If you use water from a well and the current water pressure is low or you would like to increase it especially if you have a sprinkler system, you will need to adjust the pressure switch’s cut-in and cut-off pressure.
A pressure switch is the little device near the pressure tank that is responsible for turning the well pump on and off. It does so by detecting the pressure of water in the pressure tank ensuring you have sufficient water pressure in your house.
Pressure switches have 2 pressure settings, the cut-in and the cut-off pressure. The cut-in pressure is the lower pressure settings when the pressure switch triggers the pump to kick in, while the cut off pressure is the higher pressure setting when the switch turns the pump off.
There is usually a 20 psi difference between the cut-in and the cut-off pressure. If the cut-in pressure of the pressure switch is 40 psi the cut-off pressure will be 60 psi. The pressure factory settings of the switch are also found under its cover.
To adjust the cut-in and cut-off pressure of your pressure switch, turn off power to pump and remove the switch’s cover. Using a wrench, tighten the nut on the big spring to increase the pressure, or loosen it to reduce the pressure. Each turn produces about 2-3 psi change in pressure.
The small spring only changes the pressure difference. This means tightening or loosening the nut will only change the cut-off pressure.
It is important for you to remember that you should also adjust the pressure of the pressure tank after adjusting the cut-in and cut-off pressures of the pressure switch. Ideally, the pressure of the tank should be 2 psi lower that the cut-in pressure.
This means that if you changed the cut in pressure from 30 to 40 psi, you will need to adjust the pressure of the tank from 28 to 38 psi. Failing to do so will greatly reduce your pressure tank’s drawdown.
How to Adjust your Pressure Switch
Adjusting a pressure switch is very easy and every homeowner who uses water from a well should know how to do it. The only thing you should remember to do is to work safely by turning off power any time you are working on the pressure switch.
The following are the steps to follow when adjusting a pressure switch:
1. Determine Current Cut-in and Cut-Off Pressure
In order to adjust your pressure tank, you must know your present cut-in and cut-off pressure and what you need to adjust it to. As I said before, the pressure settings will be found underneath the pressure switch’s cover but you can also determine it on your own.
Here is how to check your current cut-in and cut-off pressure:
- Turn on the the nearest faucet.
- Keep your eyes on the pressure gauge near the pressure tank (usually on the manifold at the bottom of the tank).
- Notice the pressure when the pump kicks in. That is your cut-in pressure.
- Turn off the faucet.
- Let the tank fill with water and again notice the pressure when the pump goes off. That is the pressure switch’s cut off pressure.
Usually, you should have a 20 psi difference between the cut-in and the cut-off pressure. If it is more or less than that, you will need to adjust the pressure differential as well. More on that later in this post.
2. Turn off Power to the Pressure Switch
There are lots of naked wires on the pressure switch. You should never attempt to adjust the pressure switch while it is still powered. Not only are you putting yourself at risk, but kids, pets may come over while you are working, which subjects them to serious risks.
Turn off power to your pressure and unplug it from the electrical outlet. This will be repetitive since you will have to keep turning the power on and off as you do the adjustments but it is the correct way to do it.
3. Adjust the Cut-in and Cut-off Pressures
- The pressure switch cover is usually attached using a nut or screwdriver. Remove the cover and put it aside.
- With the cover out, you will see 2 springs compressed on bolts using nuts. There will be a big and a small spring. The big spring is what is used to adjust both the cut-in and cut-off pressure.
- To increase the cut-in and cut-off pressure, use a wrench to turn the nut on the big spring clockwise (tighten it). This will compress the spring more.
- If you want to reduce the cut-in and cut-off pressure, turn the nut counterclockwise (loosen it).
Note: One complete turn results in a 2-3 psi change in the cut-in and cut off pressure. If you therefore want to increase the cut-in and cut-off pressure by 10 psi, you will need to turn the nut about 3.5 turns.
- To check if you have your desire pressure switch settings, place the cover on the pressure switch and turn on power to the pump/pressure switch.
- Open a nearby faucet and again check the new cut-in pressure of the pump.
- If you are yet to get your desired cut-in pressure, turn off the pump and make more adjustments.
- Repeat the above procedures till you finally get your preferred pressure switch cut-in and cut-off pressure.
4. Adjust the Pressure Differential (Optional)
Pressure differential refers to the difference between the cut-in and cut-off pressure. As I have already said that figure should be 20 psi but you can also alter it if you so wish.
Just like when adjusting the cut-in and cut-off pressure, you will need to have power to your pressure switch turned off. Turn the nut on the small spring clockwise to increase the cut-off pressure or counterclockwise to reduce the cut-off pressure.
Note: If you adjust the cut-off pressure to a setting that the pump cannot achieve, you will notice that your pump will run continuously without turning off. What you need to do in that case is to turn the pump off and adjust the cut-off pressure to a lower setting.
5. Adjust the Well Tank Pressure
After adjusting the pressure switch’s cut-in and cut-off pressure you also need to adjust your pressure tank as well. Remember that the top half of your pressure tank is an air chamber which is compressed by the water in the bladder to achieve water pressure.
As I had mentioned earlier, the pressure tank should be at 2 psi lower than the pressure switch’s cut-in pressure. You will therefore need to check the air pressure in the pressure tank and then adjust it to reflect the new pressure switch settings.
The problem is that you will first need to drain the tank. Checking the pressure with the pressure tank full of water will give you the water pressure but not the pressure in the air chamber.
Here is how you adjust the pressure tank:
- Turn off power to the well pump.
- Check if there is shut of valve between the pressure tank and the plumbing to your house. Turn it off.
- Connect a garden hose on the drain valve at the bottom of the pressure tank and turn on the valve. Let the tank drain out completely.
Note: If there is no shut off valve between your pressure tank and the house plumbing, you will need to drain the pressure tank from one of the faucets. Just remember to turn off or divert water filtration equipment to prevent clogging them up with sediment.
- Remove the air-inlet cap at the top of the pressure tank and connect a tire/pressure gauge. Check the pressure reading on the gauge.
- Use and air compressor or even a bicycle pump to add more pressure to the tank if your adjust the pressure switch settings upwards. If you reduced your cut-in and cut-off pressure, you will need to bleed off pressure from the tank by pressing the piston down.
- Once you have adjusted the pressure tank’s pressure turn off the drain valve and turn on power to the pump. Open the shut off valve to the house as well.
And basically that is how to adjust your well’s pressure switch and pressure tank. I hope you found this guide to be helpful.
Related post: How to replace a pressure switch.