Do you mean your replacing the pump that provides water to your heat pump?
If so, tell me what pump it is. The horse power, pump model and the depth to water in your well.
With a ground water heat pump, the unit usually uses much less water than the pump can provide. This cycles the pump constantly while the unit is running. To prevent this you can go with a small 40 gallon tank and the Smart Tee. This will make your pump last a lot longer.