Fixing Toilet Not Flushing - How to Repair & Replace Plastic Siphon Valve/Washer on Cistern for Free

If your toilet isn't flushing but the cistern fills with water then the most likely problem is the plastic flap inside the siphon has broken so no suction pressure is generated. This video shows how to replace the plastic to get the toilet flushing again as normal. Best of all there is zero cost, the parts required are available around the house for nothing.
I'm not a plumber so any work you do is at your own risk - I repaired this toilet using basic instructions that needed very little effort or knowledge and no cost to me other than my time

[@mudandstars182]

It would be helpful if you explained how to remove the blue thing in the first place

[@sorchajones1788]

Great hack! There’s already a hoard of tubes about how to take out and replace a flush system in a bog already. I’d seen suggestions that DPM could be used to make a new diaphragm but I haven’t got that. But genius solutions people found here, include using plastic from a chocolate box, bit of lino, tarp, plastic wallet and so on are very helpful. Thanks Andy and the bunch of inventive people who shared how they did it.

[@LottieBronte]

Thank you for this. I bought a replacement syphon as there wasn't much difference in that and the diaphragm washer in price. However...syphons arent all the same and I now think I have realised the difference between the one I bought (single unit) and a dismantleable one like the one in my cistern. As a result, I have now repaired the washer with some plastic film, tightened up the unit with a bit of string and stabilised it with an empty shampoo bottle and it's working fine - all at a cost of nothing. Im not a plumber, just a woman who isn't afraid of a bit of DIY. I'm planning on changing the toilet soon so it's only a temp repair...but lesson learned and this syphon I bought will be swapped back at the shop for a more easily serviceable one. if I hadn't seen this video I would not have had a clue what was wrong.

[@alexorme2679]

Worked great, thanks for the info. If anyone is reading this and doesn't have the quick release for the unit, know you will have to take the whole cistern off the wall and toilet, which is a bit more involved. I am no plumber, and the whole process took me about an hour and a half.

[@chrisrecardo2643]

25 minutes and cistern flushing stronger than ever. Good simple repair, zero cost, cheers Pal.

[@ajvw]

Zero cost is always a good fix!

[@ozric4122]

10 points for great info, but only 3 for camera work ;)

[@jeffhunter7330]

Cheers Andy! Took it apart as suggested and exactly the same problem. Cut out some plastic as you described and brilliant, all working well and cost me £0.00. Happy days!

[@barrythompson]

Brilliant - Made mine out of one of those plastic protective sleeves for 12" records , would not have been able to have known what to do without this video - thank you.

[@TavsIsAbout]

Thanks mate! Just did this exact thing with a Thomas Dudley system and it’s worked perfectly!!

[@MediaBrighton]

Thanks, fixed mine by cutting out the plastic from the bottom the poppadom packaging. Saved me £80 call out!

[@ajvw]

Glad it helped!

[@junxs1]

Thanks, just watched your video and fixed my toilet. Used plastic from a Heroes chocolate box as its tougher plastic than what was originally in there. Thanks again.

[@konigsfavourite]

any chance you could show how to disconnect the mechanism? I need to replace e the plastic too and cannot figure out how to disconnect or get access to it.

[@thelatentimage4734]

You are a life saver! This was such an easy fix, cut out a new piece of plastic (some old thick black plastic tarpaulin), reassembled and it works perfectly again. Thanks!

[@avarubyplaytime3798]

You are a star, mine has been dodgy for about a year and never got round to sorting, fixed in 5 minutes using a plastic paper wallet 😁👍

[@ajvw]

Glad it was of help!

[@LFOVCF]

I recommend you use one of those plastic file pockets with the poppers. it's slightly stiffer plastic, but it's bulletproof. Just cut out of the pocket the shape of that star grill

[@ajvw]

Thanks, that's useful info to know

[@scottom100]

Absolutely brilliant video ! you have saved me a lot of stress and money. I used a plastic folder as it was very similar plastic to the original. There was no pin on my mechanism, it simply pulled upwards and i was then able to access the damage piece, cut a new piece and replace. It works like new. Thanks

[@darrylroff3932]

Absolutely fantastic. It took me hardly any time at all to sort the problem out. Best of all though is that it didn't cost me a single penny. Many thanks.

