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Pool Pump Timer Not Working? Here’s Why (+ How to Fix)

A working pool pump timer is essential. If the pump isn’t running enough, you’re at risk of algae blooms, cloudy water, and other sanitary issues. And if it’s running too often, you could wear out the motor and have to replace the pump.

That’s why you need to make sure your timer is working properly – and fix it quickly if it isn’t.

If your pool pump timer isn’t working, it’s likely because of these explanations:

  • Broken timer motor
  • Power outage
  • Circuit breaker problems
  • Loose timer tags
  • Disconnected wires
  • Incorrect time of day
  • Broken internal timer

In this article, I’ll discuss several reasons your pump’s timer won’t work. I’ll also explain how you can fix each problem with simple step-by-step instructions. Let’s get started.

Worn Timer Motor

If your timer’s motor is old or broken, it won’t work. This is the most common cause of a pump not working.

The good news is that these electromechanical pool timers typically last well over a decade.

If the motor is old, I suggest contacting the company if it’s within the warranty replacement period. The timer should last longer than the motor in most cases.

Water damage, overheating, loose wires, and long-term usage expedite the wear and tear. Unfortunately, the only solution to a worn timer motor is to get a new timer. I’ll explain the replacement process below.

How to Fix

Here’s how you can replace a broken timer:

  1. Turn off the power at the circuit breaker to prevent electrical shocks.
  2. Switch the tab to the OFF setting at the bottom of the timer.
  3. Remove the line, load, and grounding wires from the timer, then unscrew the timer from its box.
  4. Remove the rear wires connecting the timer to the circuit breaker, but leave the wires connected to the breaker.
  5. Place the Intermatic T104 Electromechanical Timer in the old timer box and wire it to the breaker.
  6. This timer has a line and load labeled section, letting you know where to place the old wires for the pump motor.
  7. Turn on the circuit breaker, then place the timer tags on the clock at the time you want it to start and stop (the previously mentioned timer includes multiple tags).
  8. Pull the clock outward, then rotate it until you set it to the current time.
  9. Flip the bottom tab to the ON setting to start the clock.
Intermatic T104 Electromechanical Timer

Power Outage

Power outages can stop the pool timer’s clock from spinning. When the power comes back, the timer will be at the same setting and time as when the power outage happened. You’ll have to reset the clock to get it back on track.

How to Fix

If there’s a power outage, reset the clock by pulling it toward you and rotating it until it’s at the current time. Every pool pump timer has a tab that shows where the clock’s current time is. (Most of them have silver or gold tabs).

Make sure the breaker isn’t tripped before setting the clock. If it is, flip off the breaker, turn it back on, then make the necessary adjustments.

Tripped Circuit Breaker

There are many reasons why a pump’s circuit breaker trips. Let’s review the reasons here:

  • Overheated pump motors, heaters, salt systems, and pool vacuums
  • Power outages
  • Overloaded circuit breakers with too many amps
  • An old circuit breaker that needs to be replaced
  • Water entering the motor

A tripped breaker should be addressed immediately, as it’s a sign of an electrical problem.

Failure to diagnose the issue could worsen the circuit breaker and damage the timer, the breaker, or the pump’s motor.

How to Fix

Follow this process to find the necessary solution:

  1. Figure out what tripped the breaker. The pump’s motor shouldn’t be hot, so hovering your hand over it would be a clear indicator. Furthermore, there shouldn’t be water in the motor. Make sure there aren’t too many devices plugged into the same breaker.
  2. Replace the motor if it keeps tripping the breaker. Don’t forget to check if the wires are loose. Loose wires can trip the breaker, even if the pump is in good condition. Tighten the wires to the old pump before getting a new one.

For a more in-depth explanation of how to fix this issue, follow my guide on how to fix a pool pump that keeps tripping the breaker.

Loose Timer Trippers

Timer trippers keep the clock on track. Without them, the pump would run indefinitely.

Loose timer trippers prevent the pump from knowing when to start or stop, rendering the clock useless. You might hear a ticking sound, but the timer won’t do anything to the pump.

How to Fix

Tighten the timer trippers to prevent them from sliding around. If they’re stripped, it’s time to get new ones.

