Heated Birdbath How to not turn on if above freezing?

SmartApps & Automations Automation Ideas
1

I’d like to use local weather and not a sensor.
I have an outdoor rated Z wave switch that turns on my heated birdbath. It would be great to have it not go on if the weather is above freezing. Is there a way smartthings can do this?

Thank you in advance.

2

Two Routines

  • One to turn it on at a particular time if the temp is low enough
  • One to turn if off if the temp rises above a certain temp and it is already on

2025-03-07 14.52.22
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2025-03-07 14.53.34
2025-03-07 14.53.341080×2340 114 KB

You could create a variation of the second one that turns it on when temp drops below the threshold rather than at a specific time.

1 Like
3

Awesome, Thank you!

4

I ran freeze protect with two routines: Turn on if temperature drops below X for five minutes (to filter out brief drops from open door), (2) Turn off if temperature rises above X+Y for ten minutes.

Y is your hysteresis, so the thing doesn’t keep turning on and off in short intervals. Figure out the values you need by experiment - there is substantial power savings in keeping this as low and as tight as possible.

Bonus points if your heater (the thing you turn on and off) has its own thermostat. If it does, put its target above X but below X+Y.

1 Like
5

Peter,
Sound cool. I’m interested in how you did this? I get the if equal to or below temperature, How do you do the five minutes part? Add condition Time?

Thank you,
Rob

6

Hi Rob,

this is what I have:

On -
precondition: Heater thing is Off
Condition: Temperature is below (lower threshold) for 5 minutes
Action: Turn heater thing On.

Off -
precondition: Heater thing is On
Condition: Temperature is above (upper threshold) for 10 minutes
Action: Turn heater thing Off

I’m using this to keep a room above freezing, the “heater thing” is an electric room heater on a smart plug. Its own thermostat doesn’t go lower than about 6.5 for its setpoint, so I went for (lower) and (upper) thresholds of 4C and 8C respectively. This way, with the thermostat regulating internally, the whole setup doesn’t need to turn the smart plug on and off all the time - on a typical cycle, just On once when the night gets cold, and Off in the morning when the sun comes up.

edit: I have been using weather, but now I’m using a local sensor for tighter control - these heaters use a lot of electricity. SONOFF SNZB-02P or -02D work well, they report fast temperature changes quickly which is vital here. (The Aqara sensor for example stubbornly reports once an hour, useless really for any kind of control loop.)

Hope that helps - Peter