So your pool pump isn’t turning on by itself, but when you flip the switch in the timer box the pump does turn on. There are a few reasons why this could be happening. The first reason is that the on pin is not tight and is sliding around the timer face. If this is the case, you want to reset the pin to the appropriate on time and tighten the finger screw.

If all the pins appear to be tight there really is only one other reason that the time clock is not turning on your pool pump: Your time clock motor is dead. You can just go ahead and change the time clock’s motor if you want, but I recommend changing the whole time clock. By the time your time clock’s motor dies the contacts in the clock are normally pretty much worn out.

There is an inspection hole right at the top of the clock. If you take a flashlight and look into the inspection hole you should see gears and the gears should be turning. If they are not turning you have found your problem – the clock motor is dead.

Pool Time Clock

Let’s get started removing the old timer. The first step is to make sure all the power to the timer and pool pump is turned off. As you can see, this sub panel is labeled. I never trust the labels, though. If you have a meter handy you can test to see if you are still getting power after the breaker is turned off. You can test this by setting your meter to AC Volts 700 (or anything above 240. My meter has 100, 200, and then 700) and then testing the line wires. You can see in the picture below that the plastic shield has a diagram on it telling you exactly which lines are the line wires. Oh, by the way, this post is for a 240-volt system. If your pump is running at 115 volts the wiring is a little bit different, but the wiring diagram is pretty straightforward. If your meter reads anything above “0”, your timer is still hot and you need to continue turning off breakers until it reads “0”.

Pool Time Clock

Now that all the power to the system has been turned off you can remove the ground line and pull it out of the way.

Pool Time Clock

The power lines to the timer both in and out can be removed now as well, but I do recommend keeping track of which line went to which terminal on the timer. You can reverse the line wires or the load wires and everything will work just fine, but if you cross one of the load wires with one of the line wires, the system will not run. If you were to switch both load wires for both line wires the pump will still run but once the timer turns off it will not turn back on. If you look at the picture below you will see two white wires coming off of terminal one and terminal three. These are the power wires for the timer motor. These wires should have power all the time; otherwise the clock is in reality turning itself off when it turns the pool pump off.

Pool Time Clock

Now that all the wires are disconnected you will see a little clip at the very top of the clock plate. If you push that clip up you should be able to tilt the top of the clock towards you and lift the clock up and out of the mounting bracket.

Pool Time Clock

Well that’s it, now we just need to do everything in reverse. Click the new clock into place (most mechanical time clocks are made by Intermatic; if you go to my Amazon affiliate page I have links for both the 240-volt pool time clock as well as the 115-volt pool time clock), attach the line and load wires. Always slip the wire into the terminal on the left of the screw; that way when you tighten the screw it actually pulls the wire in versus pushing it out of the terminal. Make sure to attach the plastic shield. It is very easy to touch one of the terminals when turning the pump on manually if the shield is not in place. Nasty little shock! Go ahead and attach the ground wire. Now, to set the correct time, grab the clock face around the edges and pull out, turn the dial until the little metal arrow is lined up with the correct time. Now take your finger screws and set the on and off times (the pins are labeled). Now turn the breakers back on and you should be all set! Take your flashlight and look in the inspection hole to confirm that the gears are turning.

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