Holman 50mm PVC DWV Push On Cap. Join the two together as firmly as possible and screw it on top of the open "S" trap.
For number two, use the Deks PVC Trap Dishwasher Outlet Cap, loosen the threaded clip and push tightly onto the nipple of the trap and tighten the strap to secure.
For number three, remove the leaking brass cap you've installed and place a 19mm rubber washer from the Kinetic 12mm and 19mm Nut and Tail Washers kit at the bottom of the cap. Remove the old thread tape and apply a new set. Re-attach the brass cap and make sure to check for leaks.

That should cover all the open and leaking sections of your sink pipes.

If you need further assistance, please let me know.

Eric

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EricL

Hello @housie

Welcome to the Bunnings workshop community. It's sensational to have you join us and thanks for sharing your question about your sink pipes.

Let me recommend some parts that will cover your exposed pipe work.

For number one, I suggest combining the Holman 50mm PVC DWV Male Threaded Iron Adaptor and the Holman 50mm PVC DWV Push On Cap. Join the two together as firmly as possible and screw it on top of the open "S" trap.
For number two, use the Deks PVC Trap Dishwasher Outlet Cap, loosen the threaded clip and push tightly onto the nipple of the trap and tighten the strap to secure.
For number three, remove the leaking brass cap you've installed and place a 19mm rubber washer from the Kinetic 12mm and 19mm Nut and Tail Washers kit at the bottom of the cap. Remove the old thread tape and apply a new set. Re-attach the brass cap and make sure to check for leaks.

That should cover all the open and leaking sections of your sink pipes.

If you need further assistance, please let me know.

Eric

housie

Thanks for your quick response @EricL ! We'll try out your advice and recommendations.

I thought fibre washers were appropriate for hot and cold water taps use. Is it the wrong part to use in this case? It did look a bit small although it was spec'd for 20mm, and somehow worked for the hot water one.

JacobZ

Hi @housie,

The fibre washers can be used with these taps, I'd suggest its connection just wasn't perfect the first time.

Follow the steps Eric has provided above, but don't overtighten the brass cap. It's possible that overtightening can crush the washer allowing a small amount of water to get through.

Let me know how you go and if you require further assistance.

Jacob

housie

Thanks @JacobZ ! That's handy to know. I had screwed the cap on fairly tightly thinking that was required. Did it twice, once without a washer, once with a washer. Will try with less tightening next.

While on the topic, I layered the thread tape at about 7 layers as suggested by the tape package instructions. Sound about right?

redracer01

Hello @housie

That should be just about right. Too much thread tape will make it difficult to screw the cover cap on.

Red

housie

Thanks @redracer01 ! That makes sense, will do.

housie

I've capped the open pipes but failed (still leaks) upon trying another fibre washer with capping the cold water inlet. Thought I would give the fibre washer another go since I had another new one lying around. No good. It had seemed to have sat OK but guess not really after all.

Will get the rubber washer @EricL 's recommendation and try again...

Unscrewing the cap again after it leaked for the third time and checking out what became of the washer:

EricL

Hello @housie

Please give the rubber washer a go and make sure not to over tighten the cap. You're after a firm fit, but not overly tight. Please make sure to remove all the old tape and put new tape on.

Eric

housie

The rubber washer was much easier to position right than the fibre one! Finally fixed!

Thanks guys for your help.

EricL

Hello @housie

Job well done! Nothing is more satisfying than getting all the leaks plugged up. Please check the area occasionally for the next 24 hours just to make sure that there are no slow leaks. If no leaks occur, no repairs are needed.

If you need further assistance, please let me know.

Eric

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