Toto Ultramax - Won't fill

About a year ago we unexpectedly remodeled all three of our bathrooms at once and added Toto Ultramax while we were about it. (Make sure your little boy understands the idea of turning the sink off, pariticularly if he has blocked it up to wash his hands after going potty...) We love them on a day to day basis but one of them has a recurring issue that I know is fixable as the fellow who installed them has fixed it but I don't see how.

Every few months the toilet stops filling after a flush and no more water comes in. Our contractor showed me a little hole in the top of the valve that controls the fill. He cleaned that out and put it back together and it worked. We are on a well and his suspicison is that a little grit got in and blocked it.

I have attempted to do the same thing and the valve is totally clean but the water still does not flow into the toilet after i put it all back together. (yes it is on!) How do a reset the water pressure or whatever is at issue so it will flow into the toilet?

Thanks much.

The thing disassembles fairly easily. The rubber component can be replaced without replacing the whole thing.

Ah, thank you. I hadn't cleaned the filter bit. However, the issue remains that even reassembled no water flows into the toilet. I'm wondering if there is something i need to do to unblock?

Have you checked the supply tube leading to the fill valve?

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Thank you kindly, sir. That was it. Soon as water pressure hit it refused to play nicely. Appreciate the help.