Your Help with Fluidmaster 3514B Cistern Valve

[Ray1000]

Having not worked on one of these I'm unsure what can and can't be done.

The downstairs toilet cistern occasionally overflows into the bowl.
It happens when a bath is run upstairs, or when the toilet is flushed upstairs.
The float is fully underwater when the water level is in it's "normal" position.
I started by lowering the float clip to the bottom of the stainless rod but it made no difference.

Q1. Are there any further adjustments to make ?
Q2. Are there any available parts that need changing ... seals ... washers ?
Q3. Can the top part only being changed leaving the standpipe in place ?
Q4. Are the ones available a direct replacement for a 3514B ?
Q5. Does the top part come off simply to examine it properly ?
Q6. What's the unused grey nozzle in the second picture for ?

Thank you very much
Ray

 

[Deleted member 267285]

It may need a new seal, but it’s touching the cistern, so could just be getting stuck?

 

[Ray1000]

Thank you for that, I’ll wedge it away from the cistern tomorrow and check the movement.

Are the seals readily available?

 

[Deleted member 267285]

Are the seals readily available?

Yes they should be, including the sheds.

 

[Ray1000]

Thanks, it’s at my sons house I’m going to have another look at it this morning.

 

[Ray1000]

You were exactly right Chris, I moved it away from the cistern and the float now works as you would expect.

Still mystified by the relationship between the upstairs toilet and bath, and this downstairs toilet being spurred into action.

Thank you again
Ray

 

[Ray1000]

On checking today it was still overflowing into the bowl.
Bought a new unit with the intention of just changing the valve body leaving the standpipe in place.
This idea is frowned upon in the instructions so I bought and fitted a new seal for the existing valve.
Several hours later it seems to be working fine and maintaining water level.
Flushing the upstairs toilet doesn't set the downstairs off now - I'll have to assume it was drawing air in thro the faulty seal.

 

[Ray1000]

Regarding my questions in post #1

Q1. Adjustable valve body & float height
Q2. The main seal is at Screwfix
Q3. Yes, frowned upon but nothing to lose
Q4. Yes
Q5. Yes, slide locking ring up and simply lift the body from the standpipe. The seal cap is a one eighth ACW turn bayonet fitting.
Q6. Nothing

 

[Ray1000]

A few days later it’s still working fine … Total cost £1.59p

 

[Elsa TLC]

You were exactly right Chris, I moved it away from the cistern and the float now works as you would expect.

Still mystified by the relationship between the upstairs toilet and bath, and this downstairs toilet being spurred into action.

Thank you again
Ray

View attachment 344361

I like to fit the fluid mastered as they are the most reliable. But sometimes due to cistern design they dont work, because they do hit on the side.

Happy it worked for you.