How to Program an Intermatic T100 Series Timer


  3.5 out of 5 stars on 15 ratings
(Click on a star to add your rating)

The Intermatic T100 Series Timers are heavy-duty time switch mechanisms. They are designed for commercial, industrial and residential applications. The following steps will provide a guide on how to program the T100 series timer.

Please click here to view the Intermatic Timers.   

Things You'll Need

Step by Step


Step 1

The first part of programming the Intermatic timer is to set the current time. Locate the yellow Clock-Dial inside the timer box.

Step 2

There is a silver Time Pointer on the Clock-Dial. This Time Pointer will point directly to the current time.

Step 3

To set the time, pull the Intermatic Clock-Dial outward. Turn the dial in either direction and align the exact time of day on the Clock-Dial to the Time Pointer. The picture displays the timer set to 12:00 pm.

Please click here to view Intermatic timer parts. 

Step 4

The next steps will demonstrate how to set the trippers. The trippers will determine when the equipment will turn on and off.

Step 5

Locate the "On" tripper. The "On" tripper is typically green and will be labeled "On".

Step 6

To set the "On" tripper, hold the tripper against the desired time and tighten the tripper screw firmly. The picture displays the "On" tripper set at 8:00 am.

Step 7

Locate the "Off" tripper. The "Off" tripper is typically gold and will be labeled "Off". 

Please click here to view Intermatic timers. 

Step 8

To set the "Off" tripper, hold the tripper against the desired time and tighten the tripper screw firmly. The picture displays the "Off" tripper set at 4:00 pm.

Step 9

The Intermatic T100 Series Timer is now programmed. Close the timer door and enjoy the energy savings of using a timer.

Step 10

Note: The timer has a red lever that can be used to manually override the current setting on the timer. If your timer is in "off" mode and you want to turn it "on", you can flip the red lever to "on". The timer will remain in "on" mode until the timer "off" tripper comes around or until you flip the lever to "off".


(1 to 33 of 33)

 Posted: 8/23/2021 

Do I flip the lever to manual or off for the timer to come on and off on it's own

InyoPools Product Specialist  Posted: 8/24/2021 

The lever has a middle/neutral position. Set the lever there if you want the timer to work normally.

 Posted: 11/21/2020 

Hello why would my pool guy have an on tab at2am and off at 6pm and the another on at 11 am?

InyoPools Product Specialist  Posted: 12/3/2020 

Are you missing an OFF tripper? It sounds like you have two ON and one OFF. Also, did you ask him why he scheduled it in such a manner? That would be the simplest way to get an answer; straight from the horse's mouth

Anonymous  Posted: 12/4/2020 

Thank you for the reply!! Not missing the second off. I will reach out to him. Just don’t know the reason why!!!

InyoPools Product Specialist  Posted: 12/7/2020 

If you get an answer from your pool company, can you let us know? Now, I am curious.

 Posted: 7/1/2020 

How do I set the timer to start on the half hour?

InyoPools Product Specialist  Posted: 8/26/2020 

The face of the timer shows the hours in increments of two, with a long bold line between the number to denote the 1, 3, 5 and so on. The incremental lines between a number and that bold line denote the 15, 30, 45-minute marks in that hour. Set the tripper on the middle one of those marks.

 Posted: 6/24/2020 

Why would my timer have (2) on triggers and (2) off triggers. We are having an issue with the timer not tripping and the filter just running?

InyoPools Product Specialist  Posted: 9/24/2020 

The multip[le sets of on/off trippers are so that you can schedule more than one run time for your pump (or whatever the timer is controlling)

 Posted: 4/20/2020 

Are the on and off clips interchangeable? My off has corroded. I have an extra on. Wondering if the second on will toggle ithe timer off or if I need to buy another set to get a replacement off.

InyoPools Product Specialist  Posted: 4/24/2020 

The trippers are not interchangeable; the on and off have different shapes to be able to affect the switch that controls power to the equipment.

Anonymous  Posted: 2/3/2020 

I’m not sure the model of the timer I have as it was already installed when I moved in.There is a red (On) and grey(off) tripper. For years it operated ok but now it does not turn off. How can I reset it ? Thks

InyoPools Product Specialist  Posted: 2/10/2020 

The process of resetting it would be based on the make and model of the timer. We will need a model number off the timer face or box label.

