No Flow
Pentair Pool Equipment
Severity: CriticalWhat Does This Error Mean?
No Flow means the equipment detected that water is not flowing through the system. The pump may be off, the filter may be clogged, or the flow sensor is faulty. Check the pump, clean the filter, and inspect the flow switch.
Affected Models
- Pentair IntelliChlor
- Pentair MasterTemp Heater
- Pentair IntelliFlo Pump
Common Causes
- Pool pump not running
- Filter dirty — restricting flow
- Skimmer basket or pump basket clogged with debris
- Flow switch stuck or faulty
- Air lock in the pump preventing proper flow
- Valve partially closed
How to Fix It
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Make sure the pool pump is running.
The salt system and heater only operate when the pump is on. Check the pump and timer.
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Clean the skimmer basket and pump strainer basket.
Clogged baskets restrict water flow. Empty leaves and debris from both baskets.
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Check the filter pressure gauge.
If pressure is 8-10 psi above the clean starting pressure, the filter needs cleaning. Backwash (sand/DE) or clean the cartridge.
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Check the flow switch.
The flow switch is a small sensor in the plumbing. It can get stuck with debris. Gently tap or clean it.
Frequently Asked Questions
What is the flow switch?
A flow switch detects whether water is flowing through the pipes. It prevents the heater from firing without water flow (which would damage it) and tells the salt system to stop generating when there is no flow.
Can I bypass the flow switch?
Not recommended. The flow switch is a safety device that prevents equipment damage. Fix or replace the switch rather than bypassing it.