1) Give a description of the problem
Piston not running as it should
2) What is the expected behavior?
Thermostat fan should turn on for 30 minutes if heat/cool has not run for 2 hours.
3) What is happening/not happening?
Nothing is happening. When I try manual run fan turn on for 30 minutes then turn off then immediately turn on.
4) Post a Green Snapshot of the piston
5) Attach any logs (From ST IDE and by turning logging level to Full)
(PASTE YOUR LOGS HERE BETWEEN THE MARKS)
Try… starting at line 23, remove lines 26 and below…
Set fan to On;
Send PUSH notification "message here...";
Wait 30 minutes;
Set fan to Auto;
Send PUSH notification "message here...;If I start at line 23 what will cause the ‘turn fan on’ start? Is there a way to test a piston? Like how we can evaluate a formula in excel.
Line 18 would subscribe to events from Thermostat 1 (which you can tell by the orange bolt on the left hand gutter).
There is a Test button on the bottom of the piston once you save it. Alternatively, you can create a virtual switch or to simulate the piston turning true when the switch turns on. Some folks use minimote button also.
Here’s a video an ST forum member made showing how to create a virtual device.
Line 23 based on the image you attached, the editor line might be off by a few lines. Please click Reply under the person’s post so that we’ll get notified.
I am not sure what that means. Sorry. I tried creating another piston to start fan on at 10 am and stop at 10:30 am. It works fine but it keeps looping. So fan turn off at 10:30 am and then immediately turn back on.
How about a different approach.
Happens daily at 10am.
WITH
Fan
DO
Set to on.
Wait 30 minutes.
Set to auto
EDIT.
Beat me to it. 
This looks a lot better than my commands. Also after modifying my piston it says webCoRe piston #1 is true. Used to be false. Thanks.
I modified my piston to this. After hitting ‘test’ it executes and schedules a ‘fan on’ after 2 hours. Shouldn’t the ‘fan on’ be instant since thermostat has been idle for 2 hours before I hit ‘test’?
I am not sure if the piston knows the thermostat status on first save so it started the 2 hour count after you hit test.
I have given up. For some reason my piston wont trigger. It works perfectly when I run a test. But thats it. I tried adding more conditions but that did not help. You are free to give me suggestions or ignore it.
I have a Tado system so it’s probably different than yours but I don’t control the thermostat I set the heating etc.
Do you have that option with your system.
I did not follow. I have a schedule for my thermostat. But since the weather is pleasant right now my system doesnt run very often which mean the air doesnt get circulated. I would like the fan to run for 20 minutes if there has been not cooling/heating for more than 2 hours.
What I’m saying is with Tado I never select thermostat. Everything is heating. This then sets the thermostat for temperature levels etc.
I dont think I have that option. I am asked to select device to control. For some reason the piston doesn’t seem to continuously run. I just ran a test and it works fine. But then it stops. How do I make the piston cyclic? ie. keep checking if operating state is idle?
