Plumbing in the Home/change in water temp


QUESTION: If I were to take a shower downstairs and someone were to use the hot water elsewere the water temp drops with a noticable decrease in water pressure. How can this be corrected?

ANSWER: Hello,
There are several ways to correct this problem. I do not know if you are on a well system so the simplest solution there is to up the pressure. On a public system, if you have a pressure regulator on the incoming water you can adjust that. If you have neither, meaning public water and no regulator,  you can install pressure regulating faucets that also control temperature. Sometimes called scald guard faucets, they sense pressure changes and adjust flow between cold and hot to prevent a hot or cold blast of water when water is used somewhere else in the house.
Another fix is to install flow restrictors in the shower head and faucet spouts to cut down on the gal/min flow. These are small discs that install in the aerator with smaller orifices.

---------- FOLLOW-UP ----------

QUESTION: I am not on a well.  The house is 20 yrs old. The water pressure @ the house is 70psi. At the dowm stairs with no other water running is 70psi.When the hot water shower upstairs is turned on the downstairs water pressure drops to 20psi and gets sooooo cold. Do the latter recommendations still hold the solution?

Ok then the next thing to check is whether or not you hav a pressure regulator on the main  by your meter. 70 psi is rather high for most systems.  Also check to seeif there is an inline check valve, these sometimes allow water to squeak  by when there is no flow and then pressurize the lines , when a faucet is turned on they do not open . If there is a regulator , chances are it's shot. I am curious as to where your gauges are located. Also have you contacted your water supplier?  They could test your meter and regulator in most cases.
A regulator will sometimes let water by and not fully open as well

Plumbing in the Home

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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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