Originally Posted By: tgardner
This post was automatically imported from our archived forum.
Because your pump is a booster, you will need to reset the tank precharge pressure to match the system pressure in your house. Here is the procedure:
All water system tanks are precharged at the factory. All 8 and 11 inch diameter tanks are precharged at 18 psig. The 15
inch diameter tanks are precharged at 28 psig while the 22 and 26 inch diameter tanks are precharged to 38 psig. The
final precharge pressure should always be 2 to 3 psig below the cut-in (pump turns on) pressure of the pressure switch.
Release air or add air as required using the following procedure.
1. Determine the pump cut-in pressure setting. The pressure switch should have this information located on/in the
2. With no water in the tank, measure the precharge of the water system tank using an accurate pressure gauge at the
air valve (similar to an auto tire gauge).
3. Release air or add air to the tank to make the pressure in the tank 2 to 3 psig LESS than the pump cut-in pressure
If the system pressure is higher than the originalcut-in pressure of the pump pressure switch,(as may be the case at your house) the pump installer may have adjusted the switch without re-setting the precharge, which would cause short-cycling.
If the tank is a small 8" dia tank then the pump will start after about 1/2 gallon of water is released from the system. This would appear as short-cycling
If the tank is a small 11" dia tank then the pump will start after about 1&1/2 gallon of water is released from the system. This would be in about 30 seconds with a standard faucet at 3gpm.
Good luck, tg