Whistling continues after multiple removals and system flushes. Whistling started after seal replacement (curing a valve not closing problem). Any suggestions.

Hi Safetyguy

It could be an issue with the shut off under the toilet tank. First, check to be sure the shut off valve is fully opened (open and close to be sure). If that isn't the issue, you may want to remove the guts to the shutoff under the toilet tank and may need to replace the washer or the entire shut off to resolve the issue.

If the shut off is not the problem and you have messed with the fill valve a number of times then replacing the entire fill valve may be required (super fast, easy job).

Let me know what you think, OK?

Mark