Hi,
I have a solar pool heater that I want to turn on when the roof temp rises above 80 and turn off below 80. The problem is in the morning the temp fluctuates around 80 for a few minutes (79.5, 80.5,79.7,80.3,…), so with a simple rule it turns the pump on and off a few times until the temp doesn’t dip below 80 anymore.
What would a rule need to look like that waits until the temp doesn’t dip anymore?
Eg. If temp > 80 for 10 min then turn on pump.
Same for turning it off. If temp < 80 for 10 min then turn off.
If have created two rules. If that the right way or could I combine on/off in one rule? How would I do that?
I would simply add a 5 or 10 min delay to the rule
You could do this with 1 rule instead of 2.
First, you don’t need the predicate condition.
The rule can be triggered by temp>80
Then add the action:
Turn on pump
Wait for temp<79 -> Delay X minutes
Turn off pump
What that will do is that once the temperature is less than 79, it will wait X minutes and if it is still less than 79 at that point, it will go to the next line (Thanks @bertabcd1234 for showing me this (by showing someone else) yesterday!).
If the rule is triggered again by the temperature going over 80, it will automatically cancel and re-start the wait.
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Thank you for the advice!
Like this?
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Close! You need to put the delay on the Wait line rather than on the Off line for this to work the way you want it.
Oh, and my apologies - you have to do a wait for conditions, not events… Did I mention I just learned about this yesterday…? 
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Next attempt
Thank you for the tip - wait for condition is wait for rule in 2.2.9.
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So I expanded my pool heater automation. I’m running a fake-101 with a ds18b20 temperature probe in my pool and a temp sensor on the roof with the solar panels.
I would like to achieve the following:
Between 9:00 am and 3:58 pm (when energy is cheaper) AND
If water temp is below 82 F AND
If roof temp is greater than water temp
Run the pump
If water temp is above 82 OR it’s 3:58 pm, turn off the pump.
I came up with the following but the temp based power off does not seem to work.
Any suggestions?
The rule below sends me a temp notification every few minutes. Is there a way to only get one message when the threshold is crossed in both directions?
A few thoughts for you. Turn on logging and see what's happening. I would also consider making the roof temp > pool temp a restriction and the pool temp the trigger. I'd also update the Wait to When time is 15:58. The rule is running every few minutes because the roof temp is changing (quickly I would guess) and triggering the rule which sends notifications for each triggering. You could try to incorporate a boolean variable to limit the number of times or try the Notification app.
Hi,
Thank you for your feedback!
I reshuffled the rule based on your input. Now the rule is not firing to turn off the pump, nor turning it off if I turn on the pump switch manually.
If water < 82 turn switch on
If water > 83 OR time = 15:57 turn switch off
What am I missing?
@christian.busch Did you turn on the rule logging? If so, post the logs.
It might be waiting for a new sensor update from the pool temp sensor in order to trigger. Is there a way to trigger on temp without having to wait for a deliberate update from the temp sensor?
@christian.busch just use the Run Actions button
Well I meant automatically not manually.
Another option is to swap out your temp sensor with a virtual temp sensor. You can manually set different virtual temps to see how your rule triggers and reacts.
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Thank you for everyone’s input.
The the temp > 82 check needs to be triggered by the sensor actively sending an update from the sensor and my temp changes were not big enough to trigger frequent updates.
So I solved it by using a timer trigger and moving the temp check to the actions.
This seems to work now.
What do the experts say? Does that rule look fine or is there a better/more efficient way to achieve this?
I would normally suggest some deadband between the On and Off temperature but since you're triggering every 30 minutes I don't think it's needed. You could rewrite your two IF-THEN statements into one IF-THEN-ELSE. I'm not sure of the point of the Cancel Delayed Actions so you can eliminate that action. I would definitely change your Wait for event to 15:59 or later. I'm not sure when you 30-minute trigger starts but if your rule triggers at 15:58:30 there is nothing to turn of the heater until 9:00 the next day. Edge case? Probably but why not eliminate it if you can.
