Dudley Turbo 88 siphon - reduced flush issue

[Harry Bloomfield]

https://www.screwfix.com/p/thomas-dudley-ltd-turbo-88-siphon-9/8461f

I have the 9L version installed in two toilets here, of that model and at first I could not get the reduced flush to work reliably. Both were installed new, to replace some older flush units. Enquiring with Dudley they suggested the fill valve was set too fill to too high a level. It would sometimes flush at reduced sometimes not, by holding the flush handle down. A workaround was to press the handle twice and hold it down at the second press, where it would work reduced every time.

Reducing the fill level helped a little, but didn't completely fix it, besides reducing the level reduced the effectiveness of the full flush - meaning it would sometimes requires several full flushes to clear the bowl. Both units have the same issue.

Has anyone found a fix, or found that their 88 works as designed on the reduced flush please?

 

[just pumps]

Isn`t it a question of moving a plastic bung from one place to another on the valve or am I thinking of something else?

 

[Harry Bloomfield]

Isn`t it a question of removing a plastic bung from one place to another on the valve or am I thinking of something else?

To be honest, I cannot remember - I fitted them three years ago and spent ages checking and rechecking, plus asking Dudley for advice. If a bung needed to be adjusted, it was done. Besides it does the reduced flush sometimes, it just doesn't do it reliably unless it is pressed twice and held.

The cistern is marked with the 9L level mark, I had the water set on the 9L originally, but Dudley suggested the valve may not give a reduced flush if the level is too high, so I reduced it to an inch below. It seemed to make the reduced flush more likely to work, but not guaranteed. I gave up then..

I am back looking at it again, to try again to find a fix. The fill valves are also I think Dudley - a small blue plastic float close to the valve, which sort of screws into a short arm on the valve to set the fill level.

 

[Hugh Jaleak]

Isn`t it a question of removing a plastic bung from one place to another on the valve or am I thinking of something else?

It is, and these plugs need to be fitted correctly or it wont work as designed. Really cant see anything else that could be wrong, the idea is when the water level drops below the opened hole in the unit, it breaks the syphonic action and stops it flushing. If water level was too high, it would have flush more water to drop the level to the required point before air could get in.

 

[Harry Bloomfield]

I have had another look at it and it seems not to be entirely dependent on water level in the cistern, whether it manages the short flush or not. A few tests, suggest it does the short flush correctly, 2 out of 3 times.

Here are the install instructions for an 88, but it is not identical to those two I have fitted. www.thomasdudley.co.uk/images/pdf_instructions/Dudley%20Turbo%208

My version has the white plug in the neck, and what look like two more white bungs, one above the other where the 'yellow conversion flap' is marked on the second page. The two are in a vertical black panel. Both white bungs (if that is what they are) are fitted. Like this - http://www.thomasdudley.co.uk/bathroom/cistern-components/turbo-88-syphon.html

If I remove the plug in the neck, it does a short flush every time, whether the flush handle is held down for a short flush or not. I did not attempt to remove either of the other two white bungs in the black part of the base / valve section.

 

[Hugh Jaleak]

Does it still do a full flush if required with the plug in the neck removed? Basically, any half flush syphon will have some kind of aperture to provide an air break when the water level drops to that point, to break the suction and finish the flush. Holding the handle down blocks that aperture to provide a full flush when required, There's nothing more to it.

 

[just pumps]

If I remove the plug in the neck, it does a short flush every time, whether the flush handle is held down for a short flush or not. I did not attempt to remove either of the other two white bungs in the black part of the base / valve section.

I believe one of these bungs needs to be removed however I am pretty certain the model I have in mind had one bung not two so you had a choice of where it went.

 

[Harry Bloomfield]

If you mean the single plug close to the wire pull loop, when that is removed it does a reduced flush no matter how you press the handle.

I have done a little research and a few are having a similar issue getting the 88 to reliably perform the reduced flush. One suggestion I have yet to test, is to glue the rubber washer to the blue plastic washer, on the rod, just below the wire pull loop.

 

[Harry Bloomfield]

I believe one of these bungs needs to be removed however I am pretty certain the model I have in mind had one bung not two so you had a choice of where it went.

I have checked and they are two bungs, in the main body, plus the one higher up near the wire loop. The two bungs in the body are to adjust the full flush capacity.