 Posted: 12/3/2019 

I would like to temporarily turn off my timer. We received a lot of snow and the outdoor lights are covered by many inches of snow- seems silly to have them burning.

InyoPools Product Specialist  Posted: 12/4/2019 

For this Intermatic 1000 series timer, you would just need to unscrew and remove the on and off trippers on the yellow circular dial. 

Anonymous  Posted: 3/31/2019 

The system is simple and straight forward. The only problem I had was the hours could be confusing as they are not too clearly marked but I think I've got it now.

 Posted: 4/29/2018 

Thank you!!! when I moved into my house the time was already there in my tool house - operating an outdoor flood light. After a year the bulb blew and I couldn't find anyone to climb up HIGH to replace it for me. It's been 7 years! FINALLY a young man next door was able to climb up and replace the bulb. BUT THEN I discovered that over the years the "on" tripper had fallen off and was gone. I found the part on line and now have ordered it. It had been so long that I forgot how to set the machine. Your instructions reinstated my memory and it is working!!!! Thank you for the help.

Anonymous  Posted: 4/18/2018 

This was a very helpful article. I appreciate your expertise.

 Posted: 1/24/2018 

Anonymous (trippers) - The two On and Off trippers are required to program the timer. They should be come with the timer often taped inside the cover. Check the packaging material. If you do not find them, check with your dealer. If you bought the timer from us, give us a call and we will ship them out to you.

Anonymous  Posted: 1/18/2018 

The ON and one OFF tripper are not included . How would I go about setting the timer?

InyoPools Product Specialist  Posted: 7/11/2017 

Anonymous (timer dial) - Your problem could be due to one of two failures. Either your clock motor is not running or your clock mechanism is jammed. See our guides on "How To Replace an Intermatic T104 Clock Motor" or "How to Replace an Intermatic T104 Mechanism".

Anonymous  Posted: 7/10/2017 

If my yellow clock dial is not moving but my manual on/off red lever works....does anyone know what could be a remedy to get the clock dial running again?

InyoPools Product Specialist  Posted: 8/12/2016 

Luna - See our guide on "How To Install an Intermatic T104 Timer". Note, this guide shows how to install a T104 series timer used for 220V circuits. If you have an 110V circuit, you will want ot buy a T101 series timer. The installation is the same.

 Posted: 8/11/2016 

how can I switch form manual to auto timer?

 Posted: 10/30/2019 

When resetting the on /off should the manual lever be ON ?

InyoPools Product Specialist  Posted: 11/4/2019 

It really does not matter whether it is in the on or off position to adjust the trippers. 

InyoPools Product Specialist  Posted: 6/20/2016 

Timeconsumer - I assume that Polaris runs on 120V since the T101P timer is for 120V. You have 3 options to fix this timer: replace the whole timer; replace the timer mechanism; or replace just the timer clock. I generally recommend replacing the timer mechanism (includes the clock) since the gears tend to bind when the timer gets old.

 Posted: 6/18/2016 

I had an electrician come out and replace my timer for my pool pump. He wired everything differently because the pump is only on(digital screen) when the timer is on. Previously I had to shut off the circuit braker to have the pump not getting power. he replaced it with a T104P. The other timer for the polaris is T101P . The clock does not turn now.It worked last year. Is the wiring incorrect or could the clock just be broken. When I switch it on the polaris runs but not the clock. Can I just replace a part or do I need another Timer. Thanks

InyoPools Product Specialist  Posted: 5/14/2015 

Wgbauer8 - Yes. The silver hour pointer is secured in a fixed position at 6-oclock.The yellow clock dial rotates around it. Sounds like you are good to go.

 Posted: 5/13/2015 

I accidently removed the silver permenant hour pointer when I was replacing the timer motor on my T-100 I put it back on as it was facing the "6 O' clock" position. Is this all I need to do ?

InyoPools Product Specialist  Posted: 11/24/2013 

Manual Lever - The timer has a red lever that can be used to manually override the current setting on the timer. If your timer is in "off" mode and you want to turn it "on", you can flip the red lever to "on". The timer will remain in "on" mode until the timer "off" tripper comes around or until you flip the lever to "off". I will add this note to the guide. Thanks for your input.

Anonymous  Posted: 11/23/2013 

The instructions should go one step further after installing the trippers.

There is a manual on off lever as well.

What should that be set at for automatic operation.