Simple Automation - Humidity Control - Am I doing this wrong?

I have a simple automation for bathroom humidity control.
If humidity rises above 75%, turn on the fan. When it drops below 74%, turn it back off.

Using the Simple Automation Rule, below, the fan turned on as expected but did not turn off when the humidity dropped. Is there something I'm doing wrong here?

What do the logs say?

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According to the screenshot, logging is not turned on for the rule. Turning it on and then seeing what’s going on would be the next step.

I would also suggest decreasing the “turn off” threshold to something like 70% or 65%.


I'll give it another try tomorrow with logging on.

If you have time and are motivated to troubleshoot today.

You could create a virtual humidity sensor, clone the rule, and then in the new rule, select that virtual sensor (make sure logging is turned on in the new rule too).

Then you can manually change the humidity value for that virtual sensor, and see what’s going on in the logs as the humidity % goes above and then below your thresholds.


I know I am not speaking to your specific question in rules - however I do the exact same thing as you but I use an app available from HPM (hubitat package manager) called Smarter Humidity Fan and it works perfectly.


I like that app and use it as well. Lots of configuration options (which I could never code for myself, or even approximate with rule machine).

But for the basic logic described in the OP, the built-in simple automation rules app should work fine.

I would suggest going through the initial troubleshooting suggested above to understand better what’s not working as intended. Perhaps it’s a device issue that will cause problems no matter what app is used for automating the bathroom fan in response to humidity levels.


BTW - that app - at first glance you'd think 'oh - this just turns the fan off and on based on the humidity' but the special magic to turn lights on and off is in the 'Additional Switches' which may not have been obvious. but as MTK advices suggests, troubleshooting the problem first would clearly be beneficial regardless of which route in the end you ultimately take.

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I highly suggest this route...because IF your fans are good enough to evacuate the air in that room I think you will 1. Find that your fan goes on and off as the humidity fluctuates during a shower. 2. you typically want that fan to run for a while after a shower to help keep the humidity from rising again.

What you have should work....but my guess is you will have a fan going on and off.

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That looks even better than using the Simple Rule approach

Though I'll still try and follow up with logging data to see what is happening with the Simple Automation Rule approach (even if just to figure out if there is a bug that can be removed and to try and get this working for the next person who tries it ).

I tried this virtual sensor route and it looks like the rule only triggers on the rise in humidity, but not the fall. I'll report this in the beta feedback.

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