# Time to calculate variables and running flows in Homey **URL:** \ **Category:** Flows\ **Created:** [March 27, 2026, 11:30am UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016 "2026-03-27T11:30:51Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Oyvind\_Lilleberg](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/oyvind_lilleberg/32/140892_2.png) [@Oyvind\_Lilleberg](https://community.homey.app/u/Oyvind_Lilleberg)\ **Post date:** [March 27, 2026, 11:30am UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/1 "2026-03-27T11:30:51Z")
I have a question about the time Homey uses to calculate variables, and running flows. I have one flow for setting the heating temperature in my house based on the outdoor temperature. The flow sets a variable (SP\_temp) to my desired heating temperature. And it runs every 30 minutes. ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/d/0/d0290ae2de3fc3c6ff2e1cf92dcfd5ff168abcaa.png) In the same flow I also calculate some variables that I use for rooms that needs a higher or lower temperature (SP\_temp\_boost+1, SP\_temp\_senk-1, and so on..) ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/d/c/dc51962eca24199505276af2a57c0df77ac383f5.png) Ultimatly I have one flow for each type of heating source in my home (one for panelovens, one for heating pump and one for floor heating). This is runned by a Heating Controller unit that sets the temperature according to us beeing on work/school or at home. But I also have built in a function to change the temperature on the sources if the SP\_temp changes before there is a new event in the Heating Controller. For example if the outdoor temperature drops during the day and I need to set up the temperature in the house. ![image](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/6/6/66652698468f665fcc89b87fb1745a2a867a04f7.png) So to my question. In my flow for the floor heating I have set each thermostat to change to different variables. I trigger this with the SP\_temp has changed trigger. Is this going to work or is the calculating (in my second screenshot) going to be to slow so it won`t update the SP\_temp\_boost+1 or SP\_temp\_senk-2 in time to set the right temperature in the third screenshot? ---
**Author:** ![Wim\_Post](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wim_post/32/56793_2.png) [@Wim\_Post](https://community.homey.app/u/Wim_Post)\ **Post date:** [March 27, 2026, 1:10pm UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/2 "2026-03-27T13:10:15Z")
For your inspiration: This flow plays sounds on my Homey 2019. The first card after the start button starts a flow (=this flow) with tag ‘doorbell’ The second trigger will wait 10 seconds and then plays the sound. Only then the top flow continues to the second card which will play a train whistle. In short: the top flow will waits until the ‘subroutine’ is finished. ![IMG_2136](https://us1.discourse-cdn.com/flex025/uploads/athom/original/3X/a/f/af9489a928fe784e82e7bc65e2ab9f6514c3e491.jpeg) ---
**Author:** ![Oyvind\_Lilleberg](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/oyvind_lilleberg/32/140892_2.png) [@Oyvind\_Lilleberg](https://community.homey.app/u/Oyvind_Lilleberg)\ **Post date:** [March 27, 2026, 1:41pm UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/3 "2026-03-27T13:41:35Z")
Thanks, but not sure how I can use it in my case. As long as the calculations goes fast enought I don’t need to delay the actions. Also the flows are quite big with lots of triggers, so i think it then will be quite useless. But thanks for the inspiration. Could be useful in other cases 🙂 ---
**Author:** ![Rmb](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/rmb/32/79135_2.png) [@Rmb](https://community.homey.app/u/Rmb)\ **Post date:** [March 27, 2026, 2:04pm UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/4 "2026-03-27T14:04:05Z")
When SP-temp has changed both flows will run. So you need a different trigger to start the latest flow, or call one flow from the other or combine the 2 flows in one flow. ---
**Author:** ![Wim\_Post](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wim_post/32/56793_2.png) [@Wim\_Post](https://community.homey.app/u/Wim_Post)\ **Post date:** [March 27, 2026, 2:14pm UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/5 "2026-03-27T14:14:20Z")
> [@Oyvind\_Lilleberg](#): > > Is this going to work or is the calculating (in my second screenshot) going to be to slow so it won`t update the SP\_temp\_boost+1 or SP\_temp\_senk-2 in time to set the right temperature in the third screenshot? What I ment to say: if you do your calculations in a ‘subroutine’ you are sure the calculations are finished before continuing the flow. ---
**Author:** ![Oyvind\_Lilleberg](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/oyvind_lilleberg/32/140892_2.png) [@Oyvind\_Lilleberg](https://community.homey.app/u/Oyvind_Lilleberg)\ **Post date:** [March 28, 2026, 6:41am UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/6 "2026-03-28T06:41:50Z")
Did some testing now and found out that if I added a 10 second delay after the SP\_temp has changed in the last flow, it had enough time to calculate and set the right values. ---
**Author:** ![Wim\_Post](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/wim_post/32/56793_2.png) [@Wim\_Post](https://community.homey.app/u/Wim_Post)\ **Post date:** [March 28, 2026, 10:33am UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/7 "2026-03-28T10:33:43Z")
Be aware that the animation during testing slows down a flow with many seconds. In real life it’s only a split second. ---
**Author:** ![Rmb](https://sea1.discourse-cdn.com/flex025/user_avatar/community.homey.app/rmb/32/79135_2.png) [@Rmb](https://community.homey.app/u/Rmb)\ **Post date:** [April 3, 2026, 8:27am UTC](https://community.homey.app/t/time-to-calculate-variables-and-running-flows-in-homey/153016/8 "2026-04-03T08:27:33Z")
It is a solution, but not a solid solution 😄