What Are My Options to Protect My Pipes/Heads From Freezing Damage?


When using Flex Daily, what are my options to protect my pipes and heads from freezing damage, using the Iro 2 as my controller? Is this (below) an accurate summary?

  1. Rely on Iro’s capability to get ambient temperature information from weatherstations, hope that I can find a weather station near by, hope that the remote weather station has accurate and reliable ambient temp reporting, and hope that Iro 2’s non-adjustable fixed 32 degree threshold is sufficient. This option maintains an accurate Current Moisture Balance calculation for each zone. This option maintains ability to water a zone manually even if it’s freezing or below.

The remaining options do not (presently) maintain an accurate Current Moisture Balance calculation for each zone, nor do they allow for manually watering a single zone (my pool in my case).

  1. Connect a hard wired freeze sensor to Iro 2 terminals ? and ?. What kind of hard wired freeze sensor is required?

  2. Connect a remote freeze sensor to Iro 2 terminals ? and ?.

  3. Use an external home automation system’s relay contacts, influence by the automation system’s specified temperature, to control open/close Iro 2’s common wire connection.

Thank you for the assistance.


I am guessing that you are looking for a freeze skip option to be added to flex daily. Freeze skip looks like the only weather intelligence feature that is not already resolved with the flex daily moisture levels. That seems like a reasonable request under product suggestions.

You must keep your irrigation running all year. I blow out my zones before the first heavy frost and leave it winterized until spring, so it isn’t a priority for me.


Thank you.

You’re correct - I’m in Dallas weather such that we keep irrigation running all year. The killer is unintentionally running it when it freezing or below. Heads split, and the city issues fines if ice forms on sidewalks / streets.

I want to run my Iro 2 as ‘set and forget’ - it’s supposed to be capable of this, and for the most part it does.

One area it doesn’t is with freeze protection. You’re not going to get it, when the Iro 2 is set for full auto ('Flex Daily), unless you have a weather station nearby, that you’re comfortable you will always be connected to, that is accurate, and you’re happy with the freeze threshold set at a fixed 32 degrees.

I’d prefer to see a couple of terminals put in a future Iro generation, dedicated just for freeze monitoring. No weather to find, no Internet connection required to be maintained, and no accuracy concerns of the weather station.

This may not ever happen. Rachio advertises itself as a software company where a hardware improvement may be longer to come by, and, I don’t think Rachio has reservation of freeze protection being obtained via the Internet.

For absolute certainty that watering in freezing temps does not occur, local control is needed. Since I have a home automation system, where outside temp is one of many inputs, I’m going to put one of the automation system’s relays in series with Iro 2’s common wire out to the valves. And set the automation system to ‘trip’ the relay at 39 degrees.

Not a very elegant solution as I’ll loose tracking of moisture levels in each zone. But I don’t know of any other way than what I described above to ensure freezing temperatures are not missed by the Iro 2.


@a0128958 - I’m wondering if a one day skip event is available to be triggered by IFTTT and the automation equipment that is running? That might do the trick and allow the moisture levels to be correct.

Where I live in the Dallas area incentivizes one not to use a sprinkler system from mid November to mid February as they take that water usage during that period to calculate the sewage charge for the next year. Therefore, I have my Rachio on a schedule that ends before freezing weather typically hits. But I have to go edit the beginning and ending year on the schedule every year - I hope V3 fixes that!



I’m the same way - my sewage charge is based on water usage for a few months late Winter through early Spring.

In my case I have a separate meter for landscape watering, thus enabling me to continue landscape watering through the winter months without affecting my sewage bill.

Early on, I didn’t recognize how many dependencies the Iro 2 has to ensure watering isn’t done during freezing conditions when the Iro 2 is set on Flex Daily. I’m gaining appreciation for this fail safe feature.

Older technology controllers have terminals for a freeze sensor because they have no other means of turning on/off in freezing conditions.


Here you go. Wireless and simple. Has both rain and freeze sensor.

I’ve got one and it works just great!



If your irrigation lines run downhill, you can place a self flushing end drain on the line, which closes when under pressure, but opens to drain the line when pressure is off. It will self-flush the line each time there is an irrigation.


Now this is an excellent suggestion, that I don’t think I would have ever thought of on my own. Thank you!


If the line does NOT run continuously downhill, which is often the case, you can blow out the line with an air compressor using a suitable adapter to connect the air compressor to either a 1/2" riser thread or a pop-up sprinkler head thread.


Hey guys-

I’m going through some old threads, and couldn’t help but update this thread. Freeze skip is now available for Flex Daily schedules, we released this feature with V3.0 of the app! Hope that helps!