Learn More About Water Pressure
For those depending on a pump system to deliver water from a well or to boost water pressure, a loss of water pressure can indicate an electrical short or pump malfunction. The problem sometimes lies with the pump pressure control switch, which turns the water pump on when it detects a drop in pressure. An electrical surge or lightning strike can cause a blown fuse or circuit, shutting off power to the pump. In extreme cases, damage to the pump itself requires replacement or repair of the damaged parts. Please contact a plumber for repair.
Clogged pipes are usually characterized by a steady, standard water flow that then slows when the faucet is left on for a period of time. Older homes frequently experience blockages in the supply water pipes. Mineral deposits or debris build up over the years or break free and reduce the water supply.
Homeowners who utilize a water softener might experience decreased water pressure if the water softener malfunctions. If the water meter valve or the house valve is not fully opened or completely closed, the house will have little to no water pressure. Additionally, a malfunction of the water pressure regulator installed in some homes can cause intermittent or constant decreases in water pressure.
Wear & Tear
As pipes and faucets age, normal wear and tear can lead to decreased water pressure. Low water pressure in a single faucet or shower head might result from clogs or rust in the aerator. Cleaning or replacing the aerator should restore normal water pressure to the faucet. Years of mineral buildup resulting from hard water can reduce the volume of water able to flow through the home's pipes. Also, a worn out water heater might result in decreased water pressure when running hot water.
Whole House Low Water Pressure
If every fixture in the house has low water pressure, the cause may be corroded piping, a restriction of the line due to a failed pressure regulating valve (PRV) or backflow preventer, low municipal water flow, or a valve partially closed.
How to Test Your Water Pressure
Most home improvement stores sell a hose bib water pressure gauge. These are simple to use. Make sure no water is running elsewhere in the home. Thread the pressure gauge onto any hose bib, and turn on the bib. Write down the resulting pressure reading. It is your "static water pressure." Municipalities may supply water pressure from 20 to over 100 PSI, but a typical pressure regulator is set between 50 to 75 PSI. If your water pressure is above 40 PSI, your "low water pressure" problem is not a water pressure problem, but a problem with the flow of water through your plumbing system. If you have a pressure regulating valve (PRV), you can adjust the PRV by turning the hex head bolt at the top of the bell clockwise and observing if the pressure is increased.
Partially Closed Valves
Verify that the shut off valve on the main water supply is fully open. Shut off valves are usually located where the plumbing enters the home. There are two basic types: the ball valve configuration and the gate valve configuration.
The ball valve usually has a handle similar to the image, where the long portion of the handle indicates the position of the ball diverter inside. When the handle is "in-line" with the piping, as shown in the photo, water can flow freely. Turning the handle 90 degrees shuts off the water entirely. Any position in-between restricts flow.
A gate valve, and its cousins that look similar such as globe valves, use a rotary handle to determine the position of the "gate" inside. Turning the valve handle to the right (clockwise) closes the gate, preventing water flow. Turning the valve handle to the left (counter-clockwise) opens the gate completely. Older valves may be stiff and seem frozen. Under the handle is the packing nut; using a wrench on it and turning it 1/8 turn, just barely loosening it, is often all that's needed to "unfreeze" the handle.
Where Else Valves Will Be
If all the hot water seems to have a low flow situation, check the cold water inlet to the water heater; it should also have one of these valves. In some older homes, you may have multiple valves as plumbing has been reconfigured.
Replacing Pressure Regulators
A pressure regulator is a water device shaped like a bell. The regulator is usually found below the hose connection in the front of your home or in the garage, though it may be located in a different area depending upon the construction of your home. If the pressure regulator goes bad or stops working, it may cause low or high water pressure in some or all of the water fixtures in your home. Regulators typically have a lifespan of 10-plus years. If you are uncomfortable making the repair yourself, please call a plumber.