What causes low water pressure?
How do you currently get water? From the city / your well system
--> If you receive water from the city, the water works is obligated to meet only a minimum pressure criteria, for e.g. some cities do not supply water at a
pressure higher than 20 to 30 PSI recorded at the water meter. If your water meter is located far away from the house, a further pressure drop occurs by
the time the water reaches the house.
If you have a well pump with a pressure switch, the pump is set to deliver pressure between a range of pressure, for e.g. 30 to 50 PSI or 40 to 60 PSI.
When a shower is turned on in the house, the initial pressure is 60 PSI but as more fixtures are turned on, the pressure starts dropping, resulting in an
inconsistent shower pressure.
What is the size / material of the incoming line?
--> The pipe line size determines how many gallons per minute of water will flow through it. The smaller the pipe size, the lower the amount of water
volume flowing through it and vice versa. Typically, a 3/4" pipe can allow approximately 15 GPM flow, 1" allows upto 25 GPM flow, 1 1/4" allows upto 40
GPM flow. It is necessary to have adequate water volume to support the demand from all the fixtures in the house. If the demand from the shower,
kitchen sink, dish washer, washing machine etc. exceeds the amount of water being supplied by the city/well, there will be poor pressure on account of
low water volume.
Pipe material is also important because, some pipe materials such as galvanized pipe get corroded due to reaction with chemicals in water that are
meant for purification. However, corrosion causes deposition of oxidized metal inside the pipe reducing the water ways. The reduced water ways cause
a restriction in the flow of water, thus reducing water volume. As mentioned above, reduced water volume directly affects water pressure.
What is the current incoming pressure from the city/well?
--> To accurately measure the incoming pressure, it should be measured at operating conditions:
Static pressure: Pressure measured at or near the water meter when there is no water flow in the house.
Residual pressure: Pressure measured at or near the water meter when water is being used in the house.
The static pressure is usually slightly higher than the residual pressure. However, a large difference between static and residual pressure indicates
that incoming water volume must be low.
If the residual pressure is known, we can determine how much pressure boost is needed to bring the pressure up adequately. This information helps
immensely in selecting the appropriate booster pump system.
Are you at the end of the line from the city or community well?
--> If your house is at the end of the water line from the city or community well, at peak water use periods, when all the people sharing your water line
are using water, you may be left with minimal water volume and pressure. In some cases, water storage may be necessary.
How many showers, sinks, appliances etc. do you have in your house?
--> Counting the number of fixtures in the house is important in analyzing whether your incoming pipe line size, incoming pressure and incoming
volume are sufficiently sized to cater to the maximum water demand that may be generated in the house.
Do you have an irrigation/sprinkler system ? If yes, how many heads do you have on the largest zone?
--> Typically an irrigation/sprinkler system is divided into multiple zones and each zone has a number of heads and one zone turns on at a time. If this is
the case, we only need to count the heads on the largest zone in the irrigation/sprinkler system to determine the maximum flow requirement and verify it
against available pipe size, incoming pressure and GPM.
It is also advisable to operate the irrigation system during off-peak usage period in the house so as to ensure adequate water volume availability for
Once all the information is verified, the task of selecting a booster pump to increase the water pressure is simplified greatly. Now it is of prime
importance to consider a robustly built automatic system that will be energy efficient, easy to install, quiet in operation and compact in design. At Towle
Whitney LLC, we staff master plumbers and engineers to design water pressure booster systems to perfectly suit your needs.
For further information on Towle Whitney water pressure booster pump systems, click here.