Leak from top of flushpipe to WC cistern.

[Just_back_from_the_pub]

A leak is occurring from the top of the flush pipe where it connects to the siphon on as back-to-wall WC, which is about four years old. Is it preferable to fit a replacement securing nut and washer here or would it be best to dustbin the rubber washer and seal with silicone? If the latter, should the whole length of flushpipe inside the siphon thread be smeared with the silicone? Thanks for any advice.

 

[Softus]

I would fit it how the manufacturer intended, which I'm pretty sure excludes silicone, yet alone "smearing" anything.

If the rubber cone washer is worn or damaged, then get a new one.