If you need to replace stripped trippers, my go-to are the Intermatic Time Switch Trippers. You’ll receive four ON and four OFF tags, providing plenty of spares.

To install, twist off the old tags and slide the new ones in their place, then tighten the screws on the desired on and off times.

Intermatic 156T1978A Time Switch Trippers for T100 Series

The timer’s clock is rarely stripped because the metal is durable. However, you can adjust the clock by five minutes in either direction to avoid slipping tags. I recommend replacing the clock if it’s scraped and can’t support the tags.

Pro-tip: Make sure your tags are designed for the clock. There are countless tags for countless clocks, so it’s easy to confuse them with one another.

Disconnected Wires

There should be wires connected to the timer and the pump motor. The timer should also be wired into a circuit breaker, providing surge protection. If any of these wires are loose or disconnected, the pump’s timer won’t work.

The wires can loosen from long-term usage, rough movements, pump vibrations, and more. They also might have been installed incorrectly or weren’t tightened properly.

How to Fix

To inspect and repair the wires, follow these steps:

  1. Turn off the power at the circuit breaker (if you fix the breaker wires, turn off the main house power).
  2. Loosen the wires from the breaker, then check if they’re damaged.
  3. Trim the wires and twist or crimp the ends, then push them into the breaker’s wire nodes and tighten them.
  4. Loosen the wires from the back of the pool pump’s timer between the timer and the breaker, then perform the same method as step 3.
  5. Do the same steps as steps 2 and 3 for the pool pump timer going between the timer and the pump.
  6. Tighten the pump’s wires sitting in the motor housing.
  7. Turn on the circuit breaker and check if the timer works.

Incorrect Time of Day

Improper installation will leave a pump’s timer set to AM instead of PM (or vice versa).

If your pump is set between 12 AM to 7 AM, you might not know it works. Switching the clock will put it from 12 PM to 7 PM, which is the typical running time.

Pro-tip: Your swimming pool pump should run when it’s the warmest outside. The sun’s heat increases the chances of an algae bloom, and you want your water circulating during that time of increased risk.

How to Fix

It’s easy to mix up the times, especially since pool pump timers use small fonts. Try this quick trick:

  • Remove the timer trippers from the clock.
  • Pull the clock outward, then rotate it until the correct time is lined up with the current time tag (it’s usually a silver or gold pointer on top of the clock).
  • Attach the timer trippers for the desired ON and OFF times.
  • Turn on the clock if it’s off, then let it run as usual.

Broken Internal Pump Timer

An internal pump timer lets you set the clock digitally. You can choose the speed, start time, and finish time.

Unfortunately, all of these settings come with room for error. Incorrect adjustments, mechanical errors, and programming issues can prevent your pump’s internal timer from working.

Keep in mind that you won’t have an internal clock if you have an external timer.

How to Fix

If your pump has an internal timer (a digital model), follow this process:

  1. Choose the SETTINGS menu.
  2. Look for an option labeled TIMER or SCHEDULE.
  3. Set the desired start and finish time, then choose the speed (it’s shown in RPMs).
  4. Choose SAVE or START on the digital display.

If the internal timer doesn’t activate the pump at the desired time, it’s best to replace the timer.

You’ll need a pool technician or send it back to the manufacturer for a repair. If an unqualified person repairs the timer, the pool pump loses its warranty, and keeping that warranty valid is very important.

Pool Pump Timer Not Shutting Off? Here’s What To Do

It can be quite frustrating if your pool pump’s timer won’t shut off. This issue typically occurs due to incorrect programming, electrical issues in the pump, and a misunderstanding of how a pump’s timer works.

Fortunately, all of these issues are easy to fix. Here are a few solutions:

  • If your pump’s timer doesn’t shut off because it’s programmed incorrectly, there might not be an OFF tag or setting if you have an internal timer. Check the manual timer or clock to ensure there’s an OFF tag that shows your pump when it’s supposed to deactivate. Furthermore, look for an OFF time in the digital display if you have a modern pump.
  • The pool pump’s timer might have electrical issues. Loose wires and a malfunctioning timer can prevent the pump from turning on and off. Tighten the wires with the previously mentioned process, then listen to the clock closely. There should be a clicking sound if the clock is working properly on an external timer. Replace the internal timer if it won’t turn off.
  • Pool pump timers can be tricky, which is why it’s important to look for the OFF setting. Make sure it turns off in the PM or AM, whichever you desire. You might have to use a magnifying glass since external clocks use small fonts. It might seem like your timer won’t turn off, but it’s just because it turns off at 8 AM rather than 8 PM.

