Siphonic pan over-filling and draining slowly

[waterrat]

Hi, A plumbing newbie needs advice!

Have replaced the siphon and refill valve in close coupled loo, cistern works/refills OK but the siphonic action of pan doesn't.
Pan fills to brim and then empties slowly. Water level doesnt drop in pan when first flushed.
I have checked for blockage in pan outlet as far as I can reach, doesnt appear to be blocked. Ideas anyone?

 

[Resolute]

You get a bomb in a syphonic pan - is that ok?

 

[SimonJohns]

There is defiantly a blockage. It may not be in te back of the pan but you have got one in the pipework


Find the drains outside. Lift a few covers. If no joy there. Start running taps and seeing where it goes.

When you find where they all go it will make it easier to find what's wrong

 

[mikegas]

Did you use the correct syphon for a siphonic wc? if so then it sounds like the washer hasn't sat right

 

[waterrat]

sorry to be stupid but could you describe 'bomb' is it the torped shaped tube that fits inside the down tube of the cistern siphon and connects into the pan?

 

[waterrat]

I think the drains OK as were checked couple weeks ago with a cctv camera. The problem with overfill/slow emptying only started after replacing the cistern inards. There is a flow regulator in the new Fluidmaster refill valve where there wasnt one before (also a fluidmaster refill of same model) could this be the problem?

 

[mikegas]

The fill valve isn't the problem, it's sounds as if the domed shaped washer that seals the tube from the syphon to the pan hasn't sealed properly

 

[david williams]

syphonic wc has a venturi dart in bottom of syphon did you replace it or throw it away with old syphon,if you refitted it into new syphon it may be the rubber on it may have perished and needs replacing.

 

[Best]

On double syphonic toilets, both the small domed washer on bottom of bomb & the large cistern to pan washer must seal right. Unless you have broken the bomb putting cistern back on pan, then fault is one of these washers. The pan will fill high up & then drain slowly, which fools people to think it is blockage.

 

[BLOD]

I agree with the above replies, sounds like the bomb isn't seated properly or isn't there any more

it looks like this

 

[waterrat]

Thanks for info. I have replaced the venturi but note that the rubber has perished and think this is the problem, am trying to source the appropriate rubber replacement.

 

[waterrat]

Thank you for info. I think bomb rubber the problem and am going to replace this when I find one that fits!