Plumbing in the Home/fluttering toilet valve


QUESTION: The fill valve on my hall toilet flutters, filling in rapid spurts even though the toilet has not been used nor is it leaking into the bowl.  I turned on the adjacent shower and it did the same thing several times in a row.  It does this at odd times and not always.

ANSWER: Bill, It sounds like an incoming water pressure problem. If that's the case then a regulator may have to be installed on the line. Another problem solver for this would be to install a pressure tank in the cold line to more or less cushion the erratic pressure spikes.I would do this before installing a regulator. The reason your seeing this at the toilet is because  the ball cock is the weakest link and is easily affected by pressure changes.

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QUESTION: Erratic pressure makes sense, not familiar with pressure tanks. Can I purchase one at the store ? Can you describe what it looks like. Is the cause most likely from my water company's lines or should I explore my lines. The original portion of my home is 1960's and on a slab but an addition was added in '96. The county water supplies my built in pool first and it appears the lines have been reconfigured over time.  Could air be getting in without my knowledge and causing this?

Bill, The tank is a bladder style expansion tank that is piped in to the cold water line,usually between the main shut off and the water heater. It really doesn't matter as long at it is  on the cold water supply line. What is normally done is a tee with a female threaded adapter is cut into the line and then the tank, which is 1/2" threaded inlet, is screwed into the tee. This will absorb pressure fluctuations and stop the ballcock from being force to open.

An ST-5 will do the job.

Air is not the issue here. Air only effects closed systems like boiler systems and such.

Domestic public water is an open system

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Jay Nicholas


Plumbing & Heating (warm air, hot water & steam heat)


40 years in the business, 35 years as a lic. master plumber in NY State. Retired

Graduated Magna cum laude at the School of Hard Knocks

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Commercial, residential and light industrial. You name it ...I have probably worked on it

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