Hayward Pool Pump Timer Not Working? Here’s What To Do

Hayward sells quite a few pumps, including single-speed and variable-speed models.

If you have a single-speed Hayward pump, it uses an Intermatic timer (or another manual, external timer). External timers are controlled by timer trippers sitting at the desired ON and OFF times on a 1-12 clock.

So, why isn’t your Hayward pool pump timer working?

  • The timer trippers are loose, which prevents them from turning the pump on and off. Tighten them by hand to secure them.
  • There’s not enough electricity going to the timer. Test the circuit breaker with a multimeter and make sure the wires are tight.
  • Your variable-speed pump’s digital timer isn’t in-sync. Make sure you have the pump’s internal clock set to the current time; Otherwise, your ON and OFF settings won’t be in-sync with the real time.

Intermatic Pool Pump Timer Not Working? Here’s What To Do

Intermatic timers are undoubtedly the most popular external pool pump timers available. They’re easy to use and last a long time.

However, they’re not without fault. Several years of wear and tear can present a few different issues, including:

  • The timer’s motor might be broken, which means the timer needs to be replaced with the aforementioned process.
  • The current time is incorrect, which means you need to pull the clock outward and rotate it until it’s lined up with the right time.
  • Some of the LINE and LOAD wires might be loose, so tighten them with a screwdriver after turning off the circuit breaker.
  • The bottom ON and OFF tab could be flipped to the OFF position, so flip it to the ON position.
  • The installer might’ve put the wires on the wrong sides, which means you need to follow the wires to ensure they’re in the manufacturer’s recommended positions.
  • Your timer might not have timer trippers, so add an ON and OFF tag to the desired times (I suggest running the pump during the warmest hours of the day).

Intex Pool Pump Timer Not Working? Here’s What To Do

Intex pool pumps are almost always used on above-ground pools. They’re not strong enough to manage most in-ground pools, but they’re budget-friendly and easy to use.

Here’s a list of potential reasons your Intex pump’s timer isn’t working:

  • The pump isn’t plugged into the correct outlet, or the GFCI is tripped. Click RESET on the GFCI and make sure the breaker isn’t tripped, then firmly plug the pump into the wall.
  • You didn’t set the current time before setting the ON and OFF positions. Make sure the pump knows what time it is before creating a schedule.
  • The pump might’ve had a power outage. If there’s an outage in your area, you have to completely redo the whole schedule and current-time process.
  • The pump’s timer is broken. If none of these suggestions worked, there’s a high chance you’ll have to contact the manufacturer for a new timer. Keep an eye on the warranty to know if it’s covered.

Pentair Pool Pump Timer Not Working? Here’s What To Do

Pentair pumps are some of the best pumps around. They sell single-speed and variable-speed pumps, including the SuperFlo and Intelliflo.

If you have a single-speed pump, follow the advice regarding Intermatic timers and other external clocks mentioned in the troubleshooting section of this article.

If your Pentair variable-speed pump has internal timer issues, make sure you have the correct current time. Go to the CLOCK setting and cycle through the time, then choose AM or PM.

If the timer still doesn’t work, contact Pentair for a timer replacement. Their variable-speed pump timers are nearly indestructible, so it’s highly unlikely that there’s a mechanical problem.

Additional Pool Pump Troubleshooting Resources

If you have any other issues with your pool pump, check out our other pool pump troubleshooting articles:


  • Jonah Ryan

    Jonah has worked for several years in the swimming pool industry installing and repairing equipment, treating pools with chemicals, and fixing damaged liners. He also has plumbing and electrical experience with air conditioning, ceiling fans, boilers, and more. When he's not writing for Temperature Master, he's usually writing for his own websites, and

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