The pressure tank is a key component of a well system that protects the well pump and maintains stable water pressure throughout the home. However, too often pressure tanks go years without being checked or adjusted. This can cause inconsistent water pressure and unnecessary stress on the well pump.
This article walks through a procedure to monitor and tune this critical system component. A case study is presented alongside the procedure. It is recommended to check this annually, but the imbrr well monitoring system makes it easy to continuously check the performance as we’ll discuss below.
System Overview
Where can I find the pressure tank and switch? See below for a labeled diagram of a typical well system with a submersible pump. Your system may look slightly different, but the general components are often the same.
Step 1: Observe Pump Cycles
After identifying the components, the first step is to observe pump performance over a few days. Document the following:
- Minimum Cycle Volume
- Minimum Run Time
- Pressure Switch Start and Stop
This can be viewed in the imbrr dashboard under pump performance. Click “View Last 7 Days” to see the pump history. See below from our case study:
For this example, the minimum cycle volume is 5.6 gallons in 34 seconds with an average start pressure of 43.8 PSI and stop pressure of 59.3 PSI.
Step 2: Adjust Pressure Switch
Safety First: power must be disconnected (typically pump breaker) before any adjustments are made to the pressure switch.
The factory settings and instructions for adjustment are typically found on the plastic cover. See below from our case study system:
With the above guidance, the pressure switch was adjusted to 40/60 PSI by turning nut #1 counterclockwise 1.5 turns and nut #2 clockwise 2 turns. The effect is shown below:
Step 3: Adjust Tank Air Pressure
A Schrader valve is typically located on the tank to add or remove air. The easiest way to determine a need for adjustment is to review the expected drawdown for your tank. It should generally be between 25% to 30% of the tank capacity. In our case, the pressure tank is a Water Worker 32 gallon HT-32B which has a documented drawdown of 8.57 gallons at 40/60 PSI (MC#7230 01/16):
We are a little low (7.8 gal vs 8.57 gal) so the tank was drained and air pressure was measured to be 36 PSI. The recommended air pressure is 2 PSI below the ON pressure as shown in the below table:
| Pressure Switch ON (PSI) | Drained Tank Air Pressure (PSI) |
| 20 | 18 |
| 30 | 28 |
| 40 | 38 |
So in this case, a bike pump was used to increase the tank pressure to 38 PSI. This small addition of air resulted in a minimum drawdown of 8.4 gallons in 50 seconds, much closer to the documented volume.
Note, it is generally recommended to have a minimum run time of at least 1 minute to allow for proper pump cooling. Techniques to achieve this would be proper pressure tank / pump sizing (expensive on an already existing setup), or the pressure switch could be further adjusted to increase the drawdown. This customer wanted to keep the higher house pressure so the 50 second run time tradeoff was accepted.
Step 4: Set Alerts
To continuously monitor the pressure tank settings, alerts can be set on both the minimum cycle volume and pressure ON/OFF. 85% to 90% of the expected range is a good rule of thumb. The below was set for our example (note, the max cycle volume is for leak detection):
Wrap Up
Even though this system was last adjusted 3 years ago, both the pressure switch and tank pressure needed to be re-tuned resulting in a 50% improvement in the tank storage (5.6 gallon -> 8.4 gallons). This is a significant reduction in pump cycling, extending system life and reducing power consumption. The imbrr well monitoring system allows you to set alerts for continuous detection, avoiding the need to manually check the system.
Have feedback on this article or want to discuss your individual results? Please reach out to us at support@imbrr.com. We are happy to provide additional suggestions to solve your unique problem statements.