No Flow Light On Salt Water Chlorinator

No Flow Light On Salt Water Chlorinator - How Do I Fix It?

Salt water chlorinators produce the chlorine needed to sanitise the water in salt water pools. These machines can be fairly complex, so what does it mean if you receive a message on your unit that says “no water flow, chlorinator on standby”?

In this article we will cover the various causes of insufficient water flow through your salt water chlorinator as well as how you may be able to remedy this issue at home.

Why Is My Salt Water Chlorinator “No Flow” Light On?

If the no flow light on your salt water chlorinator is lit up, it means that there is not enough water passing through your salt cell in order for your salt water chlorine generator to perform electrolysis.

This is important because electrolysis is the way through which the machine turns salt compounds into free chlorine molecules that acts as your pool’s sanitizer.

If your salt cell is not receiving enough water flow, there is an increased risk of electrocution, fire, and machine damage occurring. In these cases, the no flow light will turn on and your salt water chlorinator will cease to perform electrolysis until the issue with water flow is resolved.

Below we have assembled a list of steps you can take to restore flow to your salt cell.

How To Fix No Flow Light On Salt Water Chlorinator

Empty Skimmer Baskets & Check Pump Operation

Full skimmer baskets greatly reduce the amount of water that your pump system can pull in. Empty all skimmer baskets in your pool.

Afterwards, check the housing where the skimmer basket is installed to make sure debris has not overflowed into the water intake port. Debris is not intended to be in this area, so it can greatly reduce waterflow.

If your pump or filter has a pump basket attached to it where it sorts out other sizes of debris, you should also check this unit to see if it needs to be emptied.

Confirm that your pump is operating as normal.

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Clean Filter

Filters that become full of debris are likely to prevent adequate amounts of water from flowing through your chlorinator system.

Always shut the pump system off entirely before attempting to access the filter unit. If you have a cartridge filter, remove these cartridges and rinse them thoroughly.

If you have a sand or diatomaceous earth filter, use the backwash setting on your pump until the filter is thoroughly cleaned.

If you cannot get your filter reasonably clean by rinsing or backwashing it, it may be time to replace your filter media.

Check For Leaks

Check your pool’s pump system and plumbing for leaks. These could be areas where water is escaping, or may be areas where air is being entrained into the water lines.

If you notice any leaks in your pool’s plumbing, you may be able to patch it up temporarily using an at-home repair kit, but we recommend that you contact a professional pool servicing team as soon as possible.

Leaks that are not fixed can often become worse at rapid rates, and may also allow water into areas where it is not supposed to be, thereby weakening your pool’s overall foundation.

Replace Salt Cell

If you have tried all of the steps above with no positive results, you may have a damaged salt cell that is showing the no flow light incorrectly.

It might also simply be that your salt cell has reached the end of its life.

We recommend getting a second opinion from a professional in this type of situation so that you avoid purchasing replacement parts that are not needed.

Louis from Pool Advisor


A chemical engineer by trade, Louis is committed to debunking myths in the pool industry by explaining the underlying chemistry and making it accessible to all.