RainMachine has the ability to download weather forecast data from multiple weather sources, then calculates Evapotranspiration-ET and estimates the water needs for the next few days. For example, NOAA provides forecast data for the entire US with a 1.5 Mile spatial resolution, allowing RainMachine to predict the watering adjustments by Reducing, Increasing or even Preventing watering.
Here are a couple Important Factors to consider when determining why your unit behaved the way it did.
Forecasted Precipitation is the amount of rain forecasted to fall.
Temperature, Wind, Relative Humidity directly relate to how much evaporation occurs. For example, high temperatures later in the week may require RainMachine to water more than in previous days.
Freeze Protect can prevent the RainMachine from watering if the temperature goes below a certain threshold (default is 36F), avoiding irrigation water potentially freezing on your plants during a frost or cold day (Off by default).
Restrictions can be set by Month, Day, or Hour, and will override a program if there is a conflict.
Minimum Water Threshold if this is under the minimum you have set, the program will not water. This quantity will 'carry-over' to the next watering event.
Field Capacity is the amount of soil moisture or water content held in the soil after excess water has drained away and the rate of downward movement has decreased.
Once you are familiarized yourself with the variables that will Reduce/Prevent watering, you can begin to investigate:
Always start with the Web Interface, Water History page.
Go to http://my.rainmachine.com and log in with your RainMachine credentials, then choose your device from the list. You will arrive at your Dashboard, then Navigate to Settings > Water History
Here it will show the actual water times along with a reason if it did not water. Here is a list of reasons the unit will not water:
1. Stopped by user
The watering activity has been manually stopped by the user, or there was a power outage and the RainMachine device shut down during the watering activity.
2. Minimum watering time
Scheduled duration is under duration set under Settings - Restrictions - Minimum Watering Time. This feature allows users to set a minimum time for their sprinklers to run. Any time below that threshold will rollover to the next watering cycle.
3. Freeze protect
The threshold is set by the user under Settings - Restrictions - Freeze Protect. It will stop all scheduled watering activities when the minimum temperature has reached and it will automatically resume when the temperature will raise over.
4. Day restriction
Set by the user under Settings - Restrictions - Weekdays. It will stop all scheduled watering activities for the selected days.
5. Month Restricted
Set by the user under Settings - Restrictions - Months. It will stop all scheduled watering activities for the selected months.
6. Watering time reaches next day
This reason is triggered when during the day a watering activity has been postponed (sent to be the last in the watering queue) until its start time has reached the next day (over 12:00 AM) and that watering activity will not start for the current day.
7. Water surplus
This reason is triggered when the soil doesn't need more watering because of the past day rain events or evapotranspiration has been low and the water from previous irrigation is still in the soil, so there is no need for watering again. When this reason is triggered it will stop all scheduled watering activities.
8. Rain detected
is triggered when the attached hardware Rain Sensor
detects rain. To change the behavior of the Rain Sensor go to Settings - Restrictions - Rain Sensor
and choose how long the RainMachine will stop all watering activities after the Rain Sensor detected rain last time (available in our latest beta firmware update).
9. Snooze set by user
Set by the user under Settings - Snooze. This can be either set to snooze all scheduled watering activities by days, or by hours, or by minutes (available in our latest beta firmware update).
10. Program Rain Restriction
Set by the user under Programs - Edit Program - Rain Restriction. This is a sensitive option required by some municipalities authorities. If you live in an area that does not have this rule, then it should be left as Not set. If you must apply it, then keep in mind that this option will override RainMachine watering algorithm at the program start time.
An example of how the reason "Water surplus" will show:
Diagram 1.1 Water Surplus
Water Surplus is reached when the soil reaches its Field Capacity. This is typically caused by Forecasted Rain and can be viewed from the home screen of any device or web interface.
Diagram 1.2 Precipitation
In the Diagram above, notice the 0.4 inches of rain forecast for the 14th, this has caused the unit that normally waters every 2 days to Prevent Watering for a few days.
Forecasted data is wrong, it didn't rain on my property. Why?
Forecasted data will not be right 100% of the time so we include a feature to make corrections when the forecast is wrong. From web interface go to Settings > Weather > Forecast Correction
Diagram 1.3 Forecast Correction
It rained but my RainMachine still watered. Why?
RainMachine will calculate how many inches of rain are forecast, and determine how much it still needs to water (Evapotranspiration). It's not uncommon if you are only getting 0.2 inches of rain to still see your programs water a percentage of its time. You also have the ability to set a Software Rain Sensor.
Under each Program you have a setting called "Do not run the program if rain exceeds", and this will allow you to snooze the program if the adjustable desired amount is met. 1/16 inch to 1+ Inches.