"set timer" is a correct and usable phrase in written English
You can use it when you want to tell someone to set a timer. For example, you can say, "Can you set a timer for 15 minutes?"
[stops throwing confetti just long enough to set timer so I don't forget to pick them up after school].
"First take the pizza out of the box Set the oven to 375 Pour a glass of wine Place the pizza in the oven DO NOT set timer Sip your wine Recommended cooking time is 12 to 14 minutes," she explained.
Set timer for 30 seconds.
Set timer to to a 24 hour vegetating light cycle.
When the oven reaches 425ºF, immediately reduce temp to 375ºF and set timer for 25 minutes.
Put in oven at 425 degrees for 15 minutes, then reduce heat to 350 degrees and set timer for 45 more minutes.
* Set timers to turn on lights, radios and televisions, ideally at random times.
Compose and dictate emails, ask questions about the weather, stocks, set timers.
You can also set timers or use it with other devices, including via IFTTT.
Clock App on iPhone, I tend to set timers when meetings start and we don't overrun the timer.
With built-in electronic programme guides, PVRs make recording easy with no need to set timers or buy cassettes.
