Which Pool Timer Do I Need?

Maintaining a healthy swimming pool is hard work. You have to make sure your pump, filter, and heater are operating correctly, meanwhile, ensuring the chemical levels in your pool water is safe for swimming. In short, it is hard work. So much work that without help, you may not be able to properly keep your pool running. Help can come in many forms when we’re referring to swimming pools. In this case though, I am referring to mechanical pool timers

Pool timers are great, especially for pool owners who aren’t home throughout the day to turn their equipment on and off. Which, if you have a swimming pool, you know is vital to the overall wellness of your pool. Depending on the timer, it may have the capability to turn your pump and heater on and off. It can also switch your dual or variable speed pump from low to high speed. Certain timers even take it a step further with freeze protection. Freeze protection shuts off your  pool equipment once the outside temperature reaches a certain degree. Another great security caution in protecting your pool equipment.

Intermatic is our go to manufacturer for pool and spa mechanical timers. Intermatic manufacturers some of the world’s vital components in the mechanical time switch industry. The pool and spa controls line was introduced to the industrial market in the late ‘50’s and still remains a valuable product line today

The question we get asked the most is, “Which timer do I need?” That question has a few variables that need to be discussed before we’re able to give you that answer. Let’s explore. 

Intermatic 156T1978A-2What Are you Trying to Control?

Instead of asking yourself which timer you need, ask yourself what exactly are you trying to control. Are you looking for a timer to just turn your pump on and off? Or, do you need one that will switch your pump from high to low speed? Maybe you need a timer that can shut off your pool equipment before it reaches freezing temperatures. Or, maybe one for all of the above. Whatever you’re trying to control, Intermatic definitely has a timer that will fit your needs. So, let’s figure out which one you need.

Turning Equipment On/Off ONLY

Most pool owners need  a timer to simply turn their pool equipment on. This can include turning on your pool pump, pool heater, booster pump, heat pump, and lighting.

The Intermatic T101 Series timer is perfect for this task. The T101 series is a mechanical time switch designed for industrial, commercial and residential applications. It features a high horsepower rating that is ideal for loads up to 40 amps resistive from 125-volts and direct 24-hour time switch control of most loads. It is offered in a plastic or a metal enclosure and in 115V or 230V.


  • 24 hour time switch
  • Equipped with one ON and one OFF tripper, but can accommodate up to 12 different ON/OFF.
  • Handles up to 40 amps
  • Rated up to 2 HP
  • Designed to be used on residential pools and spas.
  • Available in a plastic or metal enclosure





The Intermatic T104 series is designed for heavy duty industrial or commercial applications using a higher HP. Much like the T101 Series, the T104 timers are only designed to turn your pool equipment on and off. This timer comes with one “On” tripper and one “Off” tripper but can accommodate up to 12 On/Off positions.

  • Intermatic T104P3-824 hour time switch
  • Handles up to 40 amps
  • Highest HP rating at 5HP
  • Handles 120-480 Volts
  • Equipped with one ON and one OFF tripper, but can accommodate up to 12 different ON/OFF
  • Designed to be used on commercial or industrial pools.
  • Available in a plastic or metal enclosure
  • Only in 220 V




Turning Equipment ON/ OFF + Heater Protection

This is the same T104 timer with an extra feature. Timers with a built-in heater protection add extra precaution to preserving the overall wellness of your pool.

The T104P201 timer  allows pool owners to leave their homes with confidence that they won’t return home to a frozen pump or heater. With the heater protection, the timer will shut off gas heaters once the outside temperatures reach a certain degree. The heater will shut off twenty minutes before the pool pump. This eliminates  the problem of pounding and knocking due to overheated water, reduces scale and lime deposits, and extends the service life of the heater. Ideally, this timer is for pool owners with commercial pools whom would like to turn their systems on and off while adding a protection for your heater. t104p201

  • 24 hour time switch
  • Handles up to 40 amps
  • Highest HP rating at 5HP
  • Handles 120-480 Volts
  • Equipped with one ON and one OFF tripper, but can accommodate up to 12 different ON/OFF
  • Designed to be used on commercial or industrial pools.
  • Applications: Booster pumps, lighting, fans, heat pump, filter pumps with gas fired heaters



Switching Your Pump From HIGH/LOW Speeds

t106rThe Intermatic T106R timer typically wires into an existing pool timer the pool owner already has. Your existing timer will turn your pool pump ON/ OFF, while the T106R will switch the pump from high to low speeds.  Purchasing this timer alone will not turn your pump ON or OFF. If you want to control the ON/OFF settings through a timelock, you also need to purchase a T104 timer or combination timer that has both. (T10604R)

  • Provides electrical loads up to 40 Amps
  • Provides direct 24 hour control of most loads
  • Manual override
  • All models equipped with one ON/OFF tripper



Turning Pool Equipment ON/OFF + Freeze Protection

pf1103The Intermatic PF Series timers are self-contained in an indoor-outdoor, beige, rainproof enclosure and are designed to be connected to a timing or switching device. Together, they control as well as protect the Pool/Spa equipment and plumbing against freeze damage. The Control, if wired according to instructions, turns ON the Filter Pump when the air temperature (where this Control is located) drops below the temperature set by the thermostat dial (between 32˚F and 45˚F).

This timer is for pool owners with an already existing timer who are interested in adding the freeze protection for their pool equipment.  If you’re in need of a timer as well, you can purchase a combination timer that has both.

