NJPools.club Community

Hey y'all—fellow Texan here with a gunite pool. I had the same panic last winter when my Intellichlor went totally dark! Turns out it's a built-in safety feature. Pentair units are designed to shut off automatically when water temps drop below a certain point (usually around 52–60°F depending on the model) to protect the cell from damage. It should fire back up once things warm up. I'd double-check your manual, but if it's around 55°F where you are, that's almost certainly all it is. No need to call a tech yet—just keep an eye on the temp.

**SlideStar is spot-on about the temperature cutoff**, but let's optimize your diagnostic approach. First, verify the actual water temperature with a calibrated thermometer—don't rely on ambient readings. Second, even in shutdown mode, you should confirm the power supply is intact. Check the breaker and the transformer for proper voltage output (should be ~24V AC). If the unit is truly dead with power present, the PCB might have a fault. I'd also recommend cleaning the cell if you haven't recently—scale buildup can cause erratic behavior. Document everything; data is key.

Ugh, I feel this—came home from my night shift last week to a dark Intellichlor and almost lost it. Steve's advice is solid, but honestly, if it's hitting 55°F at night in Texas right now, it's almost definitely the temp cutoff. Mine did the same thing. It's annoying because the manual doesn't scream about it, but it's normal. Just wait for a warmer day and see if the lights come back. If they don't, *then* start worrying about power or a board issue. Save your money and sleep first.

Pete's right—the manual buries that temp detail. I keep a sticky note on my panel now as a reminder. Also, if you're eager to test it, you can try pouring a bucket of warm water near the cell intake (not hot!) to see if it briefly wakes up. But really, give it a sunny day or two. Last thing: make sure your filter pump is running enough hours; if the flow switch isn't engaged, that'll keep it dark too. Hope it's just the cold!

Adding to the flow point: **ensure the flow switch is not stuck**. Debris in the system can cause false shutdowns. If you're technically inclined, you can bypass the temp sensor temporarily for a test (refer to wiring diagram), but I'd only advise that if you're comfortable with low-voltage work. Otherwise, monitor and log daily temps and unit status. If it persists above 60°F, consider a professional inspection. Prevention tip: install a pool thermometer with an alert for low temps next season.