Residential Expansion Tank Pressure

Use a bicycle pump or compressor to fill the tank to match the system pressure you noted earlier.

Residential expansion tank pressure.

Most expansion tanks come pressurized to 12 40 psi but before you install the tank you have to match the system pressure. This is usually between 40 and 60 psi. For example if your well pump pressure control switch is set to cut in start pumping water from the well at 30 psi then set the pressure tank to 30 2 28 psi. This means that whoever installed your tank was supposed to manually increase the tank s pre charge to match the water pressure at the time of install.

Use an air gauge to check the pressure inside the tank. Use a tire gauge to check the pressure. If the pressure setting reads less than 12 psi it probably will since you drained water from the tank attach an air compressor or hand air pump to the air fitting connection and pump air into the expansion tank. The air pressure should be 12 psi pounds per square inch.

A water heater expansion tank can often be replaced without having to replace your entire system. Twelve psi is appropriate for systems where the top of the piping is about 16 feet above the inlet of the expansion tank assuming that 5 psi static pressure is desired at the very top of the system to allow air vents to function properly. You should also have a mechanism in place to check the pressure such as a water pressure gauge that can tell you if the tank is functioning properly or if the diaphragm has been damaged. The installer may check the air charge using an accurate gauge type pressure gauge and as we explain in this article series for taller buildings requiring a higher cold starting pressure in the boiler the expansion tank may need to be pre charged to that same pressure level a setting above 12 psi in which case your heating service technician may add a bit of air to the pressure tank through its normally sealed air valve.

Step 4 check to see if your release valve is spurting water. Bleed air pressure out of the water tank or add air pressure into the water tank until the tank pressure is at the desired set pressure. Find pressure tanks at lowe s today. Obtain a suitable thermal expansion tank based on the size of your water heater.

Read the pressure requirement on the side of the tank.