  • 120/240 V installation
  • 1.5-3HP rating
  • 45 degrees to 32 degrees with 5 degree differential


Digital Controls

Turning Your Pump ON/OFF

Intermatic PE153-3Intermatic’s NEW MINI-PE Series Digital Controls couple the standard features of the T100 Series with the convenience of digital automation.  Beyond single and two-speed pump/booster pump applications, auxiliary modes can control pumps up to 3HP as well as underwater, garden and/or fountain lighting.

Countdown and override features allow cycle interruptions when pool/spa service is required. All timing and protection associated with filter pump/booster pump combos and two-speed pumps has already been integrated into the digital software.

  • Available in both metal and plastic enclosures and with a wired remote command, freeze probe or both.
  • 5 different mode settings
  • Applications: Single speed pump/booster pump combo, two-speed pump/booster pump combo, water and fountain applications, and lighting.


Mechanical timers, although small, can play a major role in maintaining your pool’s overall wellness. If you’re still have questions on which timer is best suited for your pool, give us a call at 877-372-6038 and let us help you.

21 thoughts on “Which Pool Timer Do I Need?

  1. I need PART # 9238-201 for my 2 speed pump control box. I see that it is out of stock or discontinued everywhere. That id the exact replacement part I need, but is there something else I can get to replace it?
    If not, I’ll probably need a total control box (I guess). If that’s the case, what should I consider?

  2. Would it matter if these are installed inside near breaker box or is there a requirement that the timers go outside near the equipment. Thanks!

    1. The freeze protect is part of the motor mounted timer or the automated controls; once it senses the air temp has reached the set temp, it would kick on the pump.

      If you have disconnected power from the pump or the automated control, the freeze protection is not going to do anything.

  3. I live in the high desert in Southern California. I have a pump that i was told would come on before freezing to prevent pool damage. The new timer was installed in a pre-existing box. I have no idea how to set the timer. I have drained my pool and had to turn the whole system off as I couldn’t get the timer to turn off. I am considering replacing the timer. The current timer is like the Mini series shown on this page.

  4. I have a 1hp single speed pump ( going to eventually upgrade to a multi speed) with an intermatic timer. Can you recommend a new timer with freeze protection that will work with the current and later upgraded pump? Recommendation for a more efficient pump would also be appreciated.

    24,000 gal inground pool
    Intermatic T104P201 timer
    230V 1hp Century pump

    1. Most (if not all) variable speed pumps have a freeze protect function built into the motor’s mounted control. If you want a basic freeze protect for your single speed this will work: Intermatic PF1103 120/240V Freeze Control Thermostat. if you want something that can interface with the variable speed, either of these will work: or Intermatic PF153F

      For a 1 HP pump, a usual replacement would be the Pureline Prime 1.65. But Century makes the motor for all the major pump manufacturers but they do not make the pump housings. If you would like a more precise suggestion, I would need the model number of the pump housing.

  5. I have a intex above ground pool that is 18 X 9 and i need a plug in timer for a 2 HP Motor. Could you please recommend a timer

  6. I have a 20 year old timer for my in ground pool I noticed the timer time had to be set recently several times per week. I put my finger in the hole that says check motor and did not feel any movement. I shut off power to pool and checked voltage at connection and they were still hot. shut all juice to house and then no juice. my timer is installed in box with 4 screws not the top clip like shown in most videos. It is a 240 volt motor on the pump so does your T104 work as the # on my tamer says T1202M1 and motor WG1573 motor. I assume your WG 1573 – 10D work as a motor only. Any help will help. thanks Mike corocran

  7. The pool in my newly purchased home has a Pentair pool pump ( 1 1/2 hp 208 volt). It is controlled by a Intermatic basic T101 timer with metal box located on an outside wall. Wiring diagram inside cover only shows a 110 volt hook up. It seems like I should replace it with a 220 volt timer with a raintight enclosure.

    1. It depends on which Pentair 1-1/2 HP you have; it may be a 208-230 unit or an 110/208-230. The latter is more likely because the T101 is 120 volts only, plus I have never seen a 208 volt-only pool pump motor.

      What is the catalog or part number from your motor’s label?

  8. I see there are timers with Freeze protection to turn OFF the pump equipment at a certain temperature. I live in the south and it rarely freezes here. I leave our pool filled year around and when we expect freezing temperatures I leave the pump running overnight to prevent freezing. Is this a good idea? At what temperature do I need to turn off the pump? and when, if ever, should turn off and drain the pump to prevent freezing damage?

    1. Hey Bill, I live in the south as well (Texas). Rarely if at all do we get freezes where I get overly concerned. It shouldn’t hurt by turning your pump on, especially in the south where it dips below freezing for just a few hours late in the night. I have Freeze protection, and comes on automatically at high speed. I don’t like it at the high speed. I have a 2 speed pump, when I suspect that it will come on, I just turn on the to the low speed and keep it at the lower speed through the night. Keeps the water moving and the pump turning.

Leave a Reply

Your email address will not be published.

Recommended Resources

Century’s New V-Green Pool and Spa Motors: Part I

It is customary for manufacturers to come out with new, improved products every few years. Sure, there are some hero products...
Read Now

How do I protect my pool equipment from the weather?

May 2, 2019
In this video, we discuss how to protect pool equipment from the weather. ...
Watch Now
Which pool chlorinator to use?

What Type of Pool Chlorinator Should I Use?

​Chlorine – your pool needs it but what’s the best way to get it into the water?  While you can add...
Read Now

Looking for pool parts?

Shop Motors Shop Filters Shop Pumps Shop Salt Systems Shop Lights Shop Cleaners
Copyright © 2024 INYOpools All rights reserved