[@jaycee3958]

Thank you worked a treat and done in 5 minutes

[@peterhughes4414]

The diaphragm is designed to fail so you buy a new one, knowing this I made a new diaphragm from some old kitchen lino, WOW, works better than the origanal plastic , I also super glued the lino to the base.

[@mindgeek120]

Thanks man appreciate the video

[@subhan741]

Thank you very much I fixed my flash

[@downcas]

Thank you it works 💯

[@Phaedrax2]

The handle on my toilet often comes loose, I take the top off the cystern and tighten the plastic washer and all is well until it gradually loosens again. This time, the handle will not pull up the part that flushes, it all seems a bit flimsy so not happy about applying too much force. What could be stopping the 'plug' from being pulled up to release the water?

[@morganshaw3663]

Andrew, you don't make clear that this is only this quick and easy because your siphon is a Dudley - otherwise you'd need to fully dismantle the cistern to get at the flap valve. Also, I have tried replacing a failed flap valve with a home-made replacement in the past and the plastic must be of the right size, thickness and flexibility or you will run into problems. Fine if you're happy to tinker but it may be easier just to spend a few quid on one from a plumbers merchant. Make sure you get the right size!

[@E-Kat]

You didn't show the most important bit how to take the thing off and how to replace the plastic!!!!! How do you stick the plastic???? I suppose you won't reply.....so it was waste of my time!!!

[@castlecan]

I'll have to do that...

[@lormace3352]

Sadly didn’t learn how to get it out and put it back in

[@misterocain]

Unfortunately, in most cases the siphon can only be removed by releasing the bottom nut. This can be a very tricky job with the type of toilet shown in this video as the but is hidden.

[@bonbon-fj4nr]

Hi Andy, Our plumber just installed 3 derwent mcdee siphons in our three toilets and none of them are flushing properly. He figured maybe that there was an issue with the plastic diaphragms, that they were not flat or damaged in the heat in the back of his van. He replaced one of the diaphragms but the result is the same. The toilet flushes on the first flush sometimes or needs several pushes of the handle on other occasions. What could be the problem? Mostly, they require several pushes of the handle. This is not normal.

[@richardpegg9265]

hmm - some quite big missing bits there - you didn't happen to work for the haynes manuals in the 80's did you

[@johnzo70]

About as helpful as a hole in the head

[@marcjackson995]

Mumbling non professional.

[@Jay-uz4kv]

Will be watching another video to find out how really to fix....

[@jwoodavant]

Don’t wait any longer!!!!

[@tweetypie25]

Very poorly explained, How does the mechanism come out? I was informed the middle washer had to come out!!between seat and cistern??

[@Haider-Hashim-world]

You haven't shown anything,how you remove

[@therightreverandmarcuiusmc2355]

Video is as much use as an ashtray on a motorbike.

[@ajvw]

Funnily enough some people seem to find it helpful, maybe they like ashtrays on bikes :)

[@therightreverandmarcuiusmc2355]

.........haha........FRIENDS & FAMILY

[@glutoxim]

@@therightreverandmarcuiusmc2355 what a prick

[@therightreverandmarcuiusmc2355]

@@glutoxim Friend or family?

[@conorobrien53]

This was the worst youtube video I have ever watched. It gave very little detail on fixing a toilet flush and showed pictures of completed refitting of toilet parts without a video demonstrating how to fix the toilet problem. Would rate 3 out of 10.

[@ajvw]

Sorry it didn't help you. Others seem to have had more success with it

[@ifcukin8mufc168]

And how did you replace the plastic washer ...!

[@ajvw]

If you mean the large plastic disc then it just fixes on the base of the syphon

[@jammy-44]

This is badly explained tbh with you my friend

[@apollo8972]

That part has been through a lot of shit cut it some slack.

[@geraldgamwell3634]

N

[@barkspawn]

Draw the rest of the fucking owl

[@aramariella]

u wont even show how to remove n install…poor video mate👎