Your pool filter pressure gauge is central to troubleshooting many issues, from low water flow to pump malfunctions. Understanding how it works and how to recognize potential problems is critical for the longevity of your pump and filtration system. This guide will help you get acquainted with your pool filter pressure gauge and learn what unusual readings might indicate.
What is a pool filter pressure gauge?
A pool filter pressure gauge is the small dial on top of your filter that measures the water pressure inside the tank. Here are the basics of this essential accessory:
Key components of your pool filter pressure gauge
Every pool filter pressure gauge includes the following parts within a stainless steel housing:
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Dial face: Displays pressure readings in PSI (pounds per square inch). Some feature color-coded zones for quick assessments at a glance.
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Needle: Part of the dial face that moves in response to real-time pressure changes and indicates the pressure reading.
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Bourdon tube: Internal mechanism that expands and contracts as pressure fluctuates, turning the dial accordingly.
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Threaded connection: Screws directly into filter housing.
How does it work?
As your pump runs, it pulls water from the swimming pool into the tank, where it passes through your filter media (sand, cartridge, or DE), creating a certain degree of resistance. The gauge measures the pressure generated by that resistance as water moves through the pool filter.
What is a normal pool filter pressure?
While there’s no universal PSI target for all pool filter pressure gauges, most residential pools fall within the range of 10 to 20 PSI, with some consistently reading slightly higher or lower. To find the normal PSI for your system, check the pressure gauge immediately after cleaning or backwashing your filter.
Related: Pool Filter Maintenance 101: What Every Pool Owner Should Know
What does it mean if the pool filter pressure is too high?
When you notice a high reading on your pool filter gauge, act quickly to minimize strain on your pump and prevent water quality issues.
When is your pool filter pressure too high?
That reading you took after backwashing your filter indicated your clean baseline pressure. Once your pressure measures 8 to 10 PSI over that baseline, it’s time to take action.
Common causes of high pool filter pressure
A high reading on your pool filter pressure gauge may indicate an underlying issue with your filtration system, such as:
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Dirty or clogged filter: Dirt, debris, and small particles limit efficient water flow.
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Missed maintenance: Forgetting to backwash sand and DE filters increases resistance.
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Return line blockages: A blocked jet and closed return valve restrict water movement.
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Dirty or failing multiport valve: Caused by a worn gasket or internal obstruction.
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Oversized pump: Pairing a heavy-duty pump with a more modest filter can create consistently high readings.
How to troubleshoot when the pool filter pressure is too high
Start by comparing your standard baseline pressure to your current pressure reading. Once you’ve confirmed that your PSI is too high, clean and backwash your filter (if appropriate), then take another reading.
If it’s still too high, check return valves and the inside of your filter for blockages. Then, inspect the pressure gauge for potential malfunctions. To test the gauge, turn off the pump, release the pressure, and ensure the dial reading is zero. If that doesn’t work, it may be time for a replacement.
Related: How To Clean a Pool Filter the Right Way
What does it mean if the pool filter pressure is too low?
While a high pressure reading signals a blockage in the filter, a low pressure reading indicates an issue with the suction side of your system. If left unaddressed, it could lead to poor circulation, cloudy water, and ineffective chemical distribution.
When is your pool filter pressure too low?
Your pool filter pressure is too low when the gauge reads 5+ PSI below your average baseline. So, if your pressure typically measures 20 PSI, a reading of 15 PSI should raise an alarm.
Common causes of low pool filter pressure
As with pressure readings that are too high, low pool filter pressure may be caused by a number of factors, including:
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Low water level: Air enters the pump when water drops below the skimmer opening.
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Clogged pump basket or skimmer basket: Debris stops water from reaching the pump.
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Air leak in the suction line: Caused by cracks, damaged plugs, and loose fittings.
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Partially closed suction valve: Leads to reduced water flow.
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Clogged or damaged pump impeller: Inhibits adequate circulation.
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Faulty pressure gauge: Possible if the needle sticks or the gauge doesn’t return to zero when the system is off.
How to fix low pool filter pressure
To troubleshoot a lower pressure reading, assess your water level and clear any debris from your baskets. This is a good time to restart your system and check the reading. If needed, inspect your pump basket for air bubbles and cracks, ensure valves are completely open, and remove debris from the impeller. Then, take another reading.
Related: How To Change Sand in a Pool Filter
Call the pros at GPS Pools for all your filter repair and replacement needs!
A functional pool filter pressure gauge is essential for in-ground and above-ground performance. Whether your system is from Hayward, Pentair, or another brand, GPS Pools is happy to inspect and service your unit to ensure optimal performance. Schedule your visit today!