running toilet minimal access to close coupled bottom entry

[Tirglas_7]

hi

i have an ideal standard close coupled toilet shoe horned in to a small under the stairs area in my 5 year old new build.

bit blurred sorry



the toilet continually runs heavily, if i pull the float all the way up it does not cut off the water am i right in thinking the fill valve is goosed? is there a way of changing the top of the fill valve without disturbing the lower part that passes through the toilet?

Access down the side of the toilet is as pictured tight, and due to the design of the toilet itself it looks nigh on impossible to get anything on to the fittings.
if it does require a new complete fill valve assembly, Is there anything out there tool wise i can use to get on to them to remove the old valve, and more importantly install and tighten the new one successfully?

many thanks for your time

 

[seco services]

More likely just needs a new diaphragm.
PT no sv21267.

Check the old one more likely damaged/split.
Isolate the water supply and you can twist the top of the float valve and it comes apart, hold the float valve lower down aswell and you won't twist the whole valve.