Pool salt cell not generating chlorine
moderate 45–90 min
Tools: salt test strips or a digital salt meter, bucket, garden hose, rubber gloves and eye protection, plastic scraper · Materials: muriatic acid (or a commercial cell-cleaning solution), pool salt if the reading is low
Steps
- Read the control box first: a 'low salt' or 'check cell' light points at chemistry or scale, a blank or flashing box points at power or the board.
- Test the salt level with strips or a meter, not the box's own reading; if it is below the maker's range (usually 2,700–3,400 ppm) add salt by the bag and let it dissolve for 24 hours.
- Turn the power off at the breaker, unscrew the cell unions, and look through it: white crust between the plates is calcium scale.
- Stand the cell in a bucket of 4 parts water to 1 part muriatic acid — acid into water, never the reverse — for 15 minutes or until it stops fizzing, then rinse well.
- Refit the cell, restore power, and set the output to 100 % for a day; retest free chlorine after 24 hours.
- Check the water balance: pH above 7.8 or high calcium hardness will scale the cell again within weeks.
Stop and call a pro if
- the plates are worn thin, warped or flaking after cleaning — the cell is at the end of its life
- the control board shows an error that cleaning does not clear, or trips the breaker
- chlorine still reads zero after cleaning and correct salt for 48 hours
What a pro does that you can't
A pool technician tests the cell's output amperage, replaces a spent cell or flow sensor, and diagnoses the control board rather than replacing the whole chlorinator.
DIY cost: $10–25 in acid and test strips; $40–60 for a bag of salt